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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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20
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"); "intent outside defined range");
/* At this point the tag table can't be checked because it hasn't necessarily /* 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 * 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!) * appropriate to processing PNG data!)
*/ */
/* Data checks (could be skipped). These checks must be independent of the /* 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 * the header fields (just the known tags and the interpretation of the
* data.) * data.)
*/ */
@ -1921,10 +1921,10 @@ png_icc_check_header(png_const_structrp png_ptr, png_colorspacerp colorspace,
* and 4)." * and 4)."
* *
* This code does not check the color type because png_set_iCCP may be called * 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 * fundamentally flawed: RGB profiles can be used quite meaningfully for
* grayscale images and both RGB and palette images may only have gray colors * grayscale images and both RGB and palette images might only have gray
* in them, so gray profiles may be appropriate. * colors in them, so gray profiles may be appropriate.
*/ */
temp = png_get_uint_32(profile+16); /* data colour space field */ temp = png_get_uint_32(profile+16); /* data colour space field */
if (temp != 0x52474220 /* 'RGB ' */ && temp != 0x47524159 /* 'GRAY' */) if (temp != 0x52474220 /* 'RGB ' */ && temp != 0x47524159 /* 'GRAY' */)
@ -2011,7 +2011,7 @@ static const struct
PNG_MD5(0x34562abf, 0x994ccd06, 0x6d2c5721, 0xd0d68c5d), 0, PNG_MD5(0x34562abf, 0x994ccd06, 0x6d2c5721, 0xd0d68c5d), 0,
"2007/07/25 00:05:37", 60960, "sRGB_v4_ICC_preference.icc") "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 * 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 * a warning is produced. The first two of these profiles have a 'cprt' tag
* which suggests that they were also made by Hewlett Packard. * 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_compare_ICC_profile_with_sRGB(png_const_structrp png_ptr,
png_const_bytep profile, uLong adler) 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 * rest of the data. Because the profile has already been verified for
* correctness this is safe. png_colorspace_set_sRGB will check the 'intent' * 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 * by sRGB (but maybe defined by a later ICC specification) the read of
* the profile will fail at that point. * the profile will fail at that point.
*/ */
@ -2142,7 +2142,7 @@ png_icc_set_gAMA_and_cHRM(png_const_structrp png_ptr,
uLong adler, int preferred) uLong adler, int preferred)
{ {
# ifdef PNG_sRGB_SUPPORTED # 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. * set the sRGB information.
*/ */
if (png_compare_ICC_profile_with_sRGB(png_ptr, profile, adler)) if (png_compare_ICC_profile_with_sRGB(png_ptr, profile, adler))