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[libpng16] Edited new commentary in png.c

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This commit is contained in:
Glenn Randers-Pehrson 2012-03-29 08:28:19 -05:00
parent f229d4df3a
commit 747b554a86
1 changed files with 12 additions and 12 deletions
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24
png.c
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@ -1896,14 +1896,14 @@ png_icc_check_header(png_const_structrp png_ptr, png_colorspacerp colorspace,
"intent outside defined range");
/* At this point the tag table can't be checked because it hasn't necessarily
* been loaded, however various header fields can be checked. These checks
* been loaded; however, various header fields can be checked. These checks
* are for values permitted by the PNG spec in an ICC profile; the PNG spec
* restricts the profiles than can be passed in an iCCP chunk (they must be
* restricts the profiles that can be passed in an iCCP chunk (they must be
* appropriate to processing PNG data!)
*/
/* Data checks (could be skipped). These checks must be independent of the
* version number, however the version number doesn't accomodate changes in
* version number; however, the version number doesn't accomodate changes in
* the header fields (just the known tags and the interpretation of the
* data.)
*/
@ -1921,10 +1921,10 @@ png_icc_check_header(png_const_structrp png_ptr, png_colorspacerp colorspace,
* and 4)."
*
* This code does not check the color type because png_set_iCCP may be called
* before png_set_IHDR on write and because, anyway, the spec is
* before png_set_IHDR on write and because, anyway, the PNG spec is
* fundamentally flawed: RGB profiles can be used quite meaningfully for
* grayscale images and both RGB and palette images may only have gray colors
* in them, so gray profiles may be appropriate.
* grayscale images and both RGB and palette images might only have gray
* colors in them, so gray profiles may be appropriate.
*/
temp = png_get_uint_32(profile+16); /* data colour space field */
if (temp != 0x52474220 /* 'RGB ' */ && temp != 0x47524159 /* 'GRAY' */)
@ -2011,7 +2011,7 @@ static const struct
PNG_MD5(0x34562abf, 0x994ccd06, 0x6d2c5721, 0xd0d68c5d), 0,
"2007/07/25 00:05:37", 60960, "sRGB_v4_ICC_preference.icc")
/* The following profiles have no known MD5 checksum, if there is a match
/* The following profiles have no known MD5 checksum. If there is a match
* on the (empty) MD5 the other fields are used to attempt a match and
* a warning is produced. The first two of these profiles have a 'cprt' tag
* which suggests that they were also made by Hewlett Packard.
@ -2033,10 +2033,10 @@ static int
png_compare_ICC_profile_with_sRGB(png_const_structrp png_ptr,
png_const_bytep profile, uLong adler)
{
/* The quick check is to verify just the MD5 signature and trust to the
/* The quick check is to verify just the MD5 signature and trust the
* rest of the data. Because the profile has already been verified for
* correctness this is safe. png_colorspace_set_sRGB will check the 'intent'
* field too, so if the profile has been editted with an intent not defined
* field too, so if the profile has been edited with an intent not defined
* by sRGB (but maybe defined by a later ICC specification) the read of
* the profile will fail at that point.
*/
@ -2050,8 +2050,8 @@ png_compare_ICC_profile_with_sRGB(png_const_structrp png_ptr,
for (i=0; i < (sizeof png_sRGB_checks) / (sizeof png_sRGB_checks[0]); ++i)
{
if (png_get_uint_32(profile+84) == png_sRGB_checks[i].md5[0] &&
png_get_uint_32(profile+88) == png_sRGB_checks[i].md5[1] &&
png_get_uint_32(profile+92) == png_sRGB_checks[i].md5[2] &&
png_get_uint_32(profile+88) == png_sRGB_checks[i].md5[1] &&
png_get_uint_32(profile+92) == png_sRGB_checks[i].md5[2] &&
png_get_uint_32(profile+96) == png_sRGB_checks[i].md5[3])
{
/* This may be one of the old HP profiles without an MD5, in that
@ -2142,7 +2142,7 @@ png_icc_set_gAMA_and_cHRM(png_const_structrp png_ptr,
uLong adler, int preferred)
{
# ifdef PNG_sRGB_SUPPORTED
/* 1) Is this profile one of the known ICC sRGB profiles? If it is just
/* 1) Is this profile one of the known ICC sRGB profiles? If it is, just
* set the sRGB information.
*/
if (png_compare_ICC_profile_with_sRGB(png_ptr, profile, adler))