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[devel] Fixed pngvalid, simplified macros, added checking for 0 in sCAL.

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This commit is contained in:
John Bowler
2011-06-18 13:37:11 -05:00
committed by Glenn Randers-Pehrson
parent c4a8214b77
commit 8d261262d9
11 changed files with 219 additions and 140 deletions
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51
pngvalid.c
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@@ -5281,9 +5281,9 @@ image_transform_png_set_scale_16_add(image_transform *this,
IT(scale_16);
#undef PT
#define PT ITSTRUCT(scale_16)
#endif
#endif /* PNG_READ_SCALE_16_TO_8_SUPPORTED (1.5.4 on) */
#ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED /* the default before 1.5.4 */
#ifdef PNG_READ_16_TO_8_SUPPORTED /* the default before 1.5.4 */
/* png_set_strip_16 */
static void
image_transform_png_set_strip_16_set(PNG_CONST image_transform *this,
@@ -5305,18 +5305,28 @@ image_transform_png_set_strip_16_mod(PNG_CONST image_transform *this,
if (that->blue_sBIT > 8) that->blue_sBIT = 8;
if (that->alpha_sBIT > 8) that->alpha_sBIT = 8;
/* The strip 16 algorithm drops the low 8 bits rather than calculating
* 1/257, so we need to adjust the permitted errors appropriately:
* Notice that this is only relevant prior to the addition of the
* png_set_scale_16 API in 1.5.4 (but 1.5.4+ always defines the above!)
/* Prior to 1.5.4 png_set_strip_16 would use an 'accurate' method if this
* configuration option is set. From 1.5.4 the flag is never set and the
* 'scale' API (above) must be used.
*/
{
PNG_CONST double d = (255-128.5)/65535;
that->rede += d;
that->greene += d;
that->bluee += d;
that->alphae += d;
}
# ifdef PNG_READ_ACCURATE_SCALE_SUPPORTED
# if PNG_LIBPNG_VER >= 10504
# error PNG_READ_ACCURATE_SCALE should not be set
# endif
/* The strip 16 algorithm drops the low 8 bits rather than calculating
* 1/257, so we need to adjust the permitted errors appropriately:
* Notice that this is only relevant prior to the addition of the
* png_set_scale_16 API in 1.5.4 (but 1.5.4+ always defines the above!)
*/
{
PNG_CONST double d = (255-128.5)/65535;
that->rede += d;
that->greene += d;
that->bluee += d;
that->alphae += d;
}
# endif
}
this->next->mod(this->next, that, pp, display);
@@ -5337,7 +5347,7 @@ image_transform_png_set_strip_16_add(image_transform *this,
IT(strip_16);
#undef PT
#define PT ITSTRUCT(strip_16)
#endif /* PNG_READ_STRIP_16_TO_8_SUPPORTED, from libpng 1.5.4 */
#endif /* PNG_READ_16_TO_8_SUPPORTED */
#ifdef PNG_READ_STRIP_ALPHA_SUPPORTED
/* png_set_strip_alpha */
@@ -6102,7 +6112,12 @@ gamma_info_imp(gamma_display *dp, png_structp pp, png_infop pi)
# ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED
png_set_scale_16(pp);
# else
png_error(pp, "scale16 (16 to 8 bit conversion) not supported");
/* The following works both in 1.5.4 and earlier versions: */
# ifdef PNG_READ_16_TO_8_SUPPORTED
png_set_strip_16(pp);
# else
png_error(pp, "scale16 (16 to 8 bit conversion) not supported");
# endif
# endif
if (dp->expand16)
@@ -6713,8 +6728,12 @@ gamma_component_validate(PNG_CONST char *name, PNG_CONST validate_info *vi,
* option has been used and 'inaccurate' scaling is used then the
* bit reduction is obtained by simply using the top 8 bits of the
* value.
*
* This is only done for older libpng versions when the 'inaccurate'
* (chop) method of scaling was used.
*/
# if 0 /*WAS: #ifndef PNG_READ_16_TO_8_ACCURATE_SCALE_SUPPORTED */
# if !PNG_READ_16_TO_8_ACCURATE_SCALE_SUPPORTED && \
PNG_LIBPNG_VER < 10504
/* This may be required for other components in the future, but
* at present the presence of gamma correction effectively
* prevents the errors in the component scaling (I don't quite