From 0501c1c5705e048c618f030870703fd763a491a2 Mon Sep 17 00:00:00 2001 From: Glenn Randers-Pehrson Date: Wed, 11 Jan 2012 14:00:52 -0600 Subject: [PATCH] [libpng16] Describe new simplified API in the manual pages and cleaned up some indentation problems. --- ANNOUNCE | 5 +- CHANGES | 3 +- libpng-manual.txt | 417 ++++++++++++++++---- libpng.3 | 958 ++++++++++++++++++---------------------------- 4 files changed, 726 insertions(+), 657 deletions(-) diff --git a/ANNOUNCE b/ANNOUNCE index 31ed31207..284970eb5 100644 --- a/ANNOUNCE +++ b/ANNOUNCE @@ -1,5 +1,5 @@ -Libpng 1.6.0beta05 - December 30, 2011 +Libpng 1.6.0beta05 - January 11, 2012 This is not intended to be a public release. It will be replaced within a few weeks by a public version or by another test version. @@ -104,7 +104,8 @@ Version 1.6.0beta04 [December 30, 2011] Revised contrib/pngminus/pnm2png.c to avoid warnings when png_uint_32 and unsigned long are of different sizes. -Version 1.6.0beta05 [December 30, 2011] +Version 1.6.0beta05 [January 11, 2012] + Updated manual with description of the simplified API (copied from png.h) Send comments/corrections/commendations to png-mng-implement at lists.sf.net (subscription required; visit diff --git a/CHANGES b/CHANGES index a4988a20e..d2784883a 100644 --- a/CHANGES +++ b/CHANGES @@ -3855,7 +3855,8 @@ Version 1.6.0beta04 [December 30, 2011] Revised contrib/pngminus/pnm2png.c to avoid warnings when png_uint_32 and unsigned long are of different sizes. -Version 1.6.0beta05 [December 30, 2011] +Version 1.6.0beta05 [January 11, 2012] + Updated manual with description of the simplified API (copied from png.h) Send comments/corrections/commendations to png-mng-implement at lists.sf.net (subscription required; visit diff --git a/libpng-manual.txt b/libpng-manual.txt index ceb80bf6d..d6e698b2a 100644 --- a/libpng-manual.txt +++ b/libpng-manual.txt @@ -1,6 +1,6 @@ libpng-manual.txt - A description on how to use and modify libpng - libpng version 1.6.0beta05 - December 30, 2011 + libpng version 1.6.0beta05 - January 11, 2012 Updated and distributed by Glenn Randers-Pehrson Copyright (c) 1998-2011 Glenn Randers-Pehrson @@ -11,7 +11,7 @@ libpng-manual.txt - A description on how to use and modify libpng Based on: - libpng versions 0.97, January 1998, through 1.6.0beta05 - December 30, 2011 + libpng versions 0.97, January 1998, through 1.6.0beta05 - January 11, 2012 Updated and distributed by Glenn Randers-Pehrson Copyright (c) 1998-2011 Glenn Randers-Pehrson @@ -34,17 +34,18 @@ libpng-manual.txt - A description on how to use and modify libpng II. Structures III. Reading IV. Writing - V. Modifying/Customizing libpng - VI. MNG support - VII. Changes to Libpng from version 0.88 - VIII. Changes to Libpng from version 1.0.x to 1.2.x - IX. Changes to Libpng from version 1.0.x/1.2.x to 1.4.x - X. Changes to Libpng from version 1.4.x to 1.5.x - XI. Changes to Libpng from version 1.5.x to 1.6.x - XII. Detecting libpng - XIII. Source code repository - XIV. Coding style - XV. Y2K Compliance in libpng + V. Simplified API + VI. Modifying/Customizing libpng + VII. MNG support + VIII. Changes to Libpng from version 0.88 + IX. Changes to Libpng from version 1.0.x to 1.2.x + X. Changes to Libpng from version 1.0.x/1.2.x to 1.4.x + XI. Changes to Libpng from version 1.4.x to 1.5.x + XII. Changes to Libpng from version 1.5.x to 1.6.x + XIII. Detecting libpng + XIV. Source code repository + XV. Coding style + XVI. Y2K Compliance in libpng I. Introduction @@ -707,7 +708,8 @@ assumes that the PNG data matches your system, to keep this default call: or you can use the fixed point equivalent: - png_set_gamma_fixed(png_ptr, PNG_FP_1*screen_gamma, PNG_FP_1/screen_gamma); + png_set_gamma_fixed(png_ptr, PNG_FP_1*screen_gamma, + PNG_FP_1/screen_gamma); If you don't know the gamma for your system it is probably 2.2 - a good approximation to the IEC standard for display systems (sRGB). If images are @@ -719,12 +721,15 @@ display driver, a few systems, including older Macs, change the response by default. As of 1.5.4 three special values are available to handle common situations: - PNG_DEFAULT_sRGB: Indicates that the system conforms to the IEC 61966-2-1 - standard. This matches almost all systems. - PNG_GAMMA_MAC_18: Indicates that the system is an older (pre Mac OS 10.6) - Apple Macintosh system with the default settings. - PNG_GAMMA_LINEAR: Just the fixed point value for 1.0 - indicates that the - system expects data with no gamma encoding. + PNG_DEFAULT_sRGB: Indicates that the system conforms to the + IEC 61966-2-1 standard. This matches almost + all systems. + PNG_GAMMA_MAC_18: Indicates that the system is an older + (pre Mac OS 10.6) Apple Macintosh system with + the default settings. + PNG_GAMMA_LINEAR: Just the fixed point value for 1.0 - indicates + that the system expects data with no gamma + encoding. You would use the linear (unencoded) value if you need to process the pixel values further because this avoids the need to decode and reencode each @@ -741,11 +746,11 @@ Libpng only supports composing onto a single color (using png_set_background; see below). Otherwise you must do the composition yourself and, in this case, you may need to call png_set_alpha_mode: -#if PNG_LIBPNG_VER >= 10504 - png_set_alpha_mode(png_ptr, mode, screen_gamma); -#else - png_set_gamma(png_ptr, screen_gamma, 1.0/screen_gamma); -#endif + #if PNG_LIBPNG_VER >= 10504 + png_set_alpha_mode(png_ptr, mode, screen_gamma); + #else + png_set_gamma(png_ptr, screen_gamma, 1.0/screen_gamma); + #endif The screen_gamma value is the same as the argument to png_set_gamma; however, how it affects the output depends on the mode. png_set_alpha_mode() sets the @@ -1165,27 +1170,32 @@ pointer into the info_ptr is returned for any complex types. int_file_gamma - 100,000 times the gamma at which the file is written - png_get_cHRM(png_ptr, info_ptr, &white_x, &white_y, &red_x, &red_y, - &green_x, &green_y, &blue_x, &blue_y) - png_get_cHRM_XYZ(png_ptr, info_ptr, &red_X, &red_Y, &red_Z, &green_X, - &green_Y, &green_Z, &blue_X, &blue_Y, &blue_Z) - png_get_cHRM_fixed(png_ptr, info_ptr, &int_white_x, &int_white_y, - &int_red_x, &int_red_y, &int_green_x, &int_green_y, - &int_blue_x, &int_blue_y) + png_get_cHRM(png_ptr, info_ptr, &white_x, &white_y, &red_x, + &red_y, &green_x, &green_y, &blue_x, &blue_y) + png_get_cHRM_XYZ(png_ptr, info_ptr, &red_X, &red_Y, &red_Z, + &green_X, &green_Y, &green_Z, &blue_X, &blue_Y, + &blue_Z) + png_get_cHRM_fixed(png_ptr, info_ptr, &int_white_x, + &int_white_y, &int_red_x, &int_red_y, + &int_green_x, &int_green_y, &int_blue_x, + &int_blue_y) png_get_cHRM_XYZ_fixed(png_ptr, info_ptr, &int_red_X, &int_red_Y, - &int_red_Z, &int_green_X, &int_green_Y, &int_green_Z, - &int_blue_X, &int_blue_Y, &int_blue_Z) + &int_red_Z, &int_green_X, &int_green_Y, + &int_green_Z, &int_blue_X, &int_blue_Y, + &int_blue_Z) {white,red,green,blue}_{x,y} - A color space encoding specified using the chromaticities - of the end points and the white point. (PNG_INFO_cHRM) + A color space encoding specified using the + chromaticities of the end points and the + white point. (PNG_INFO_cHRM) {red,green,blue}_{X,Y,Z} - A color space encoding specified using the encoding end - points - the CIE tristimulus specification of the intended - color of the red, green and blue channels in the PNG RGB - data. The white point is simply the sum of the three end - points. (PNG_INFO_cHRM) + A color space encoding specified using the + encoding end points - the CIE tristimulus + specification of the intended color of the red, + green and blue channels in the PNG RGB data. + The white point is simply the sum of the three + end points. (PNG_INFO_cHRM) png_get_sRGB(png_ptr, info_ptr, &srgb_intent); @@ -1589,17 +1599,19 @@ Within the matrix, "A" means the transformation is obtained by png_set_add_alpha(). "X" means the transformation is obtained by png_set_expand(). "1" means the transformation is obtained by - png_set_expand_gray_1_2_4_to_8() (and by png_set_expand() if there - is no transparency in the original or the final format). + png_set_expand_gray_1_2_4_to_8() (and by png_set_expand() + if there is no transparency in the original or the final + format). "C" means the transformation is obtained by png_set_gray_to_rgb(). "G" means the transformation is obtained by png_set_rgb_to_gray(). "P" means the transformation is obtained by png_set_expand_palette_to_rgb(). "p" means the transformation is obtained by png_set_packing(). "Q" means the transformation is obtained by png_set_quantize(). - "T" means the transformation is obtained by png_set_tRNS_to_alpha(). - "B" means the transformation is obtained by png_set_background(), or - png_strip_alpha(). + "T" means the transformation is obtained by + png_set_tRNS_to_alpha(). + "B" means the transformation is obtained by + png_set_background(), or png_strip_alpha(). When an entry has multiple transforms listed all are required to cause the right overall transformation. When two transforms are separated by a comma @@ -1684,8 +1696,8 @@ with alpha. if (color_type == PNG_COLOR_TYPE_RGB || color_type == PNG_COLOR_TYPE_RGB_ALPHA) - png_set_rgb_to_gray(png_ptr, error_action, double red_weight, - double green_weight); + png_set_rgb_to_gray(png_ptr, error_action, + double red_weight, double green_weight); error_action = 1: silently do the conversion @@ -1707,7 +1719,8 @@ with alpha. In the corresponding fixed point API the red_weight and green_weight values are simply scaled by 100,000: - png_set_rgb_to_gray(png_ptr, error_action, png_fixed_point red_weight, + png_set_rgb_to_gray(png_ptr, error_action, + png_fixed_point red_weight, png_fixed_point green_weight); If you have set error_action = 1 or 2, you can @@ -3450,7 +3463,283 @@ if you transfer responsibility for free'ing text_ptr from libpng to your application, your application must not separately free those members. For a more compact example of writing a PNG image, see the file example.c. -V. Modifying/Customizing libpng +V. Simplified API + +The simplified API, which became available in libpng-1.6.0, hides the details +of both libpng and the PNG file format itself. +It allows PNG files to be read into a very limited number of +in-memory bitmap formats or to be written from the same formats. If these +formats do not accomodate your needs then you can, and should, use the more +sophisticated APIs above - these support a wide variety of in-memory formats +and a wide variety of sophisticated transformations to those formats as well +as a wide variety of APIs to manipulate ancilliary information. + +To read a PNG file using the simplified API: + + 1) Declare a 'png_image' structure (see below) on the + stack and memset() it to all zero. + + 2) Call the appropriate png_image_begin_read... function. + + 3) Set the png_image 'format' member to the required + format and allocate a buffer for the image. + + 4) Call png_image_finish_read to read the image into + your buffer. + +There are no restrictions on the format of the PNG input itself; all valid +color types, bit depths, and interlace methods are acceptable, and the +input image is transformed as necessary to the requested in-memory format +during the png_image_finish_read() step. + +To write a PNG file using the simplified API: + + 1) Declare a 'png_image' structure on the stack and memset() + it to all zero. + + 2) Initialize the members of the structure that describe the + image, setting the 'format' member to the format of the + image in memory. + + 3) Call the appropriate png_image_write... function with a + pointer to the image to write the PNG data. + +png_image is a structure that describes the in-memory format of an image +when it is being read or define the in-memory format of an image that you +need to write. The "png_image" structure contains the following members: + + png_uint_32 width Image width in pixels (columns) + png_uint_32 height Image height in pixels (rows) + png_uint_32 format Image format as defined below + png_uint_32 flags A bit mask containing informational flags + png_controlp opaque Initialize to NULL, free with png_image_free + +In the event of an error or warning the following field will be set to a +non-zero value and the 'message' field will contain a '\0' terminated +string with the libpng error or warning message. If both warnings and +an error were encountered, only the error is recorded. If there +are multiple warnings, only the first one is recorded. + +As of libpng-1.6.0 the values are + 0 - no warning or error + 1 - error + 2 - warning + + png_uint_32 warning_or_error; + char message[64]; + +The pixels (samples) of the image have one to four channels whose components +have original values in the range 0 to 1.0: + + 1: A single gray or luminance channel (G). + 2: A gray/luminance channel and an alpha channel (GA). + 3: Three red, green, blue color channels (RGB). + 4: Three color channels and an alpha channel (RGBA). + +The channels are encoded in one of two ways: + + a) As a small integer, value 0..255, contained in a (png_byte). For the +alpha channel the original value is simply value/255. For the color or +luminance channels the value is encoded according to the sRGB specification +and matches the 8-bit format expected by typical display devices. + +The color/gray channels are not scaled (pre-multiplied) by the alpha +channel and are suitable for passing to color management software. + + b) As a value in the range 0..65535, contained in a (png_uint_16). All +channels can be converted to the original value by dividing by 65535; all +channels are linear. Color channels use the RGB encoding (RGB end-points) of +the sRGB specification. This encoding is identified by the +PNG_FORMAT_FLAG_LINEAR flag below. + +When an alpha channel is present it is expected to denote pixel coverage +of the color or luminance channels and is returned as an associated alpha +channel: the color/gray channels are scaled (pre-multiplied) by the alpha +value. + +PNG_FORMAT_* + +The #defines to be used in png_image::format. Each #define identifies a +particular layout of channel data and, if present, alpha values. There are +separate defines for each of the two channel encodings. + +A format is built up using single bit flag values. Not all combinations are +valid: use the bit flag values below for testing a format returned by the +read APIs, but set formats from the derived values. + +NOTE: libpng can be built with particular features disabled, if you see +compiler errors because the definition of one of the following flags has been +compiled out it is because libpng does not have the required support. It is +possible, however, for the libpng configuration to enable the format on just +read or just write; in that case you may see an error at run time. You can +guard against this by checking for the definition of: + + PNG_SIMPLIFIED_{READ,WRITE}_{BGR,AFIRST}_SUPPORTED + + PNG_FORMAT_FLAG_ALPHA 0x01 format with an alpha channel + PNG_FORMAT_FLAG_COLOR 0x02 color format: otherwise grayscale + PNG_FORMAT_FLAG_LINEAR 0x04 png_uint_16 channels else png_byte + PNG_FORMAT_FLAG_BGR 0x08 BGR colors, else order is RGB + PNG_FORMAT_FLAG_AFIRST 0x10 alpha channel comes first + +Supported formats are as follows. Future versions of libpng may support more +formats; for compatibility with older versions simply check if the format +macro is defined using #ifdef. These defines describe the in-memory layout +of the components of the pixels of the image. + +First the single byte formats: + + PNG_FORMAT_GRAY 0 + PNG_FORMAT_GA PNG_FORMAT_FLAG_ALPHA + PNG_FORMAT_AG (PNG_FORMAT_GA|PNG_FORMAT_FLAG_AFIRST) + PNG_FORMAT_RGB PNG_FORMAT_FLAG_COLOR + PNG_FORMAT_BGR (PNG_FORMAT_FLAG_COLOR|PNG_FORMAT_FLAG_BGR) + PNG_FORMAT_RGBA (PNG_FORMAT_RGB|PNG_FORMAT_FLAG_ALPHA) + PNG_FORMAT_ARGB (PNG_FORMAT_RGBA|PNG_FORMAT_FLAG_AFIRST) + PNG_FORMAT_BGRA (PNG_FORMAT_BGR|PNG_FORMAT_FLAG_ALPHA) + PNG_FORMAT_ABGR (PNG_FORMAT_BGRA|PNG_FORMAT_FLAG_AFIRST) + +Then the linear (png_uint_16) formats. When naming these "Y" is used to +indicate a luminance (gray) channel. The component order within the pixel +is always the same - there is no provision for swapping the order of the +components in the linear format. + + PNG_FORMAT_LINEAR_Y PNG_FORMAT_FLAG_LINEAR + PNG_FORMAT_LINEAR_Y_ALPHA + (PNG_FORMAT_FLAG_LINEAR|PNG_FORMAT_FLAG_ALPHA) + PNG_FORMAT_LINEAR_RGB + (PNG_FORMAT_FLAG_LINEAR|PNG_FORMAT_FLAG_COLOR) + PNG_FORMAT_LINEAR_RGB_ALPHA + (PNG_FORMAT_FLAG_LINEAR|PNG_FORMAT_FLAG_COLOR| + PNG_FORMAT_FLAG_ALPHA) + +PNG_IMAGE macros + +These are convenience macros to derive information from a png_image structure: + + PNG_IMAGE_CHANNELS(fmt) + Returns the total number of channels in a given format: 1..4 + + PNG_IMAGE_COMPONENT_SIZE(fmt) + Returns the size in bytes of a single component of a pixel + in the image. + + PNG_IMAGE_PIXEL_SIZE(fmt) + Returns the size in bytes of a single pixel in the image. + + PNG_IMAGE_ROW_STRIDE(image) + Returns the total number of components in a single row + of the image; this is the minimum 'row stride', the minimum + count of components between each row. + + PNG_IMAGE_BUFFER_SIZE(image, row_stride) + Returns the size, in bytes, of an image buffer given + a png_image and a row stride - the number of components to + leave space for in each row. + + PNG_IMAGE_SIZE(image) + Returns the size, in bytes, of the image in memory given + just a png_image; the row stride is the minimum stride + required for the image. + +PNG_IMAGE_FLAG_ + +Flags containing additional information about the image are held + in the 'flags' field of png_image. + + PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB + This indicates the the RGB values of the in-memory + bitmap do not correspond to the red, green and blue + end-points defined by sRGB. + +READ APIs + + The png_image passed to the read APIs must have been initialized by setting + the png_controlp field 'opaque' to NULL (or, better, memset the whole thing.) + + int png_image_begin_read_from_file( png_imagep image, + const char *file_name) + + The named file is opened for read and the image header + is filled in from the PNG header in the file. + + + int png_image_begin_read_from_stdio (png_imagep image, + FILE* file) + + The PNG header is read from the stdio FILE object. + + int png_image_begin_read_from_memory(png_imagep image, + png_const_voidp memory, png_size_t size) + + The PNG header is read from the given memory buffer. + + int png_image_finish_read(png_imagep image, + png_colorp background, void *buffer, png_int_32 row_stride)); + + Finish reading the image into the supplied buffer and + clean up the png_image structure. + + row_stride is the step, in png_byte or png_uint_16 units + as appropriate, between adjacent rows. A positive stride + indicates that the top-most row is first in the buffer - + the normal top-down arrangement. A negative stride + indicates that the bottom-most row is first in the buffer. + + background need only be supplied if an alpha channel must + be removed from a png_byte format and the removal is to be + done by compositing on a solid color; otherwise it may be + NULL and any composition will be done directly onto the + buffer. The value is an sRGB color to use for the + background, for grayscale output the green channel is used. + + For linear output removing the alpha channel is always done + by compositing on black. + + void png_image_free(png_imagep image) + + Free any data allocated by libpng in image->opaque, + setting the pointer to NULL. May be called at any time + after the structure is initialized. + + +WRITE APIS + +For write you must initialize a png_image structure to describe the image to +be written: + + opaque: must be initialized to NULL + width: image width in pixels + height: image height in rows + format: the format of the data you wish to write + flags: set to 0 unless one of the defined flags applies; set + PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB for color format images + where the RGB values do not correspond to the colors in sRGB. + + int png_image_write_to_file, (png_imagep image, + const char *file, int convert_to_8bit, const void *buffer, + png_int_32 row_stride)); + + Write the image to the named file. + + int png_image_write_to_stdio(png_imagep image, FILE *file, + int convert_to_8_bit, const void *buffer, png_int_32 row_stride) + + Write the image to the given (FILE*). + +With all write APIs if image is in one of the linear formats with +(png_uint_16) data then setting convert_to_8_bit will cause the output to be +a (png_byte) PNG gamma encoded according to the sRGB specification, otherwise +a 16-bit linear encoded PNG file is written. + +With all APIs row_stride is handled as in the read APIs - it is the spacing +from one row to the next in component sized units (float) and if negative +indicates a bottom-up row layout in the buffer. + +Note that the write API does not support interlacing, sub-8-bit pixels, +and indexed (paletted) images. + +VI. Modifying/Customizing libpng There are two issues here. The first is changing how libpng does standard things like memory allocation, input/output, and error handling. @@ -3871,7 +4160,7 @@ When PNG_DEBUG = 1, the macros are defined, but only png_debug statements having level = 0 will be printed. There aren't any such statements in this version of libpng, but if you insert some they will be printed. -VI. MNG support +VII. MNG support The MNG specification (available at http://www.libpng.org/pub/mng) allows certain extensions to PNG for PNG images that are embedded in MNG datastreams. @@ -3898,7 +4187,7 @@ or any other MNG chunks; your application must provide its own support for them. You may wish to consider using libmng (available at http://www.libmng.com) instead. -VII. Changes to Libpng from version 0.88 +VIII. Changes to Libpng from version 0.88 It should be noted that versions of libpng later than 0.96 are not distributed by the original libpng author, Guy Schalnat, nor by @@ -3950,7 +4239,7 @@ application: png_uint_32 application_vn = PNG_LIBPNG_VER; -VIII. Changes to Libpng from version 1.0.x to 1.2.x +IX. Changes to Libpng from version 1.0.x to 1.2.x Support for user memory management was enabled by default. To accomplish this, the functions png_create_read_struct_2(), @@ -4047,7 +4336,7 @@ which also expands tRNS to alpha was replaced with png_set_expand_gray_1_2_4_to_8() which does not. It has been deprecated since libpng-1.0.18 and 1.2.9. -IX. Changes to Libpng from version 1.0.x/1.2.x to 1.4.x +X. Changes to Libpng from version 1.0.x/1.2.x to 1.4.x Private libpng prototypes and macro definitions were moved from png.h and pngconf.h into a new pngpriv.h header file. @@ -4155,7 +4444,7 @@ was renamed to PNG_READ_QUANTIZE_SUPPORTED. We removed the trailing '.' from the warning and error messages. -X. Changes to Libpng from version 1.4.x to 1.5.x +XI. Changes to Libpng from version 1.4.x to 1.5.x From libpng-1.4.0 until 1.4.4, the png_get_uint_16 macro (but not the function) incorrectly returned a value of type png_uint_32. @@ -4445,7 +4734,10 @@ pngusr.h a system builder may also define equivalent options in pngusr.dfa DFA_XTRA to the file name. The makefiles in contrib/pngminim illustrate how to do this, and a case where pngusr.h is still required. -XI. Changes to Libpng from version 1.5.x to 1.6.x +XII. Changes to Libpng from version 1.5.x to 1.6.x + +A "simplified API" has been added (see documentation in png.h and a simple +example in contrib/examples/pngtopng.c) We no longer include string.h in png.h. The include statement has been moved to pngpriv.h, where it is not accessible by applications. Applications that @@ -4466,10 +4758,7 @@ The following has been removed: function returns a 32-bit integer instead of a string. -A "simplified API" has been added (see documentation in png.h and a simple -example in contrib/examples/pngtopng.c) - -XII. Detecting libpng +XIII. Detecting libpng The png_get_io_ptr() function has been present since libpng-0.88, has never changed, and is unaffected by conditional compilation macros. It is the @@ -4478,7 +4767,7 @@ libpng version since 0.88. In an autoconf "configure.in" you could use AC_CHECK_LIB(png, png_get_io_ptr, ... -XIII. Source code repository +XV. Source code repository Since about February 2009, version 1.2.34, libpng has been under "git" source control. The git repository was built from old libpng-x.y.z.tar.gz files @@ -4502,7 +4791,7 @@ simple verbal discriptions of bug fixes, reported either to the SourceForge bug tracker, to the png-mng-implement at lists.sf.net mailing list, or directly to glennrp. -XIV. Coding style +XV. Coding style Our coding style is similar to the "Allman" style, with curly braces on separate lines: @@ -4614,9 +4903,9 @@ Lines do not exceed 80 characters. Other rules can be inferred by inspecting the libpng source. -XV. Y2K Compliance in libpng +XVI. Y2K Compliance in libpng -December 30, 2011 +January 11, 2012 Since the PNG Development group is an ad-hoc body, we can't make an official declaration. diff --git a/libpng.3 b/libpng.3 index 95443af69..5de93d700 100644 --- a/libpng.3 +++ b/libpng.3 @@ -1,997 +1,486 @@ -.TH LIBPNG 3 "December 30, 2011" +.TH LIBPNG 3 "January 11, 2012" .SH NAME libpng \- Portable Network Graphics (PNG) Reference Library 1.6.0beta05 .SH SYNOPSIS -\fI\fB - -\fB#include \fP - -\fI\fB +\fB +#include \fP \fBpng_uint_32 png_access_version_number \fI(void\fP\fB);\fP -\fI\fB - \fBvoid png_benign_error (png_structp \fP\fIpng_ptr\fP\fB, png_const_charp \fIerror\fP\fB);\fP -\fI\fB - \fBvoid png_build_grayscale_palette (int \fP\fIbit_depth\fP\fB, png_colorp \fIpalette\fP\fB);\fP -\fI\fB - \fBpng_voidp png_calloc (png_structp \fP\fIpng_ptr\fP\fB, png_alloc_size_t \fIsize\fP\fB);\fP -\fI\fB - \fBvoid png_chunk_benign_error (png_structp \fP\fIpng_ptr\fP\fB, png_const_charp \fIerror\fP\fB);\fP -\fI\fB - \fBvoid png_chunk_error (png_structp \fP\fIpng_ptr\fP\fB, png_const_charp \fIerror\fP\fB);\fP -\fI\fB - \fBvoid png_chunk_warning (png_structp \fP\fIpng_ptr\fP\fB, png_const_charp \fImessage\fP\fB);\fP -\fI\fB - \fBvoid png_convert_from_struct_tm (png_timep \fP\fIptime\fP\fB, struct tm FAR * \fIttime\fP\fB);\fP -\fI\fB - \fBvoid png_convert_from_time_t (png_timep \fP\fIptime\fP\fB, time_t \fIttime\fP\fB);\fP -\fI\fB - \fBpng_charp png_convert_to_rfc1123 (png_structp \fP\fIpng_ptr\fP\fB, png_timep \fIptime\fP\fB);\fP -\fI\fB - \fBpng_infop png_create_info_struct (png_structp \fIpng_ptr\fP\fB);\fP -\fI\fB - \fBpng_structp png_create_read_struct (png_const_charp \fP\fIuser_png_ver\fP\fB, png_voidp \fP\fIerror_ptr\fP\fB, png_error_ptr \fP\fIerror_fn\fP\fB, png_error_ptr \fIwarn_fn\fP\fB);\fP -\fI\fB - \fBpng_structp png_create_read_struct_2 (png_const_charp \fP\fIuser_png_ver\fP\fB, png_voidp \fP\fIerror_ptr\fP\fB, png_error_ptr \fP\fIerror_fn\fP\fB, png_error_ptr \fP\fIwarn_fn\fP\fB, png_voidp \fP\fImem_ptr\fP\fB, png_malloc_ptr \fP\fImalloc_fn\fP\fB, png_free_ptr \fIfree_fn\fP\fB);\fP -\fI\fB - \fBpng_structp png_create_write_struct (png_const_charp \fP\fIuser_png_ver\fP\fB, png_voidp \fP\fIerror_ptr\fP\fB, png_error_ptr \fP\fIerror_fn\fP\fB, png_error_ptr \fIwarn_fn\fP\fB);\fP -\fI\fB - \fBpng_structp png_create_write_struct_2 (png_const_charp \fP\fIuser_png_ver\fP\fB, png_voidp \fP\fIerror_ptr\fP\fB, png_error_ptr \fP\fIerror_fn\fP\fB, png_error_ptr \fP\fIwarn_fn\fP\fB, png_voidp \fP\fImem_ptr\fP\fB, png_malloc_ptr \fP\fImalloc_fn\fP\fB, png_free_ptr \fIfree_fn\fP\fB);\fP -\fI\fB - \fBvoid png_data_freer (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, int \fP\fIfreer\fP\fB, png_uint_32 \fImask)\fP\fB);\fP -\fI\fB - \fBvoid png_destroy_info_struct (png_structp \fP\fIpng_ptr\fP\fB, png_infopp \fIinfo_ptr_ptr\fP\fB);\fP -\fI\fB - \fBvoid png_destroy_read_struct (png_structpp \fP\fIpng_ptr_ptr\fP\fB, png_infopp \fP\fIinfo_ptr_ptr\fP\fB, png_infopp \fIend_info_ptr_ptr\fP\fB);\fP -\fI\fB - \fBvoid png_destroy_write_struct (png_structpp \fP\fIpng_ptr_ptr\fP\fB, png_infopp \fIinfo_ptr_ptr\fP\fB);\fP -\fI\fB - \fBvoid png_err (png_structp \fIpng_ptr\fP\fB);\fP -\fI\fB - \fBvoid png_error (png_structp \fP\fIpng_ptr\fP\fB, png_const_charp \fIerror\fP\fB);\fP -\fI\fB - \fBvoid png_free (png_structp \fP\fIpng_ptr\fP\fB, png_voidp \fIptr\fP\fB);\fP -\fI\fB - \fBvoid png_free_chunk_list (png_structp \fIpng_ptr\fP\fB);\fP -\fI\fB - \fBvoid png_free_default (png_structp \fP\fIpng_ptr\fP\fB, png_voidp \fIptr\fP\fB);\fP -\fI\fB - \fBvoid png_free_data (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, int \fInum\fP\fB);\fP -\fI\fB - \fBpng_byte png_get_bit_depth (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fIinfo_ptr\fP\fB);\fP -\fI\fB - \fBpng_uint_32 png_get_bKGD (png_const_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_color_16p \fI*background\fP\fB);\fP -\fI\fB - \fBpng_byte png_get_channels (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fIinfo_ptr\fP\fB);\fP -\fI\fB - \fBpng_uint_32 png_get_cHRM (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fP\fIinfo_ptr\fP\fB, double \fP\fI*white_x\fP\fB, double \fP\fI*white_y\fP\fB, double \fP\fI*red_x\fP\fB, double \fP\fI*red_y\fP\fB, double \fP\fI*green_x\fP\fB, double \fP\fI*green_y\fP\fB, double \fP\fI*blue_x\fP\fB, double \fI*blue_y\fP\fB);\fP -\fI\fB - \fBpng_uint_32 png_get_cHRM_fixed (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fP\fI*white_x\fP\fB, png_uint_32 \fP\fI*white_y\fP\fB, png_uint_32 \fP\fI*red_x\fP\fB, png_uint_32 \fP\fI*red_y\fP\fB, png_uint_32 \fP\fI*green_x\fP\fB, png_uint_32 \fP\fI*green_y\fP\fB, png_uint_32 \fP\fI*blue_x\fP\fB, png_uint_32 \fI*blue_y\fP\fB);\fP -\fI\fB - -\fBpng_uint_32 png_get_cHRM_XYZ (png_structp \fIpng_ptr, - -\fBpng_const_infop \fP\fIinfo_ptr\fP\fB, double \fP\fI*red_X\fP\fB, double \fP\fI*red_Y\fP\fB, double \fI*red_Z, - -\fBdouble \fP\fI*green_X\fP\fB, double \fP\fI*green_Y\fP\fB, double \fP\fI*green_Z\fP\fB, double \fI*blue_X, - -\fBdouble \fP\fI*blue_Y\fP\fB, double \fI*blue_Z\fP\fB);\fP - -\fI\fB +\fBpng_uint_32 png_get_cHRM_XYZ (png_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fP\fIinfo_ptr\fP\fB, double \fP\fI*red_X\fP\fB, double \fP\fI*red_Y\fP\fB, double \fP\fI*red_Z\fP\fB, double \fP\fI*green_X\fP\fB, double \fP\fI*green_Y\fP\fB, double \fP\fI*green_Z\fP\fB, double \fP\fI*blue_X\fP\fB, double \fP\fI*blue_Y\fP\fB, double \fI*blue_Z\fP\fB);\fP \fBpng_uint_32 png_get_cHRM_XYZ_fixed (png_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fP\fIinfo_ptr\fP\fB, png_fixed_point \fP\fI*int_red_X\fP\fB, png_fixed_point \fP\fI*int_red_Y\fP\fB, png_fixed_point \fP\fI*int_red_Z\fP\fB, png_fixed_point \fP\fI*int_green_X\fP\fB, png_fixed_point \fP\fI*int_green_Y\fP\fB, png_fixed_point \fP\fI*int_green_Z\fP\fB, png_fixed_point \fP\fI*int_blue_X\fP\fB, png_fixed_point \fP\fI*int_blue_Y\fP\fB, png_fixed_point \fI*int_blue_Z\fP\fB);\fP -\fI\fB - \fBpng_uint_32 png_get_chunk_cache_max (png_const_structp \fIpng_ptr\fP\fB);\fP -\fI\fB - \fBpng_alloc_size_t png_get_chunk_malloc_max (png_const_structp \fIpng_ptr\fP\fB);\fP -\fI\fB - \fBpng_byte png_get_color_type (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fIinfo_ptr\fP\fB);\fP -\fI\fB - \fBpng_uint_32 png_get_compression_buffer_size (png_const_structp \fIpng_ptr\fP\fB);\fP -\fI\fB - \fBpng_byte png_get_compression_type (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fIinfo_ptr\fP\fB);\fP -\fI\fB - \fBpng_byte png_get_copyright (png_const_structp \fIpng_ptr\fP\fB);\fP -\fI\fB - \fBpng_uint_32 png_get_current_row_number \fI(png_const_structp\fP\fB);\fP -\fI\fB - \fBpng_byte png_get_current_pass_number \fI(png_const_structp\fP\fB);\fP -\fI\fB - \fBpng_voidp png_get_error_ptr (png_const_structp \fIpng_ptr\fP\fB);\fP -\fI\fB - \fBpng_byte png_get_filter_type (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fIinfo_ptr\fP\fB);\fP -\fI\fB - \fBpng_uint_32 png_get_gAMA (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fP\fIinfo_ptr\fP\fB, double \fI*file_gamma\fP\fB);\fP -\fI\fB - \fBpng_uint_32 png_get_gAMA_fixed (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fI*int_file_gamma\fP\fB);\fP -\fI\fB - \fBpng_byte png_get_header_ver (png_const_structp \fIpng_ptr\fP\fB);\fP -\fI\fB - \fBpng_byte png_get_header_version (png_const_structp \fIpng_ptr\fP\fB);\fP -\fI\fB - \fBpng_uint_32 png_get_hIST (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fP\fIinfo_ptr\fP\fB, png_uint_16p \fI*hist\fP\fB);\fP -\fI\fB - \fBpng_uint_32 png_get_iCCP (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fP\fIinfo_ptr\fP\fB, png_charpp \fP\fIname\fP\fB, int \fP\fI*compression_type\fP\fB, png_bytepp \fP\fIprofile\fP\fB, png_uint_32 \fI*proflen\fP\fB);\fP -\fI\fB - \fBpng_uint_32 png_get_IHDR (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fP\fI*width\fP\fB, png_uint_32 \fP\fI*height\fP\fB, int \fP\fI*bit_depth\fP\fB, int \fP\fI*color_type\fP\fB, int \fP\fI*interlace_type\fP\fB, int \fP\fI*compression_type\fP\fB, int \fI*filter_type\fP\fB);\fP -\fI\fB - \fBpng_uint_32 png_get_image_height (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fIinfo_ptr\fP\fB);\fP -\fI\fB - \fBpng_uint_32 png_get_image_width (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fIinfo_ptr\fP\fB);\fP -\fI\fB - \fBpng_int_32 png_get_int_32 (png_bytep \fIbuf\fP\fB);\fP -\fI\fB - \fBpng_byte png_get_interlace_type (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fIinfo_ptr\fP\fB);\fP -\fI\fB - \fBpng_uint_32 png_get_io_chunk_type (png_const_structp \fIpng_ptr\fP\fB);\fP -\fI\fB - \fBpng_voidp png_get_io_ptr (png_structp \fIpng_ptr\fP\fB);\fP -\fI\fB - \fBpng_uint_32 png_get_io_state (png_structp \fIpng_ptr\fP\fB);\fP -\fI\fB - \fBpng_byte png_get_libpng_ver (png_const_structp \fIpng_ptr\fP\fB);\fP -\fI\fB - \fBpng_voidp png_get_mem_ptr (png_const_structp \fIpng_ptr\fP\fB);\fP -\fI\fB - \fBpng_uint_32 png_get_oFFs (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fP\fI*offset_x\fP\fB, png_uint_32 \fP\fI*offset_y\fP\fB, int \fI*unit_type\fP\fB);\fP -\fI\fB - \fBpng_uint_32 png_get_pCAL (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fP\fIinfo_ptr\fP\fB, png_charp \fP\fI*purpose\fP\fB, png_int_32 \fP\fI*X0\fP\fB, png_int_32 \fP\fI*X1\fP\fB, int \fP\fI*type\fP\fB, int \fP\fI*nparams\fP\fB, png_charp \fP\fI*units\fP\fB, png_charpp \fI*params\fP\fB);\fP -\fI\fB - \fBpng_uint_32 png_get_pHYs (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fP\fI*res_x\fP\fB, png_uint_32 \fP\fI*res_y\fP\fB, int \fI*unit_type\fP\fB);\fP -\fI\fB - \fBfloat png_get_pixel_aspect_ratio (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fIinfo_ptr\fP\fB);\fP -\fI\fB - \fBpng_uint_32 png_get_pHYs_dpi (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fP\fI*res_x\fP\fB, png_uint_32 \fP\fI*res_y\fP\fB, int \fI*unit_type\fP\fB);\fP -\fI\fB - \fBpng_fixed_point png_get_pixel_aspect_ratio_fixed (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fIinfo_ptr\fP\fB);\fP -\fI\fB - \fBpng_uint_32 png_get_pixels_per_inch (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fIinfo_ptr\fP\fB);\fP -\fI\fB - \fBpng_uint_32 png_get_pixels_per_meter (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fIinfo_ptr\fP\fB);\fP -\fI\fB - \fBpng_voidp png_get_progressive_ptr (png_const_structp \fIpng_ptr\fP\fB);\fP -\fI\fB - \fBpng_uint_32 png_get_PLTE (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fP\fIinfo_ptr\fP\fB, png_colorp \fP\fI*palette\fP\fB, int \fI*num_palette\fP\fB);\fP -\fI\fB - -\fBpng_byte png_get_rgb_to_gray_status (png_const_structp \fIpng_ptr) - -\fBpng_uint_32 png_get_rowbytes (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fIinfo_ptr\fP\fB);\fP - -\fI\fB +\fBpng_byte png_get_rgb_to_gray_status (png_const_structp png_ptr) png_uint_32 png_get_rowbytes (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fIinfo_ptr\fP\fB);\fP \fBpng_bytepp png_get_rows (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fIinfo_ptr\fP\fB);\fP -\fI\fB - \fBpng_uint_32 png_get_sBIT (png_const_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_color_8p \fI*sig_bit\fP\fB);\fP -\fI\fB - \fBvoid png_get_sCAL (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fP\fIinfo_ptr\fP\fB, int* \fP\fIunit\fP\fB, double* \fP\fIwidth\fP\fB, double* \fIheight\fP\fB);\fP -\fI\fB - \fBvoid png_get_sCAL_fixed (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fP\fIinfo_ptr\fP\fB, int* \fP\fIunit\fP\fB, png_fixed_pointp \fP\fIwidth\fP\fB, png_fixed_pointp \fIheight\fP\fB);\fP -\fI\fB - \fBvoid png_get_sCAL_s (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fP\fIinfo_ptr\fP\fB, int* \fP\fIunit\fP\fB, png_charpp \fP\fIwidth\fP\fB, png_charpp \fIheight\fP\fB);\fP -\fI\fB - \fBpng_bytep png_get_signature (png_const_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP -\fI\fB - \fBpng_uint_32 png_get_sPLT (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fP\fIinfo_ptr\fP\fB, png_spalette_p \fI*splt_ptr\fP\fB);\fP -\fI\fB - \fBpng_uint_32 png_get_sRGB (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fP\fIinfo_ptr\fP\fB, int \fI*file_srgb_intent\fP\fB);\fP -\fI\fB - \fBpng_uint_32 png_get_text (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fP\fIinfo_ptr\fP\fB, png_textp \fP\fI*text_ptr\fP\fB, int \fI*num_text\fP\fB);\fP -\fI\fB - \fBpng_uint_32 png_get_tIME (png_const_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_timep \fI*mod_time\fP\fB);\fP -\fI\fB - \fBpng_uint_32 png_get_tRNS (png_const_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_bytep \fP\fI*trans_alpha\fP\fB, int \fP\fI*num_trans\fP\fB, png_color_16p \fI*trans_color\fP\fB);\fP -\fI\fB - -\fB/* This function is really an inline macro. \fI*/ - -\fBpng_uint_16 png_get_uint_16 (png_bytep \fIbuf\fP\fB);\fP - -\fI\fB +\fB/* This function is really an inline macro. */ png_uint_16 png_get_uint_16 (png_bytep \fIbuf\fP\fB);\fP \fBpng_uint_32 png_get_uint_31 (png_structp \fP\fIpng_ptr\fP\fB, png_bytep \fIbuf\fP\fB);\fP -\fI\fB - -\fB/* This function is really an inline macro. \fI*/ - -\fBpng_uint_32 png_get_uint_32 (png_bytep \fIbuf\fP\fB);\fP - -\fI\fB +\fB/* This function is really an inline macro. */ png_uint_32 png_get_uint_32 (png_bytep \fIbuf\fP\fB);\fP \fBpng_uint_32 png_get_unknown_chunks (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fP\fIinfo_ptr\fP\fB, png_unknown_chunkpp \fIunknowns\fP\fB);\fP -\fI\fB - \fBpng_voidp png_get_user_chunk_ptr (png_const_structp \fIpng_ptr\fP\fB);\fP -\fI\fB - \fBpng_uint_32 png_get_user_height_max (png_const_structp \fIpng_ptr\fP\fB);\fP -\fI\fB - \fBpng_voidp png_get_user_transform_ptr (png_const_structp \fIpng_ptr\fP\fB);\fP -\fI\fB - \fBpng_uint_32 png_get_user_width_max (png_const_structp \fIpng_ptr\fP\fB);\fP -\fI\fB - \fBpng_uint_32 png_get_valid (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fIflag\fP\fB);\fP -\fI\fB - \fBfloat png_get_x_offset_inches (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fIinfo_ptr\fP\fB);\fP -\fI\fB - \fBpng_fixed_point png_get_x_offset_inches_fixed (png_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fIinfo_ptr\fP\fB);\fP -\fI\fB - \fBpng_int_32 png_get_x_offset_microns (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fIinfo_ptr\fP\fB);\fP -\fI\fB - \fBpng_int_32 png_get_x_offset_pixels (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fIinfo_ptr\fP\fB);\fP -\fI\fB - \fBpng_uint_32 png_get_x_pixels_per_inch (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fIinfo_ptr\fP\fB);\fP -\fI\fB - \fBpng_uint_32 png_get_x_pixels_per_meter (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fIinfo_ptr\fP\fB);\fP -\fI\fB - \fBfloat png_get_y_offset_inches (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fIinfo_ptr\fP\fB);\fP -\fI\fB - \fBpng_fixed_point png_get_y_offset_inches_fixed (png_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fIinfo_ptr\fP\fB);\fP -\fI\fB - \fBpng_int_32 png_get_y_offset_microns (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fIinfo_ptr\fP\fB);\fP -\fI\fB - \fBpng_int_32 png_get_y_offset_pixels (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fIinfo_ptr\fP\fB);\fP -\fI\fB - \fBpng_uint_32 png_get_y_pixels_per_inch (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fIinfo_ptr\fP\fB);\fP -\fI\fB - \fBpng_uint_32 png_get_y_pixels_per_meter (png_const_structp \fP\fIpng_ptr\fP\fB, png_const_infop \fIinfo_ptr\fP\fB);\fP -\fI\fB - \fBint png_handle_as_unknown (png_structp \fP\fIpng_ptr\fP\fB, png_bytep \fIchunk_name\fP\fB);\fP -\fI\fB - \fBint png_image_begin_read_from_file (png_imagep \fP\fIimage\fP\fB, const char \fI*file_name\fP\fB);\fP -\fI\fB - \fBint png_image_begin_read_from_stdio (png_imagep \fP\fIimage\fP\fB, FILE* \fIfile\fP\fB);\fP -\fI\fB - \fBint, png_image_begin_read_from_memory (png_imagep \fP\fIimage\fP\fB, png_const_voidp \fP\fImemory\fP\fB, png_size_t \fIsize\fP\fB);\fP -\fI\fB - \fBint png_image_finish_read (png_imagep \fP\fIimage\fP\fB, png_colorp \fP\fIbackground\fP\fB, void \fP\fI*buffer\fP\fB, png_int_32 \fIrow_stride\fP\fB);\fP -\fI\fB - \fBvoid png_image_free (png_imagep \fIimage\fP\fB);\fP -\fI\fB - -\fBint png_image_write_to_file (png_imagep \fP\fIimage\fP\fB, const char \fP\fI*file\fP\fB, int \fP\fIconvert_to_8bit\fP\fB, const void \fI*buffer, - -\fBpng_int_32 \fIrow_stride\fP\fB);\fP - -\fI\fB +\fBint png_image_write_to_file (png_imagep \fP\fIimage\fP\fB, const char \fP\fI*file\fP\fB, int \fP\fIconvert_to_8bit\fP\fB, const void \fP\fI*buffer\fP\fB, png_int_32 \fIrow_stride\fP\fB);\fP \fBint png_image_write_to_stdio (png_imagep \fP\fIimage\fP\fB, FILE \fP\fI*file\fP\fB, int \fP\fIconvert_to_8_bit\fP\fB, const void \fP\fI*buffer\fP\fB, png_int_32 \fIrow_stride)\fP\fB);\fP -\fI\fB - \fBvoid png_info_init_3 (png_infopp \fP\fIinfo_ptr\fP\fB, png_size_t \fIpng_info_struct_size\fP\fB);\fP -\fI\fB - \fBvoid png_init_io (png_structp \fP\fIpng_ptr\fP\fB, FILE \fI*fp\fP\fB);\fP -\fI\fB - \fBvoid png_longjmp (png_structp \fP\fIpng_ptr\fP\fB, int \fIval\fP\fB);\fP -\fI\fB - \fBpng_voidp png_malloc (png_structp \fP\fIpng_ptr\fP\fB, png_alloc_size_t \fIsize\fP\fB);\fP -\fI\fB - \fBpng_voidp png_malloc_default (png_structp \fP\fIpng_ptr\fP\fB, png_alloc_size_t \fIsize\fP\fB);\fP -\fI\fB - \fBpng_voidp png_malloc_warn (png_structp \fP\fIpng_ptr\fP\fB, png_alloc_size_t \fIsize\fP\fB);\fP -\fI\fB - \fBpng_uint_32 png_permit_mng_features (png_structp \fP\fIpng_ptr\fP\fB, png_uint_32 \fImng_features_permitted\fP\fB);\fP -\fI\fB - \fBvoid png_process_data (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_bytep \fP\fIbuffer\fP\fB, png_size_t \fIbuffer_size\fP\fB);\fP -\fI\fB - \fBpng_size_t png_process_data_pause \fP\fI(png_structp\fP\fB, int \fIsave\fP\fB);\fP -\fI\fB - \fBpng_uint_32 png_process_data_skip \fI(png_structp\fP\fB);\fP -\fI\fB - \fBvoid png_progressive_combine_row (png_structp \fP\fIpng_ptr\fP\fB, png_bytep \fP\fIold_row\fP\fB, png_bytep \fInew_row\fP\fB);\fP -\fI\fB - \fBvoid png_read_end (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP -\fI\fB - \fBvoid png_read_image (png_structp \fP\fIpng_ptr\fP\fB, png_bytepp \fIimage\fP\fB);\fP -\fI\fB - \fBvoid png_read_info (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP -\fI\fB - \fBvoid png_read_png (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, int \fP\fItransforms\fP\fB, png_voidp \fIparams\fP\fB);\fP -\fI\fB - \fBvoid png_read_row (png_structp \fP\fIpng_ptr\fP\fB, png_bytep \fP\fIrow\fP\fB, png_bytep \fIdisplay_row\fP\fB);\fP -\fI\fB - \fBvoid png_read_rows (png_structp \fP\fIpng_ptr\fP\fB, png_bytepp \fP\fIrow\fP\fB, png_bytepp \fP\fIdisplay_row\fP\fB, png_uint_32 \fInum_rows\fP\fB);\fP -\fI\fB - \fBvoid png_read_update_info (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP -\fI\fB - \fBint png_reset_zstream (png_structp \fIpng_ptr\fP\fB);\fP -\fI\fB - \fBvoid png_save_int_32 (png_bytep \fP\fIbuf\fP\fB, png_int_32 \fIi\fP\fB);\fP -\fI\fB - \fBvoid png_save_uint_16 (png_bytep \fP\fIbuf\fP\fB, unsigned int \fIi\fP\fB);\fP -\fI\fB - \fBvoid png_save_uint_32 (png_bytep \fP\fIbuf\fP\fB, png_uint_32 \fIi\fP\fB);\fP -\fI\fB - -\fBvoid png_set_add_alpha (png_structp \fP\fIpng_ptr\fP\fB, png_uint_32 \fP\fIfiller\fP\fB, int \fIflags\fP\fB);\fP - -\fI\fB - -\fBvoid png_set_alpha_mode (png_structp \fP\fIpng_ptr\fP\fB, int \fP\fImode\fP\fB, double \fIoutput_gamma\fP\fB);\fP - -\fI\fB - -\fBvoid png_set_alpha_mode_fixed (png_structp \fP\fIpng_ptr\fP\fB, int \fP\fImode\fP\fB, png_fixed_point \fIoutput_gamma\fP\fB);\fP - -\fI\fB +\fBvoid png_set_add_alpha (png_structp \fP\fIpng_ptr\fP\fB, png_uint_32 \fP\fIfiller\fP\fB, int flags); void png_set_alpha_mode (png_structp \fP\fIpng_ptr\fP\fB, int \fP\fImode\fP\fB, double output_gamma); void png_set_alpha_mode_fixed (png_structp \fP\fIpng_ptr\fP\fB, int \fP\fImode\fP\fB, png_fixed_point \fIoutput_gamma\fP\fB);\fP \fBvoid png_set_background (png_structp \fP\fIpng_ptr\fP\fB, png_color_16p \fP\fIbackground_color\fP\fB, int \fP\fIbackground_gamma_code\fP\fB, int \fP\fIneed_expand\fP\fB, double \fIbackground_gamma\fP\fB);\fP -\fI\fB - \fBvoid png_set_background_fixed (png_structp \fP\fIpng_ptr\fP\fB, png_color_16p \fP\fIbackground_color\fP\fB, int \fP\fIbackground_gamma_code\fP\fB, int \fP\fIneed_expand\fP\fB, png_uint_32 \fIbackground_gamma\fP\fB);\fP -\fI\fB - \fBvoid png_set_benign_errors (png_structp \fP\fIpng_ptr\fP\fB, int \fIallowed\fP\fB);\fP -\fI\fB - \fBvoid png_set_bgr (png_structp \fIpng_ptr\fP\fB);\fP -\fI\fB - \fBvoid png_set_bKGD (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_color_16p \fIbackground\fP\fB);\fP -\fI\fB - \fBvoid png_set_cHRM (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, double \fP\fIwhite_x\fP\fB, double \fP\fIwhite_y\fP\fB, double \fP\fIred_x\fP\fB, double \fP\fIred_y\fP\fB, double \fP\fIgreen_x\fP\fB, double \fP\fIgreen_y\fP\fB, double \fP\fIblue_x\fP\fB, double \fIblue_y\fP\fB);\fP -\fI\fB - \fBvoid png_set_cHRM_fixed (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fP\fIwhite_x\fP\fB, png_uint_32 \fP\fIwhite_y\fP\fB, png_uint_32 \fP\fIred_x\fP\fB, png_uint_32 \fP\fIred_y\fP\fB, png_uint_32 \fP\fIgreen_x\fP\fB, png_uint_32 \fP\fIgreen_y\fP\fB, png_uint_32 \fP\fIblue_x\fP\fB, png_uint_32 \fIblue_y\fP\fB);\fP -\fI\fB - -\fBvoid png_set_cHRM_XYZ (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, double \fP\fIred_X\fP\fB, double \fP\fIred_Y\fP\fB, double \fP\fIred_Z\fP\fB, double \fP\fIgreen_X\fP\fB, double \fIgreen_Y, - -\fBdouble \fP\fIgreen_Z\fP\fB, double \fP\fIblue_X\fP\fB, double \fP\fIblue_Y\fP\fB, double \fIblue_Z\fP\fB);\fP - -\fI\fB +\fBvoid png_set_cHRM_XYZ (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, double \fP\fIred_X\fP\fB, double \fP\fIred_Y\fP\fB, double \fP\fIred_Z\fP\fB, double \fP\fIgreen_X\fP\fB, double \fP\fIgreen_Y\fP\fB, double \fP\fIgreen_Z\fP\fB, double \fP\fIblue_X\fP\fB, double \fP\fIblue_Y\fP\fB, double \fIblue_Z\fP\fB);\fP \fBvoid png_set_cHRM_XYZ_fixed (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_fixed_point \fP\fIint_red_X\fP\fB, png_fixed_point \fP\fIint_red_Y\fP\fB, png_fixed_point \fP\fIint_red_Z\fP\fB, png_fixed_point \fP\fIint_green_X\fP\fB, png_fixed_point \fP\fIint_green_Y\fP\fB, png_fixed_point \fP\fIint_green_Z\fP\fB, png_fixed_point \fP\fIint_blue_X\fP\fB, png_fixed_point \fP\fIint_blue_Y\fP\fB, png_fixed_point \fIint_blue_Z\fP\fB);\fP -\fI\fB - \fBvoid png_set_chunk_cache_max (png_structp \fP\fIpng_ptr\fP\fB, png_uint_32 \fIuser_chunk_cache_max\fP\fB);\fP -\fI\fB - \fBvoid png_set_compression_level (png_structp \fP\fIpng_ptr\fP\fB, int \fIlevel\fP\fB);\fP -\fI\fB - \fBvoid png_set_compression_mem_level (png_structp \fP\fIpng_ptr\fP\fB, int \fImem_level\fP\fB);\fP -\fI\fB - \fBvoid png_set_compression_method (png_structp \fP\fIpng_ptr\fP\fB, int \fImethod\fP\fB);\fP -\fI\fB - \fBvoid png_set_compression_strategy (png_structp \fP\fIpng_ptr\fP\fB, int \fIstrategy\fP\fB);\fP -\fI\fB - \fBvoid png_set_compression_window_bits (png_structp \fP\fIpng_ptr\fP\fB, int \fIwindow_bits\fP\fB);\fP -\fI\fB - \fBvoid png_set_crc_action (png_structp \fP\fIpng_ptr\fP\fB, int \fP\fIcrit_action\fP\fB, int \fIancil_action\fP\fB);\fP -\fI\fB - \fBvoid png_set_error_fn (png_structp \fP\fIpng_ptr\fP\fB, png_voidp \fP\fIerror_ptr\fP\fB, png_error_ptr \fP\fIerror_fn\fP\fB, png_error_ptr \fIwarning_fn\fP\fB);\fP -\fI\fB - \fBvoid png_set_expand (png_structp \fIpng_ptr\fP\fB);\fP -\fI\fB - \fBvoid png_set_expand_16 (png_structp \fIpng_ptr\fP\fB);\fP -\fI\fB - \fBvoid png_set_expand_gray_1_2_4_to_8 (png_structp \fIpng_ptr\fP\fB);\fP -\fI\fB - \fBvoid png_set_filler (png_structp \fP\fIpng_ptr\fP\fB, png_uint_32 \fP\fIfiller\fP\fB, int \fIflags\fP\fB);\fP -\fI\fB - \fBvoid png_set_filter (png_structp \fP\fIpng_ptr\fP\fB, int \fP\fImethod\fP\fB, int \fIfilters\fP\fB);\fP -\fI\fB - \fBvoid png_set_filter_heuristics (png_structp \fP\fIpng_ptr\fP\fB, int \fP\fIheuristic_method\fP\fB, int \fP\fInum_weights\fP\fB, png_doublep \fP\fIfilter_weights\fP\fB, png_doublep \fIfilter_costs\fP\fB);\fP -\fI\fB - \fBvoid png_set_filter_heuristics_fixed (png_structp \fP\fIpng_ptr\fP\fB, int \fP\fIheuristic_method\fP\fB, int \fP\fInum_weights\fP\fB, png_fixed_point_p \fP\fIfilter_weights\fP\fB, png_fixed_point_p \fIfilter_costs\fP\fB);\fP -\fI\fB - \fBvoid png_set_flush (png_structp \fP\fIpng_ptr\fP\fB, int \fInrows\fP\fB);\fP -\fI\fB - \fBvoid png_set_gamma (png_structp \fP\fIpng_ptr\fP\fB, double \fP\fIscreen_gamma\fP\fB, double \fIdefault_file_gamma\fP\fB);\fP -\fI\fB - -\fBvoid png_set_gamma_fixed (png_structp \fP\fIpng_ptr\fP\fB, png_uint_32 \fP\fIscreen_gamma\fP\fB, png_uint_32 \fIdefault_file_gamma\fP\fB);\fP - -\fI\fB - -\fBvoid png_set_gAMA (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, double \fIfile_gamma\fP\fB);\fP - -\fI\fB +\fBvoid png_set_gamma_fixed (png_structp \fP\fIpng_ptr\fP\fB, png_uint_32 \fP\fIscreen_gamma\fP\fB, png_uint_32 default_file_gamma); void png_set_gAMA (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, double \fIfile_gamma\fP\fB);\fP \fBvoid png_set_gAMA_fixed (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fIfile_gamma\fP\fB);\fP -\fI\fB - \fBvoid png_set_gray_1_2_4_to_8 (png_structp \fIpng_ptr\fP\fB);\fP -\fI\fB - \fBvoid png_set_gray_to_rgb (png_structp \fIpng_ptr\fP\fB);\fP -\fI\fB - \fBvoid png_set_hIST (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_16p \fIhist\fP\fB);\fP -\fI\fB - \fBvoid png_set_iCCP (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_const_charp \fP\fIname\fP\fB, int \fP\fIcompression_type\fP\fB, png_const_bytep \fP\fIprofile\fP\fB, png_uint_32 \fIproflen\fP\fB);\fP -\fI\fB - \fBint png_set_interlace_handling (png_structp \fIpng_ptr\fP\fB);\fP -\fI\fB - \fBvoid png_set_invalid (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, int \fImask\fP\fB);\fP -\fI\fB - \fBvoid png_set_invert_alpha (png_structp \fIpng_ptr\fP\fB);\fP -\fI\fB - \fBvoid png_set_invert_mono (png_structp \fIpng_ptr\fP\fB);\fP -\fI\fB - \fBvoid png_set_IHDR (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fP\fIwidth\fP\fB, png_uint_32 \fP\fIheight\fP\fB, int \fP\fIbit_depth\fP\fB, int \fP\fIcolor_type\fP\fB, int \fP\fIinterlace_type\fP\fB, int \fP\fIcompression_type\fP\fB, int \fIfilter_type\fP\fB);\fP -\fI\fB - \fBvoid png_set_keep_unknown_chunks (png_structp \fP\fIpng_ptr\fP\fB, int \fP\fIkeep\fP\fB, png_bytep \fP\fIchunk_list\fP\fB, int \fInum_chunks\fP\fB);\fP -\fI\fB - \fBjmp_buf* png_set_longjmp_fn (png_structp \fP\fIpng_ptr\fP\fB, png_longjmp_ptr \fP\fIlongjmp_fn\fP\fB, size_t \fIjmp_buf_size\fP\fB);\fP -\fI\fB - \fBvoid png_set_chunk_malloc_max (png_structp \fP\fIpng_ptr\fP\fB, png_alloc_size_t \fIuser_chunk_cache_max\fP\fB);\fP -\fI\fB - \fBvoid png_set_compression_buffer_size (png_structp \fP\fIpng_ptr\fP\fB, png_uint_32 \fIsize\fP\fB);\fP -\fI\fB - \fBvoid png_set_mem_fn (png_structp \fP\fIpng_ptr\fP\fB, png_voidp \fP\fImem_ptr\fP\fB, png_malloc_ptr \fP\fImalloc_fn\fP\fB, png_free_ptr \fIfree_fn\fP\fB);\fP -\fI\fB - \fBvoid png_set_oFFs (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fP\fIoffset_x\fP\fB, png_uint_32 \fP\fIoffset_y\fP\fB, int \fIunit_type\fP\fB);\fP -\fI\fB - \fBvoid png_set_packing (png_structp \fIpng_ptr\fP\fB);\fP -\fI\fB - \fBvoid png_set_packswap (png_structp \fIpng_ptr\fP\fB);\fP -\fI\fB - \fBvoid png_set_palette_to_rgb (png_structp \fIpng_ptr\fP\fB);\fP -\fI\fB - \fBvoid png_set_pCAL (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_charp \fP\fIpurpose\fP\fB, png_int_32 \fP\fIX0\fP\fB, png_int_32 \fP\fIX1\fP\fB, int \fP\fItype\fP\fB, int \fP\fInparams\fP\fB, png_charp \fP\fIunits\fP\fB, png_charpp \fIparams\fP\fB);\fP -\fI\fB - \fBvoid png_set_pHYs (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_uint_32 \fP\fIres_x\fP\fB, png_uint_32 \fP\fIres_y\fP\fB, int \fIunit_type\fP\fB);\fP -\fI\fB - \fBvoid png_set_progressive_read_fn (png_structp \fP\fIpng_ptr\fP\fB, png_voidp \fP\fIprogressive_ptr\fP\fB, png_progressive_info_ptr \fP\fIinfo_fn\fP\fB, png_progressive_row_ptr \fP\fIrow_fn\fP\fB, png_progressive_end_ptr \fIend_fn\fP\fB);\fP -\fI\fB - \fBvoid png_set_PLTE (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_colorp \fP\fIpalette\fP\fB, int \fInum_palette\fP\fB);\fP -\fI\fB - \fBvoid png_set_quantize (png_structp \fP\fIpng_ptr\fP\fB, png_colorp \fP\fIpalette\fP\fB, int \fP\fInum_palette\fP\fB, int \fP\fImaximum_colors\fP\fB, png_uint_16p \fP\fIhistogram\fP\fB, int \fIfull_quantize\fP\fB);\fP -\fI\fB - \fBvoid png_set_read_fn (png_structp \fP\fIpng_ptr\fP\fB, png_voidp \fP\fIio_ptr\fP\fB, png_rw_ptr \fIread_data_fn\fP\fB);\fP -\fI\fB - \fBvoid png_set_read_status_fn (png_structp \fP\fIpng_ptr\fP\fB, png_read_status_ptr \fIread_row_fn\fP\fB);\fP -\fI\fB - \fBvoid png_set_read_user_chunk_fn (png_structp \fP\fIpng_ptr\fP\fB, png_voidp \fP\fIuser_chunk_ptr\fP\fB, png_user_chunk_ptr \fIread_user_chunk_fn\fP\fB);\fP -\fI\fB - \fBvoid png_set_read_user_transform_fn (png_structp \fP\fIpng_ptr\fP\fB, png_user_transform_ptr \fIread_user_transform_fn\fP\fB);\fP -\fI\fB - \fBvoid png_set_rgb_to_gray (png_structp \fP\fIpng_ptr\fP\fB, int \fP\fIerror_action\fP\fB, double \fP\fIred\fP\fB, double \fIgreen\fP\fB);\fP -\fI\fB - \fBvoid png_set_rgb_to_gray_fixed (png_structp \fP\fIpng_ptr\fP\fB, int error_action png_uint_32 \fP\fIred\fP\fB, png_uint_32 \fIgreen\fP\fB);\fP -\fI\fB - \fBvoid png_set_rows (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_bytepp \fIrow_pointers\fP\fB);\fP -\fI\fB - \fBvoid png_set_sBIT (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_color_8p \fIsig_bit\fP\fB);\fP -\fI\fB - \fBvoid png_set_sCAL (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, int \fP\fIunit\fP\fB, double \fP\fIwidth\fP\fB, double \fIheight\fP\fB);\fP -\fI\fB - \fBvoid png_set_sCAL_fixed (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, int \fP\fIunit\fP\fB, png_fixed_point \fP\fIwidth\fP\fB, png_fixed_point \fIheight\fP\fB);\fP -\fI\fB - -\fBvoid png_set_sCAL_s (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, int \fP\fIunit\fP\fB, png_charp \fP\fIwidth\fP\fB, png_charp \fIheight\fP\fB);\fP - -\fI\fB - -\fBvoid png_set_scale_16 (png_structp \fIpng_ptr\fP\fB);\fP - -\fI\fB +\fBvoid png_set_sCAL_s (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, int \fP\fIunit\fP\fB, png_charp \fP\fIwidth\fP\fB, png_charp height); void png_set_scale_16 (png_structp \fIpng_ptr\fP\fB);\fP \fBvoid png_set_shift (png_structp \fP\fIpng_ptr\fP\fB, png_color_8p \fItrue_bits\fP\fB);\fP -\fI\fB - \fBvoid png_set_sig_bytes (png_structp \fP\fIpng_ptr\fP\fB, int \fInum_bytes\fP\fB);\fP -\fI\fB - \fBvoid png_set_sPLT (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_spalette_p \fP\fIsplt_ptr\fP\fB, int \fInum_spalettes\fP\fB);\fP -\fI\fB - \fBvoid png_set_sRGB (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, int \fIsrgb_intent\fP\fB);\fP -\fI\fB - \fBvoid png_set_sRGB_gAMA_and_cHRM (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, int \fIsrgb_intent\fP\fB);\fP -\fI\fB - \fBvoid png_set_strip_16 (png_structp \fIpng_ptr\fP\fB);\fP -\fI\fB - \fBvoid png_set_strip_alpha (png_structp \fIpng_ptr\fP\fB);\fP -\fI\fB - \fBvoid png_set_strip_error_numbers (png_structp \fP\fIpng_ptr\fP\fB, png_uint_32 \fIstrip_mode\fP\fB);\fP -\fI\fB - \fBvoid png_set_swap (png_structp \fIpng_ptr\fP\fB);\fP -\fI\fB - \fBvoid png_set_swap_alpha (png_structp \fIpng_ptr\fP\fB);\fP -\fI\fB - \fBvoid png_set_text (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_textp \fP\fItext_ptr\fP\fB, int \fInum_text\fP\fB);\fP -\fI\fB - \fBvoid png_set_text_compression_level (png_structp \fP\fIpng_ptr\fP\fB, int \fIlevel\fP\fB);\fP -\fI\fB - \fBvoid png_set_text_compression_mem_level (png_structp \fP\fIpng_ptr\fP\fB, int \fImem_level\fP\fB);\fP -\fI\fB - \fBvoid png_set_text_compression_strategy (png_structp \fP\fIpng_ptr\fP\fB, int \fIstrategy\fP\fB);\fP -\fI\fB - \fBvoid png_set_text_compression_window_bits (png_structp \fP\fIpng_ptr\fP\fB, int \fIwindow_bits\fP\fB);\fP -\fI\fB - \fBvoid \fP\fIpng_set_text_compression_method\fP\fB, (png_structp \fP\fIpng_ptr\fP\fB, int \fImethod)\fP\fB);\fP -\fI\fB - \fBvoid png_set_tIME (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_timep \fImod_time\fP\fB);\fP -\fI\fB - \fBvoid png_set_tRNS (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_bytep \fP\fItrans_alpha\fP\fB, int \fP\fInum_trans\fP\fB, png_color_16p \fItrans_color\fP\fB);\fP -\fI\fB - \fBvoid png_set_tRNS_to_alpha (png_structp \fIpng_ptr\fP\fB);\fP -\fI\fB - \fBpng_uint_32 png_set_unknown_chunks (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, png_unknown_chunkp \fP\fIunknowns\fP\fB, int \fP\fInum\fP\fB, int \fIlocation\fP\fB);\fP -\fI\fB - \fBvoid png_set_unknown_chunk_location (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, int \fP\fIchunk\fP\fB, int \fIlocation\fP\fB);\fP -\fI\fB - \fBvoid png_set_user_limits (png_structp \fP\fIpng_ptr\fP\fB, png_uint_32 \fP\fIuser_width_max\fP\fB, png_uint_32 \fIuser_height_max\fP\fB);\fP -\fI\fB - \fBvoid png_set_user_transform_info (png_structp \fP\fIpng_ptr\fP\fB, png_voidp \fP\fIuser_transform_ptr\fP\fB, int \fP\fIuser_transform_depth\fP\fB, int \fIuser_transform_channels\fP\fB);\fP -\fI\fB - \fBvoid png_set_write_fn (png_structp \fP\fIpng_ptr\fP\fB, png_voidp \fP\fIio_ptr\fP\fB, png_rw_ptr \fP\fIwrite_data_fn\fP\fB, png_flush_ptr \fIoutput_flush_fn\fP\fB);\fP -\fI\fB - \fBvoid png_set_write_status_fn (png_structp \fP\fIpng_ptr\fP\fB, png_write_status_ptr \fIwrite_row_fn\fP\fB);\fP -\fI\fB - \fBvoid png_set_write_user_transform_fn (png_structp \fP\fIpng_ptr\fP\fB, png_user_transform_ptr \fIwrite_user_transform_fn\fP\fB);\fP -\fI\fB - \fBint png_sig_cmp (png_bytep \fP\fIsig\fP\fB, png_size_t \fP\fIstart\fP\fB, png_size_t \fInum_to_check\fP\fB);\fP -\fI\fB - \fBvoid png_start_read_image (png_structp \fIpng_ptr\fP\fB);\fP -\fI\fB - \fBvoid png_warning (png_structp \fP\fIpng_ptr\fP\fB, png_const_charp \fImessage\fP\fB);\fP -\fI\fB - \fBvoid png_write_chunk (png_structp \fP\fIpng_ptr\fP\fB, png_bytep \fP\fIchunk_name\fP\fB, png_bytep \fP\fIdata\fP\fB, png_size_t \fIlength\fP\fB);\fP -\fI\fB - \fBvoid png_write_chunk_data (png_structp \fP\fIpng_ptr\fP\fB, png_bytep \fP\fIdata\fP\fB, png_size_t \fIlength\fP\fB);\fP -\fI\fB - \fBvoid png_write_chunk_end (png_structp \fIpng_ptr\fP\fB);\fP -\fI\fB - \fBvoid png_write_chunk_start (png_structp \fP\fIpng_ptr\fP\fB, png_bytep \fP\fIchunk_name\fP\fB, png_uint_32 \fIlength\fP\fB);\fP -\fI\fB - \fBvoid png_write_end (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP -\fI\fB - \fBvoid png_write_flush (png_structp \fIpng_ptr\fP\fB);\fP -\fI\fB - \fBvoid png_write_image (png_structp \fP\fIpng_ptr\fP\fB, png_bytepp \fIimage\fP\fB);\fP -\fI\fB - \fBvoid png_write_info (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP -\fI\fB - \fBvoid png_write_info_before_PLTE (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fIinfo_ptr\fP\fB);\fP -\fI\fB - \fBvoid png_write_png (png_structp \fP\fIpng_ptr\fP\fB, png_infop \fP\fIinfo_ptr\fP\fB, int \fP\fItransforms\fP\fB, png_voidp \fIparams\fP\fB);\fP -\fI\fB - \fBvoid png_write_row (png_structp \fP\fIpng_ptr\fP\fB, png_bytep \fIrow\fP\fB);\fP -\fI\fB - \fBvoid png_write_rows (png_structp \fP\fIpng_ptr\fP\fB, png_bytepp \fP\fIrow\fP\fB, png_uint_32 \fInum_rows\fP\fB);\fP -\fI\fB - \fBvoid png_write_sig (png_structp \fIpng_ptr\fP\fB);\fP -\fI\fB - \fBvoidpf png_zalloc (voidpf \fP\fIpng_ptr\fP\fB, uInt \fP\fIitems\fP\fB, uInt \fIsize\fP\fB);\fP -\fI\fB - \fBvoid png_zfree (voidpf \fP\fIpng_ptr\fP\fB, voidpf \fIptr\fP\fB);\fP -\fI\fB - .SH DESCRIPTION The .I libpng @@ -1003,7 +492,7 @@ Following is a copy of the libpng-manual.txt file that accompanies libpng. .SH LIBPNG.TXT libpng-manual.txt - A description on how to use and modify libpng - libpng version 1.6.0beta05 - December 30, 2011 + libpng version 1.6.0beta05 - January 11, 2012 Updated and distributed by Glenn Randers-Pehrson Copyright (c) 1998-2011 Glenn Randers-Pehrson @@ -1014,7 +503,7 @@ libpng-manual.txt - A description on how to use and modify libpng Based on: - libpng versions 0.97, January 1998, through 1.6.0beta05 - December 30, 2011 + libpng versions 0.97, January 1998, through 1.6.0beta05 - January 11, 2012 Updated and distributed by Glenn Randers-Pehrson Copyright (c) 1998-2011 Glenn Randers-Pehrson @@ -1037,17 +526,18 @@ libpng-manual.txt - A description on how to use and modify libpng II. Structures III. Reading IV. Writing - V. Modifying/Customizing libpng - VI. MNG support - VII. Changes to Libpng from version 0.88 - VIII. Changes to Libpng from version 1.0.x to 1.2.x - IX. Changes to Libpng from version 1.0.x/1.2.x to 1.4.x - X. Changes to Libpng from version 1.4.x to 1.5.x - XI. Changes to Libpng from version 1.5.x to 1.6.x - XII. Detecting libpng - XIII. Source code repository - XIV. Coding style - XV. Y2K Compliance in libpng + V. Simplified API + VI. Modifying/Customizing libpng + VII. MNG support + VIII. Changes to Libpng from version 0.88 + IX. Changes to Libpng from version 1.0.x to 1.2.x + X. Changes to Libpng from version 1.0.x/1.2.x to 1.4.x + XI. Changes to Libpng from version 1.4.x to 1.5.x + XII. Changes to Libpng from version 1.5.x to 1.6.x + XIII. Detecting libpng + XIV. Source code repository + XV. Coding style + XVI. Y2K Compliance in libpng .SH I. Introduction @@ -1710,7 +1200,8 @@ assumes that the PNG data matches your system, to keep this default call: or you can use the fixed point equivalent: - png_set_gamma_fixed(png_ptr, PNG_FP_1*screen_gamma, PNG_FP_1/screen_gamma); + png_set_gamma_fixed(png_ptr, PNG_FP_1*screen_gamma, + PNG_FP_1/screen_gamma); If you don't know the gamma for your system it is probably 2.2 - a good approximation to the IEC standard for display systems (sRGB). If images are @@ -1722,12 +1213,15 @@ display driver, a few systems, including older Macs, change the response by default. As of 1.5.4 three special values are available to handle common situations: - PNG_DEFAULT_sRGB: Indicates that the system conforms to the IEC 61966-2-1 - standard. This matches almost all systems. - PNG_GAMMA_MAC_18: Indicates that the system is an older (pre Mac OS 10.6) - Apple Macintosh system with the default settings. - PNG_GAMMA_LINEAR: Just the fixed point value for 1.0 - indicates that the - system expects data with no gamma encoding. + PNG_DEFAULT_sRGB: Indicates that the system conforms to the + IEC 61966-2-1 standard. This matches almost + all systems. + PNG_GAMMA_MAC_18: Indicates that the system is an older + (pre Mac OS 10.6) Apple Macintosh system with + the default settings. + PNG_GAMMA_LINEAR: Just the fixed point value for 1.0 - indicates + that the system expects data with no gamma + encoding. You would use the linear (unencoded) value if you need to process the pixel values further because this avoids the need to decode and reencode each @@ -1744,11 +1238,11 @@ Libpng only supports composing onto a single color (using png_set_background; see below). Otherwise you must do the composition yourself and, in this case, you may need to call png_set_alpha_mode: -#if PNG_LIBPNG_VER >= 10504 - png_set_alpha_mode(png_ptr, mode, screen_gamma); -#else - png_set_gamma(png_ptr, screen_gamma, 1.0/screen_gamma); -#endif + #if PNG_LIBPNG_VER >= 10504 + png_set_alpha_mode(png_ptr, mode, screen_gamma); + #else + png_set_gamma(png_ptr, screen_gamma, 1.0/screen_gamma); + #endif The screen_gamma value is the same as the argument to png_set_gamma; however, how it affects the output depends on the mode. png_set_alpha_mode() sets the @@ -2168,27 +1662,32 @@ pointer into the info_ptr is returned for any complex types. int_file_gamma - 100,000 times the gamma at which the file is written - png_get_cHRM(png_ptr, info_ptr, &white_x, &white_y, &red_x, &red_y, - &green_x, &green_y, &blue_x, &blue_y) - png_get_cHRM_XYZ(png_ptr, info_ptr, &red_X, &red_Y, &red_Z, &green_X, - &green_Y, &green_Z, &blue_X, &blue_Y, &blue_Z) - png_get_cHRM_fixed(png_ptr, info_ptr, &int_white_x, &int_white_y, - &int_red_x, &int_red_y, &int_green_x, &int_green_y, - &int_blue_x, &int_blue_y) + png_get_cHRM(png_ptr, info_ptr, &white_x, &white_y, &red_x, + &red_y, &green_x, &green_y, &blue_x, &blue_y) + png_get_cHRM_XYZ(png_ptr, info_ptr, &red_X, &red_Y, &red_Z, + &green_X, &green_Y, &green_Z, &blue_X, &blue_Y, + &blue_Z) + png_get_cHRM_fixed(png_ptr, info_ptr, &int_white_x, + &int_white_y, &int_red_x, &int_red_y, + &int_green_x, &int_green_y, &int_blue_x, + &int_blue_y) png_get_cHRM_XYZ_fixed(png_ptr, info_ptr, &int_red_X, &int_red_Y, - &int_red_Z, &int_green_X, &int_green_Y, &int_green_Z, - &int_blue_X, &int_blue_Y, &int_blue_Z) + &int_red_Z, &int_green_X, &int_green_Y, + &int_green_Z, &int_blue_X, &int_blue_Y, + &int_blue_Z) {white,red,green,blue}_{x,y} - A color space encoding specified using the chromaticities - of the end points and the white point. (PNG_INFO_cHRM) + A color space encoding specified using the + chromaticities of the end points and the + white point. (PNG_INFO_cHRM) {red,green,blue}_{X,Y,Z} - A color space encoding specified using the encoding end - points - the CIE tristimulus specification of the intended - color of the red, green and blue channels in the PNG RGB - data. The white point is simply the sum of the three end - points. (PNG_INFO_cHRM) + A color space encoding specified using the + encoding end points - the CIE tristimulus + specification of the intended color of the red, + green and blue channels in the PNG RGB data. + The white point is simply the sum of the three + end points. (PNG_INFO_cHRM) png_get_sRGB(png_ptr, info_ptr, &srgb_intent); @@ -2592,17 +2091,19 @@ Within the matrix, "A" means the transformation is obtained by png_set_add_alpha(). "X" means the transformation is obtained by png_set_expand(). "1" means the transformation is obtained by - png_set_expand_gray_1_2_4_to_8() (and by png_set_expand() if there - is no transparency in the original or the final format). + png_set_expand_gray_1_2_4_to_8() (and by png_set_expand() + if there is no transparency in the original or the final + format). "C" means the transformation is obtained by png_set_gray_to_rgb(). "G" means the transformation is obtained by png_set_rgb_to_gray(). "P" means the transformation is obtained by png_set_expand_palette_to_rgb(). "p" means the transformation is obtained by png_set_packing(). "Q" means the transformation is obtained by png_set_quantize(). - "T" means the transformation is obtained by png_set_tRNS_to_alpha(). - "B" means the transformation is obtained by png_set_background(), or - png_strip_alpha(). + "T" means the transformation is obtained by + png_set_tRNS_to_alpha(). + "B" means the transformation is obtained by + png_set_background(), or png_strip_alpha(). When an entry has multiple transforms listed all are required to cause the right overall transformation. When two transforms are separated by a comma @@ -2687,8 +2188,8 @@ with alpha. if (color_type == PNG_COLOR_TYPE_RGB || color_type == PNG_COLOR_TYPE_RGB_ALPHA) - png_set_rgb_to_gray(png_ptr, error_action, double red_weight, - double green_weight); + png_set_rgb_to_gray(png_ptr, error_action, + double red_weight, double green_weight); error_action = 1: silently do the conversion @@ -2710,7 +2211,8 @@ with alpha. In the corresponding fixed point API the red_weight and green_weight values are simply scaled by 100,000: - png_set_rgb_to_gray(png_ptr, error_action, png_fixed_point red_weight, + png_set_rgb_to_gray(png_ptr, error_action, + png_fixed_point red_weight, png_fixed_point green_weight); If you have set error_action = 1 or 2, you can @@ -4453,7 +3955,283 @@ if you transfer responsibility for free'ing text_ptr from libpng to your application, your application must not separately free those members. For a more compact example of writing a PNG image, see the file example.c. -.SH V. Modifying/Customizing libpng +.SH V. Simplified API + +The simplified API, which became available in libpng-1.6.0, hides the details +of both libpng and the PNG file format itself. +It allows PNG files to be read into a very limited number of +in-memory bitmap formats or to be written from the same formats. If these +formats do not accomodate your needs then you can, and should, use the more +sophisticated APIs above - these support a wide variety of in-memory formats +and a wide variety of sophisticated transformations to those formats as well +as a wide variety of APIs to manipulate ancilliary information. + +To read a PNG file using the simplified API: + + 1) Declare a 'png_image' structure (see below) on the + stack and memset() it to all zero. + + 2) Call the appropriate png_image_begin_read... function. + + 3) Set the png_image 'format' member to the required + format and allocate a buffer for the image. + + 4) Call png_image_finish_read to read the image into + your buffer. + +There are no restrictions on the format of the PNG input itself; all valid +color types, bit depths, and interlace methods are acceptable, and the +input image is transformed as necessary to the requested in-memory format +during the png_image_finish_read() step. + +To write a PNG file using the simplified API: + + 1) Declare a 'png_image' structure on the stack and memset() + it to all zero. + + 2) Initialize the members of the structure that describe the + image, setting the 'format' member to the format of the + image in memory. + + 3) Call the appropriate png_image_write... function with a + pointer to the image to write the PNG data. + +png_image is a structure that describes the in-memory format of an image +when it is being read or define the in-memory format of an image that you +need to write. The "png_image" structure contains the following members: + + png_uint_32 width Image width in pixels (columns) + png_uint_32 height Image height in pixels (rows) + png_uint_32 format Image format as defined below + png_uint_32 flags A bit mask containing informational flags + png_controlp opaque Initialize to NULL, free with png_image_free + +In the event of an error or warning the following field will be set to a +non-zero value and the 'message' field will contain a '\0' terminated +string with the libpng error or warning message. If both warnings and +an error were encountered, only the error is recorded. If there +are multiple warnings, only the first one is recorded. + +As of libpng-1.6.0 the values are + 0 - no warning or error + 1 - error + 2 - warning + + png_uint_32 warning_or_error; + char message[64]; + +The pixels (samples) of the image have one to four channels whose components +have original values in the range 0 to 1.0: + + 1: A single gray or luminance channel (G). + 2: A gray/luminance channel and an alpha channel (GA). + 3: Three red, green, blue color channels (RGB). + 4: Three color channels and an alpha channel (RGBA). + +The channels are encoded in one of two ways: + + a) As a small integer, value 0..255, contained in a (png_byte). For the +alpha channel the original value is simply value/255. For the color or +luminance channels the value is encoded according to the sRGB specification +and matches the 8-bit format expected by typical display devices. + +The color/gray channels are not scaled (pre-multiplied) by the alpha +channel and are suitable for passing to color management software. + + b) As a value in the range 0..65535, contained in a (png_uint_16). All +channels can be converted to the original value by dividing by 65535; all +channels are linear. Color channels use the RGB encoding (RGB end-points) of +the sRGB specification. This encoding is identified by the +PNG_FORMAT_FLAG_LINEAR flag below. + +When an alpha channel is present it is expected to denote pixel coverage +of the color or luminance channels and is returned as an associated alpha +channel: the color/gray channels are scaled (pre-multiplied) by the alpha +value. + +PNG_FORMAT_* + +The #defines to be used in png_image::format. Each #define identifies a +particular layout of channel data and, if present, alpha values. There are +separate defines for each of the two channel encodings. + +A format is built up using single bit flag values. Not all combinations are +valid: use the bit flag values below for testing a format returned by the +read APIs, but set formats from the derived values. + +NOTE: libpng can be built with particular features disabled, if you see +compiler errors because the definition of one of the following flags has been +compiled out it is because libpng does not have the required support. It is +possible, however, for the libpng configuration to enable the format on just +read or just write; in that case you may see an error at run time. You can +guard against this by checking for the definition of: + + PNG_SIMPLIFIED_{READ,WRITE}_{BGR,AFIRST}_SUPPORTED + + PNG_FORMAT_FLAG_ALPHA 0x01 format with an alpha channel + PNG_FORMAT_FLAG_COLOR 0x02 color format: otherwise grayscale + PNG_FORMAT_FLAG_LINEAR 0x04 png_uint_16 channels else png_byte + PNG_FORMAT_FLAG_BGR 0x08 BGR colors, else order is RGB + PNG_FORMAT_FLAG_AFIRST 0x10 alpha channel comes first + +Supported formats are as follows. Future versions of libpng may support more +formats; for compatibility with older versions simply check if the format +macro is defined using #ifdef. These defines describe the in-memory layout +of the components of the pixels of the image. + +First the single byte formats: + + PNG_FORMAT_GRAY 0 + PNG_FORMAT_GA PNG_FORMAT_FLAG_ALPHA + PNG_FORMAT_AG (PNG_FORMAT_GA|PNG_FORMAT_FLAG_AFIRST) + PNG_FORMAT_RGB PNG_FORMAT_FLAG_COLOR + PNG_FORMAT_BGR (PNG_FORMAT_FLAG_COLOR|PNG_FORMAT_FLAG_BGR) + PNG_FORMAT_RGBA (PNG_FORMAT_RGB|PNG_FORMAT_FLAG_ALPHA) + PNG_FORMAT_ARGB (PNG_FORMAT_RGBA|PNG_FORMAT_FLAG_AFIRST) + PNG_FORMAT_BGRA (PNG_FORMAT_BGR|PNG_FORMAT_FLAG_ALPHA) + PNG_FORMAT_ABGR (PNG_FORMAT_BGRA|PNG_FORMAT_FLAG_AFIRST) + +Then the linear (png_uint_16) formats. When naming these "Y" is used to +indicate a luminance (gray) channel. The component order within the pixel +is always the same - there is no provision for swapping the order of the +components in the linear format. + + PNG_FORMAT_LINEAR_Y PNG_FORMAT_FLAG_LINEAR + PNG_FORMAT_LINEAR_Y_ALPHA + (PNG_FORMAT_FLAG_LINEAR|PNG_FORMAT_FLAG_ALPHA) + PNG_FORMAT_LINEAR_RGB + (PNG_FORMAT_FLAG_LINEAR|PNG_FORMAT_FLAG_COLOR) + PNG_FORMAT_LINEAR_RGB_ALPHA + (PNG_FORMAT_FLAG_LINEAR|PNG_FORMAT_FLAG_COLOR| + PNG_FORMAT_FLAG_ALPHA) + +PNG_IMAGE macros + +These are convenience macros to derive information from a png_image structure: + + PNG_IMAGE_CHANNELS(fmt) + Returns the total number of channels in a given format: 1..4 + + PNG_IMAGE_COMPONENT_SIZE(fmt) + Returns the size in bytes of a single component of a pixel + in the image. + + PNG_IMAGE_PIXEL_SIZE(fmt) + Returns the size in bytes of a single pixel in the image. + + PNG_IMAGE_ROW_STRIDE(image) + Returns the total number of components in a single row + of the image; this is the minimum 'row stride', the minimum + count of components between each row. + + PNG_IMAGE_BUFFER_SIZE(image, row_stride) + Returns the size, in bytes, of an image buffer given + a png_image and a row stride - the number of components to + leave space for in each row. + + PNG_IMAGE_SIZE(image) + Returns the size, in bytes, of the image in memory given + just a png_image; the row stride is the minimum stride + required for the image. + +PNG_IMAGE_FLAG_ + +Flags containing additional information about the image are held + in the 'flags' field of png_image. + + PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB + This indicates the the RGB values of the in-memory + bitmap do not correspond to the red, green and blue + end-points defined by sRGB. + +READ APIs + + The png_image passed to the read APIs must have been initialized by setting + the png_controlp field 'opaque' to NULL (or, better, memset the whole thing.) + + int png_image_begin_read_from_file( png_imagep image, + const char *file_name) + + The named file is opened for read and the image header + is filled in from the PNG header in the file. + + + int png_image_begin_read_from_stdio (png_imagep image, + FILE* file) + + The PNG header is read from the stdio FILE object. + + int png_image_begin_read_from_memory(png_imagep image, + png_const_voidp memory, png_size_t size) + + The PNG header is read from the given memory buffer. + + int png_image_finish_read(png_imagep image, + png_colorp background, void *buffer, png_int_32 row_stride)); + + Finish reading the image into the supplied buffer and + clean up the png_image structure. + + row_stride is the step, in png_byte or png_uint_16 units + as appropriate, between adjacent rows. A positive stride + indicates that the top-most row is first in the buffer - + the normal top-down arrangement. A negative stride + indicates that the bottom-most row is first in the buffer. + + background need only be supplied if an alpha channel must + be removed from a png_byte format and the removal is to be + done by compositing on a solid color; otherwise it may be + NULL and any composition will be done directly onto the + buffer. The value is an sRGB color to use for the + background, for grayscale output the green channel is used. + + For linear output removing the alpha channel is always done + by compositing on black. + + void png_image_free(png_imagep image) + + Free any data allocated by libpng in image->opaque, + setting the pointer to NULL. May be called at any time + after the structure is initialized. + + +WRITE APIS + +For write you must initialize a png_image structure to describe the image to +be written: + + opaque: must be initialized to NULL + width: image width in pixels + height: image height in rows + format: the format of the data you wish to write + flags: set to 0 unless one of the defined flags applies; set + PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB for color format images + where the RGB values do not correspond to the colors in sRGB. + + int png_image_write_to_file, (png_imagep image, + const char *file, int convert_to_8bit, const void *buffer, + png_int_32 row_stride)); + + Write the image to the named file. + + int png_image_write_to_stdio(png_imagep image, FILE *file, + int convert_to_8_bit, const void *buffer, png_int_32 row_stride) + + Write the image to the given (FILE*). + +With all write APIs if image is in one of the linear formats with +(png_uint_16) data then setting convert_to_8_bit will cause the output to be +a (png_byte) PNG gamma encoded according to the sRGB specification, otherwise +a 16-bit linear encoded PNG file is written. + +With all APIs row_stride is handled as in the read APIs - it is the spacing +from one row to the next in component sized units (float) and if negative +indicates a bottom-up row layout in the buffer. + +Note that the write API does not support interlacing, sub-8-bit pixels, +and indexed (paletted) images. + +.SH VI. Modifying/Customizing libpng There are two issues here. The first is changing how libpng does standard things like memory allocation, input/output, and error handling. @@ -4875,7 +4653,7 @@ When PNG_DEBUG = 1, the macros are defined, but only png_debug statements having level = 0 will be printed. There aren't any such statements in this version of libpng, but if you insert some they will be printed. -.SH VI. MNG support +.SH VII. MNG support The MNG specification (available at http://www.libpng.org/pub/mng) allows certain extensions to PNG for PNG images that are embedded in MNG datastreams. @@ -4902,7 +4680,7 @@ or any other MNG chunks; your application must provide its own support for them. You may wish to consider using libmng (available at http://www.libmng.com) instead. -.SH VII. Changes to Libpng from version 0.88 +.SH VIII. Changes to Libpng from version 0.88 It should be noted that versions of libpng later than 0.96 are not distributed by the original libpng author, Guy Schalnat, nor by @@ -4954,7 +4732,7 @@ application: png_uint_32 application_vn = PNG_LIBPNG_VER; -.SH VIII. Changes to Libpng from version 1.0.x to 1.2.x +.SH IX. Changes to Libpng from version 1.0.x to 1.2.x Support for user memory management was enabled by default. To accomplish this, the functions png_create_read_struct_2(), @@ -5051,7 +4829,7 @@ which also expands tRNS to alpha was replaced with png_set_expand_gray_1_2_4_to_8() which does not. It has been deprecated since libpng-1.0.18 and 1.2.9. -.SH IX. Changes to Libpng from version 1.0.x/1.2.x to 1.4.x +.SH X. Changes to Libpng from version 1.0.x/1.2.x to 1.4.x Private libpng prototypes and macro definitions were moved from png.h and pngconf.h into a new pngpriv.h header file. @@ -5159,7 +4937,7 @@ was renamed to PNG_READ_QUANTIZE_SUPPORTED. We removed the trailing '.' from the warning and error messages. -.SH X. Changes to Libpng from version 1.4.x to 1.5.x +.SH XI. Changes to Libpng from version 1.4.x to 1.5.x From libpng-1.4.0 until 1.4.4, the png_get_uint_16 macro (but not the function) incorrectly returned a value of type png_uint_32. @@ -5449,7 +5227,10 @@ pngusr.h a system builder may also define equivalent options in pngusr.dfa DFA_XTRA to the file name. The makefiles in contrib/pngminim illustrate how to do this, and a case where pngusr.h is still required. -.SH XI. Changes to Libpng from version 1.5.x to 1.6.x +.SH XII. Changes to Libpng from version 1.5.x to 1.6.x + +A "simplified API" has been added (see documentation in png.h and a simple +example in contrib/examples/pngtopng.c) We no longer include string.h in png.h. The include statement has been moved to pngpriv.h, where it is not accessible by applications. Applications that @@ -5470,10 +5251,7 @@ The following has been removed: function returns a 32-bit integer instead of a string. -A "simplified API" has been added (see documentation in png.h and a simple -example in contrib/examples/pngtopng.c) - -.SH XII. Detecting libpng +.SH XIII. Detecting libpng The png_get_io_ptr() function has been present since libpng-0.88, has never changed, and is unaffected by conditional compilation macros. It is the @@ -5482,7 +5260,7 @@ libpng version since 0.88. In an autoconf "configure.in" you could use AC_CHECK_LIB(png, png_get_io_ptr, ... -.SH XIII. Source code repository +.SH XV. Source code repository Since about February 2009, version 1.2.34, libpng has been under "git" source control. The git repository was built from old libpng-x.y.z.tar.gz files @@ -5506,7 +5284,7 @@ simple verbal discriptions of bug fixes, reported either to the SourceForge bug tracker, to the png-mng-implement at lists.sf.net mailing list, or directly to glennrp. -.SH XIV. Coding style +.SH XV. Coding style Our coding style is similar to the "Allman" style, with curly braces on separate lines: @@ -5618,9 +5396,9 @@ Lines do not exceed 80 characters. Other rules can be inferred by inspecting the libpng source. -.SH XV. Y2K Compliance in libpng +.SH XVI. Y2K Compliance in libpng -December 30, 2011 +January 11, 2012 Since the PNG Development group is an ad-hoc body, we can't make an official declaration. @@ -5888,7 +5666,7 @@ possible without all of you. Thanks to Frank J. T. Wojcik for helping with the documentation. -Libpng version 1.6.0beta05 - December 30, 2011: +Libpng version 1.6.0beta05 - January 11, 2012: Initially created in 1995 by Guy Eric Schalnat, then of Group 42, Inc. Currently maintained by Glenn Randers-Pehrson (glennrp at users.sourceforge.net). @@ -5911,7 +5689,7 @@ this sentence. This code is released under the libpng license. -libpng versions 1.2.6, August 15, 2004, through 1.6.0beta05, December 30, 2011, are +libpng versions 1.2.6, August 15, 2004, through 1.6.0beta05, January 11, 2012, are Copyright (c) 2004,2006-2007 Glenn Randers-Pehrson, and are distributed according to the same disclaimer and license as libpng-1.2.5 with the following individual added to the list of Contributing Authors @@ -6010,7 +5788,7 @@ certification mark of the Open Source Initiative. Glenn Randers-Pehrson glennrp at users.sourceforge.net -December 30, 2011 +January 11, 2012 .\" end of man page