+++ /dev/null
-commit a21a5b22c10b900d44d40fe30a203302b2a67f8b
-Author: John Bowler <jbowler@acm.org>
-Date: Mon Mar 30 21:38:31 2015 -0500
-
- [libpng16] Fixed rgb_to_gray checks and added tRNS checks to pngvalid.c
-
-#diff --git a/ANNOUNCE b/ANNOUNCE
-#index 73fadac..7e6c842 100644
-#--- a/ANNOUNCE
-#+++ b/ANNOUNCE
-#@@ -1,4 +1,4 @@
-#-Libpng 1.6.18beta01 - March 27, 2015
-#+Libpng 1.6.18beta01 - March 31, 2015
-#
-# 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.
-#@@ -25,10 +25,11 @@ Other information:
-#
-# Changes since the last public release (1.6.17):
-#
-#-Version 1.6.18beta01 [March 27, 2015]
-#+Version 1.6.18beta01 [March 31, 2015]
-# Removed PNG_SET_CHUNK_[CACHE|MALLOC]_LIMIT_SUPPORTED macros. They
-# have been combined with PNG_SET_USER_LIMITS_SUPPORTED (resolves
-# bug report by Andrew Church).
-#+ Fixed rgb_to_gray checks and added tRNS checks to pngvalid.c
-#
-# Send comments/corrections/commendations to png-mng-implement at lists.sf.net
-# (subscription required; visit
-#diff --git a/CHANGES b/CHANGES
-#index fe07211..35b5979 100644
-#--- a/CHANGES
-#+++ b/CHANGES
-#@@ -5205,10 +5205,11 @@ Version 1.6.17rc06 [March 23, 2015]
-# Version 1.6.17 [March 26, 2015]
-# No changes.
-#
-#-Version 1.6.18beta01 [March 27, 2015]
-#+Version 1.6.18beta01 [March 31, 2015]
-# Removed PNG_SET_CHUNK_[CACHE|MALLOC]_LIMIT_SUPPORTED macros. They
-# have been combined with PNG_SET_USER_LIMITS_SUPPORTED (resolves
-# bug report by Andrew Church).
-#+ Fixed rgb_to_gray checks and added tRNS checks to pngvalid.c
-#
-# Send comments/corrections/commendations to png-mng-implement at lists.sf.net
-# (subscription required; visit
-diff --git a/autogen.sh b/autogen.sh
-index 9af34bd..702a0c1 100755
---- a/autogen.sh
-+++ b/autogen.sh
-@@ -73,8 +73,9 @@ done
- # present bad things are happening.
- #
- # The autotools generated files:
--libpng_autotools_files="Makefile.in aclocal.m4 config.guess config.h.in\
-- config.sub configure depcomp install-sh ltmain.sh missing test-driver"
-+libpng_autotools_files="Makefile.in aclocal.m4 config.guess config.h.in
-+ config.h.in~ config.sub configure depcomp install-sh ltmain.sh missing\
-+ test-driver"
- #
- # Files generated by versions of configue >2.68 or automake >1.13 (i.e. later
- # versions than those required by configure.ac):
-diff --git a/contrib/libtests/pngvalid.c b/contrib/libtests/pngvalid.c
-index 8852f87..60f23dc 100644
---- a/contrib/libtests/pngvalid.c
-+++ b/contrib/libtests/pngvalid.c
-@@ -258,7 +258,7 @@ make_four_random_bytes(png_uint_32* seed, png_bytep bytes)
- make_random_bytes(seed, bytes, 4);
- }
-
--#ifdef PNG_READ_SUPPORTED
-+#if defined PNG_READ_SUPPORTED || defined PNG_WRITE_tRNS_SUPPORTED
- static void
- randomize(void *pv, size_t size)
- {
-@@ -267,7 +267,9 @@ randomize(void *pv, size_t size)
- }
-
- #define RANDOMIZE(this) randomize(&(this), sizeof (this))
-+#endif /* READ || WRITE_tRNS */
-
-+#ifdef PNG_READ_SUPPORTED
- static unsigned int
- random_mod(unsigned int max)
- {
-@@ -295,7 +297,8 @@ random_choice(void)
- /* A numeric ID based on PNG file characteristics. The 'do_interlace' field
- * simply records whether pngvalid did the interlace itself or whether it
- * was done by libpng. Width and height must be less than 256. 'palette' is an
-- * index of the palette to use for formats with a palette (0 otherwise.)
-+ * index of the palette to use for formats with a palette otherwise a boolean
-+ * indicating if a tRNS chunk was generated.
- */
- #define FILEID(col, depth, palette, interlace, width, height, do_interlace) \
- ((png_uint_32)((col) + ((depth)<<3) + ((palette)<<8) + ((interlace)<<13) + \
-@@ -316,12 +319,16 @@ standard_name(char *buffer, size_t bufsize, size_t pos, png_byte colour_type,
- png_uint_32 w, png_uint_32 h, int do_interlace)
- {
- pos = safecat(buffer, bufsize, pos, colour_types[colour_type]);
-- if (npalette > 0)
-+ if (colour_type == 3) /* must have a palette */
- {
- pos = safecat(buffer, bufsize, pos, "[");
- pos = safecatn(buffer, bufsize, pos, npalette);
- pos = safecat(buffer, bufsize, pos, "]");
- }
-+
-+ else if (npalette != 0)
-+ pos = safecat(buffer, bufsize, pos, "+tRNS");
-+
- pos = safecat(buffer, bufsize, pos, " ");
- pos = safecatn(buffer, bufsize, pos, bit_depth);
- pos = safecat(buffer, bufsize, pos, " bit");
-@@ -378,25 +385,32 @@ standard_name_from_id(char *buffer, size_t bufsize, size_t pos, png_uint_32 id)
-
- static int
- next_format(png_bytep colour_type, png_bytep bit_depth,
-- unsigned int* palette_number, int no_low_depth_gray)
-+ unsigned int* palette_number, int low_depth_gray, int tRNS)
- {
- if (*bit_depth == 0)
- {
- *colour_type = 0;
-- if (no_low_depth_gray)
-- *bit_depth = 8;
-- else
-+ if (low_depth_gray)
- *bit_depth = 1;
-+ else
-+ *bit_depth = 8;
- *palette_number = 0;
- return 1;
- }
-
-- if (*colour_type == 3)
-+ if (*colour_type < 4/*no alpha channel*/)
- {
-- /* Add multiple palettes for colour type 3. */
-- if (++*palette_number < PALETTE_COUNT(*bit_depth))
-+ /* Add multiple palettes for colour type 3, one image with tRNS
-+ * and one without for other non-alpha formats:
-+ */
-+ unsigned int pn = ++*palette_number;
-+ png_byte ct = *colour_type;
-+
-+ if (((ct == 0/*GRAY*/ || ct/*RGB*/ == 2) && tRNS && pn < 2) ||
-+ (ct == 3/*PALETTE*/ && pn < PALETTE_COUNT(*bit_depth)))
- return 1;
-
-+ /* No: next bit depth */
- *palette_number = 0;
- }
-
-@@ -1959,6 +1973,7 @@ typedef struct png_modifier
-
- /* Run tests on reading with a combination of transforms, */
- unsigned int test_transform :1;
-+ unsigned int test_tRNS :1; /* Includes tRNS images */
-
- /* When to use the use_input_precision option, this controls the gamma
- * validation code checks. If set any value that is within the transformed
-@@ -1990,6 +2005,16 @@ typedef struct png_modifier
- unsigned int test_gamma_expand16 :1;
- unsigned int test_exhaustive :1;
-
-+ /* Whether or not to run the low-bit-depth grayscale tests. This fail on
-+ * gamma images in some cases because of gross inaccuracies in the grayscale
-+ * gamma handling for low bit depth.
-+ */
-+ unsigned int test_lbg :1;
-+ unsigned int test_lbg_gamma_threshold :1;
-+ unsigned int test_lbg_gamma_transform :1;
-+ unsigned int test_lbg_gamma_sbit :1;
-+ unsigned int test_lbg_gamma_composition :1;
-+
- unsigned int log :1; /* Log max error */
-
- /* Buffer information, the buffer size limits the size of the chunks that can
-@@ -2042,6 +2067,11 @@ modifier_init(png_modifier *pm)
- pm->test_standard = 0;
- pm->test_size = 0;
- pm->test_transform = 0;
-+# ifdef PNG_WRITE_tRNS_SUPPORTED
-+ pm->test_tRNS = 1;
-+# else
-+ pm->test_tRNS = 0;
-+# endif
- pm->use_input_precision = 0;
- pm->use_input_precision_sbit = 0;
- pm->use_input_precision_16to8 = 0;
-@@ -2054,6 +2084,11 @@ modifier_init(png_modifier *pm)
- pm->test_gamma_background = 0;
- pm->test_gamma_alpha_mode = 0;
- pm->test_gamma_expand16 = 0;
-+ pm->test_lbg = 1;
-+ pm->test_lbg_gamma_threshold = 1;
-+ pm->test_lbg_gamma_transform = 1;
-+ pm->test_lbg_gamma_sbit = 1;
-+ pm->test_lbg_gamma_composition = 1;
- pm->test_exhaustive = 0;
- pm->log = 0;
-
-@@ -3192,6 +3227,45 @@ init_standard_palette(png_store *ps, png_structp pp, png_infop pi, int npalette,
- }
- }
-
-+#ifdef PNG_WRITE_tRNS_SUPPORTED
-+static void
-+set_random_tRNS(png_structp pp, png_infop pi, PNG_CONST png_byte colour_type,
-+ PNG_CONST int bit_depth)
-+{
-+ /* To make this useful the tRNS color needs to match at least one pixel.
-+ * Random values are fine for gray, including the 16-bit case where we know
-+ * that the test image contains all the gray values. For RGB we need more
-+ * method as only 65536 different RGB values are generated.
-+ */
-+ png_color_16 tRNS;
-+ const png_uint_16 mask = (png_uint_16)((1U << bit_depth)-1);
-+
-+ RANDOMIZE(tRNS);
-+
-+ if (colour_type & 2/*RGB*/)
-+ {
-+ if (bit_depth == 8)
-+ {
-+ tRNS.blue = tRNS.red ^ tRNS.green;
-+ tRNS.red &= mask;
-+ tRNS.green &= mask;
-+ tRNS.blue &= mask;
-+ }
-+
-+ else /* bit_depth == 16 */
-+ {
-+ tRNS.green = (png_uint_16)(tRNS.red * 257);
-+ tRNS.blue = (png_uint_16)(tRNS.green * 17);
-+ }
-+ }
-+
-+ else
-+ tRNS.gray &= mask;
-+
-+ png_set_tRNS(pp, pi, NULL, 0, &tRNS);
-+}
-+#endif
-+
- /* The number of passes is related to the interlace type. There was no libpng
- * API to determine this prior to 1.5, so we need an inquiry function:
- */
-@@ -3525,6 +3599,11 @@ make_transform_image(png_store* PNG_CONST ps, png_byte PNG_CONST colour_type,
- if (colour_type == 3) /* palette */
- init_standard_palette(ps, pp, pi, 1U << bit_depth, 1/*do tRNS*/);
-
-+# ifdef PNG_WRITE_tRNS_SUPPORTED
-+ else if (palette_number)
-+ set_random_tRNS(pp, pi, colour_type, bit_depth);
-+# endif
-+
- png_write_info(pp, pi);
-
- if (png_get_rowbytes(pp, pi) !=
-@@ -3598,19 +3677,20 @@ make_transform_image(png_store* PNG_CONST ps, png_byte PNG_CONST colour_type,
- }
-
- static void
--make_transform_images(png_store *ps)
-+make_transform_images(png_modifier *pm)
- {
- png_byte colour_type = 0;
- png_byte bit_depth = 0;
- unsigned int palette_number = 0;
-
- /* This is in case of errors. */
-- safecat(ps->test, sizeof ps->test, 0, "make standard images");
-+ safecat(pm->this.test, sizeof pm->this.test, 0, "make standard images");
-
- /* Use next_format to enumerate all the combinations we test, including
-- * generating multiple low bit depth palette images.
-+ * generating multiple low bit depth palette images. Non-A images (palette
-+ * and direct) are created with and without tRNS chunks.
- */
-- while (next_format(&colour_type, &bit_depth, &palette_number, 0))
-+ while (next_format(&colour_type, &bit_depth, &palette_number, 1, 1))
- {
- int interlace_type;
-
-@@ -3621,7 +3701,7 @@ make_transform_images(png_store *ps)
-
- standard_name(name, sizeof name, 0, colour_type, bit_depth,
- palette_number, interlace_type, 0, 0, 0);
-- make_transform_image(ps, colour_type, bit_depth, palette_number,
-+ make_transform_image(&pm->this, colour_type, bit_depth, palette_number,
- interlace_type, name);
- }
- }
-@@ -4287,6 +4367,7 @@ typedef struct standard_display
- size_t cbRow; /* Bytes in a row of the output image */
- int do_interlace; /* Do interlacing internally */
- int is_transparent; /* Transparency information was present. */
-+ int has_tRNS; /* color type GRAY or RGB with a tRNS chunk. */
- int speed; /* Doing a speed test */
- int use_update_info;/* Call update_info, not start_image */
- struct
-@@ -4619,14 +4700,14 @@ standard_info_part1(standard_display *dp, png_structp pp, png_infop pi)
- case 0:
- dp->transparent.red = dp->transparent.green = dp->transparent.blue =
- trans_color->gray;
-- dp->is_transparent = 1;
-+ dp->has_tRNS = 1;
- break;
-
- case 2:
- dp->transparent.red = trans_color->red;
- dp->transparent.green = trans_color->green;
- dp->transparent.blue = trans_color->blue;
-- dp->is_transparent = 1;
-+ dp->has_tRNS = 1;
- break;
-
- case 3:
-@@ -5518,7 +5599,7 @@ image_pixel_add_alpha(image_pixel *this, PNG_CONST standard_display *display)
- if (this->colour_type == PNG_COLOR_TYPE_GRAY)
- {
- if (this->bit_depth < 8)
-- this->bit_depth = 8;
-+ this->bit_depth = this->sample_depth = 8;
-
- if (this->have_tRNS)
- {
-@@ -5553,9 +5634,11 @@ image_pixel_add_alpha(image_pixel *this, PNG_CONST standard_display *display)
- this->alphaf = 0;
- else
- this->alphaf = 1;
--
-- this->colour_type = PNG_COLOR_TYPE_RGB_ALPHA;
- }
-+ else
-+ this->alphaf = 1;
-+
-+ this->colour_type = PNG_COLOR_TYPE_RGB_ALPHA;
- }
-
- /* The error in the alpha is zero and the sBIT value comes from the
-@@ -5848,8 +5931,9 @@ transform_info_imp(transform_display *dp, png_structp pp, png_infop pi)
- /* If png_set_filler is in action then fake the output color type to include
- * an alpha channel where appropriate.
- */
-- if (dp->output_bit_depth >= 8 && (dp->output_colour_type == PNG_COLOR_TYPE_RGB ||
-- dp->output_colour_type == PNG_COLOR_TYPE_GRAY) && dp->this.filler)
-+ if (dp->output_bit_depth >= 8 &&
-+ (dp->output_colour_type == PNG_COLOR_TYPE_RGB ||
-+ dp->output_colour_type == PNG_COLOR_TYPE_GRAY) && dp->this.filler)
- dp->output_colour_type |= 4;
-
- /* Validate the combination of colour type and bit depth that we are getting
-@@ -6372,6 +6456,13 @@ image_transform_png_set_tRNS_to_alpha_set(PNG_CONST image_transform *this,
- transform_display *that, png_structp pp, png_infop pi)
- {
- png_set_tRNS_to_alpha(pp);
-+
-+ /* If there was a tRNS chunk that would get expanded and add an alpha
-+ * channel is_transparent must be updated:
-+ */
-+ if (that->this.has_tRNS)
-+ that->this.is_transparent = 1;
-+
- this->next->set(this->next, that, pp, pi);
- }
-
-@@ -6430,6 +6521,7 @@ image_transform_png_set_gray_to_rgb_set(PNG_CONST image_transform *this,
- transform_display *that, png_structp pp, png_infop pi)
- {
- png_set_gray_to_rgb(pp);
-+ /* NOTE: this doesn't result in tRNS expansion. */
- this->next->set(this->next, that, pp, pi);
- }
-
-@@ -6489,6 +6581,10 @@ image_transform_png_set_expand_set(PNG_CONST image_transform *this,
- transform_display *that, png_structp pp, png_infop pi)
- {
- png_set_expand(pp);
-+
-+ if (that->this.has_tRNS)
-+ that->this.is_transparent = 1;
-+
- this->next->set(this->next, that, pp, pi);
- }
-
-@@ -6539,6 +6635,7 @@ image_transform_png_set_expand_gray_1_2_4_to_8_set(
- png_infop pi)
- {
- png_set_expand_gray_1_2_4_to_8(pp);
-+ /* NOTE: don't expect this to expand tRNS */
- this->next->set(this->next, that, pp, pi);
- }
-
-@@ -6570,6 +6667,11 @@ image_transform_png_set_expand_16_set(PNG_CONST image_transform *this,
- transform_display *that, png_structp pp, png_infop pi)
- {
- png_set_expand_16(pp);
-+
-+ /* NOTE: at present libpng does SET_EXPAND as well, so tRNS is expanded. */
-+ if (that->this.has_tRNS)
-+ that->this.is_transparent = 1;
-+
- this->next->set(this->next, that, pp, pi);
- }
-
-@@ -6940,14 +7042,14 @@ image_transform_png_set_rgb_to_gray_ini(PNG_CONST image_transform *this,
- * When DIGITIZE is set because a pre-1.7 version of libpng is being
- * tested allow a bigger slack.
- *
-- * NOTE: this magic number was determined by experiment to be 1.25.
-- * There's no great merit to the value below, however it only affects
-- * the limit used for checking for internal calculation errors, not
-- * the actual limit imposed by pngvalid on the output errors.
-+ * NOTE: this magic number was determined by experiment to be about
-+ * 1.263. There's no great merit to the value below, however it only
-+ * affects the limit used for checking for internal calculation errors,
-+ * not the actual limit imposed by pngvalid on the output errors.
- */
- that->pm->limit += pow(
- # if DIGITIZE
-- 1.25
-+ 1.3
- # else
- 1.0
- # endif
-@@ -7111,7 +7213,8 @@ image_transform_png_set_rgb_to_gray_mod(PNG_CONST image_transform *this,
- const unsigned int sample_depth = that->sample_depth;
- const unsigned int calc_depth = (pm->assume_16_bit_calculations ? 16 :
- sample_depth);
-- const unsigned int gamma_depth = (sample_depth == 16 ? 16 :
-+ const unsigned int gamma_depth = (sample_depth == 16 ?
-+ PNG_MAX_GAMMA_8 :
- (pm->assume_16_bit_calculations ? PNG_MAX_GAMMA_8 : sample_depth));
- int isgray;
- double r, g, b;
-@@ -7125,56 +7228,73 @@ image_transform_png_set_rgb_to_gray_mod(PNG_CONST image_transform *this,
- * will be identical after this operation if there is only one
- * transform, feel free to delete the png_error checks on this below in
- * the future (this is just me trying to ensure it works!)
-+ *
-+ * Interval arithmetic is exact, but to implement it it must be
-+ * possible to control the floating point implementation rounding mode.
-+ * This cannot be done in ANSI-C, so instead I reduce the 'lo' values
-+ * by DBL_EPSILON and increase the 'hi' values by the same.
- */
-+# define DD(v,d,r) (digitize(v*(1-DBL_EPSILON), d, r) * (1-DBL_EPSILON))
-+# define DU(v,d,r) (digitize(v*(1+DBL_EPSILON), d, r) * (1+DBL_EPSILON))
-+
- r = rlo = rhi = that->redf;
- rlo -= that->rede;
-- rlo = digitize(rlo, calc_depth, 1/*round*/);
-+ rlo = DD(rlo, calc_depth, 1/*round*/);
- rhi += that->rede;
-- rhi = digitize(rhi, calc_depth, 1/*round*/);
-+ rhi = DU(rhi, calc_depth, 1/*round*/);
-
- g = glo = ghi = that->greenf;
- glo -= that->greene;
-- glo = digitize(glo, calc_depth, 1/*round*/);
-+ glo = DD(glo, calc_depth, 1/*round*/);
- ghi += that->greene;
-- ghi = digitize(ghi, calc_depth, 1/*round*/);
-+ ghi = DU(ghi, calc_depth, 1/*round*/);
-
- b = blo = bhi = that->bluef;
- blo -= that->bluee;
-- blo = digitize(blo, calc_depth, 1/*round*/);
-+ blo = DD(blo, calc_depth, 1/*round*/);
- bhi += that->greene;
-- bhi = digitize(bhi, calc_depth, 1/*round*/);
-+ bhi = DU(bhi, calc_depth, 1/*round*/);
-
- isgray = r==g && g==b;
-
- if (data.gamma != 1)
- {
- PNG_CONST double power = 1/data.gamma;
-- PNG_CONST double abse = calc_depth == 16 ? .5/65535 : .5/255;
-+ PNG_CONST double abse = .5/(sample_depth == 16 ? 65535 : 255);
-
-- /* 'abse' is the absolute error permitted in linear calculations. It
-- * is used here to capture the error permitted in the handling
-- * (undoing) of the gamma encoding. Once again digitization occurs
-- * to handle the upper and lower bounds of the values. This is
-- * where the real errors are introduced.
-+ /* If a gamma calculation is done it is done using lookup tables of
-+ * precision gamma_depth, so the already digitized value above may
-+ * need to be further digitized here.
- */
-+ if (gamma_depth != calc_depth)
-+ {
-+ rlo = DD(rlo, gamma_depth, 0/*truncate*/);
-+ rhi = DU(rhi, gamma_depth, 0/*truncate*/);
-+ glo = DD(glo, gamma_depth, 0/*truncate*/);
-+ ghi = DU(ghi, gamma_depth, 0/*truncate*/);
-+ blo = DD(blo, gamma_depth, 0/*truncate*/);
-+ bhi = DU(bhi, gamma_depth, 0/*truncate*/);
-+ }
-+
-+ /* 'abse' is the error in the gamma table calculation itself. */
- r = pow(r, power);
-- rlo = digitize(pow(rlo, power)-abse, calc_depth, 1);
-- rhi = digitize(pow(rhi, power)+abse, calc_depth, 1);
-+ rlo = DD(pow(rlo, power)-abse, calc_depth, 1);
-+ rhi = DU(pow(rhi, power)+abse, calc_depth, 1);
-
- g = pow(g, power);
-- glo = digitize(pow(glo, power)-abse, calc_depth, 1);
-- ghi = digitize(pow(ghi, power)+abse, calc_depth, 1);
-+ glo = DD(pow(glo, power)-abse, calc_depth, 1);
-+ ghi = DU(pow(ghi, power)+abse, calc_depth, 1);
-
- b = pow(b, power);
-- blo = digitize(pow(blo, power)-abse, calc_depth, 1);
-- bhi = digitize(pow(bhi, power)+abse, calc_depth, 1);
-+ blo = DD(pow(blo, power)-abse, calc_depth, 1);
-+ bhi = DU(pow(bhi, power)+abse, calc_depth, 1);
- }
-
- /* Now calculate the actual gray values. Although the error in the
- * coefficients depends on whether they were specified on the command
- * line (in which case truncation to 15 bits happened) or not (rounding
- * was used) the maxium error in an individual coefficient is always
-- * 1/32768, because even in the rounding case the requirement that
-+ * 2/32768, because even in the rounding case the requirement that
- * coefficients add up to 32768 can cause a larger rounding error.
- *
- * The only time when rounding doesn't occur in 1.5.5 and later is when
-@@ -7185,19 +7305,19 @@ image_transform_png_set_rgb_to_gray_mod(PNG_CONST image_transform *this,
-
- {
- PNG_CONST int do_round = data.gamma != 1 || calc_depth == 16;
-- PNG_CONST double ce = 1. / 32768;
-+ PNG_CONST double ce = 2. / 32768;
-
-- graylo = digitize(rlo * (data.red_coefficient-ce) +
-+ graylo = DD(rlo * (data.red_coefficient-ce) +
- glo * (data.green_coefficient-ce) +
-- blo * (data.blue_coefficient-ce), gamma_depth, do_round);
-- if (graylo <= 0)
-- graylo = 0;
-+ blo * (data.blue_coefficient-ce), calc_depth, do_round);
-+ if (graylo > gray) /* always accept the right answer */
-+ graylo = gray;
-
-- grayhi = digitize(rhi * (data.red_coefficient+ce) +
-+ grayhi = DU(rhi * (data.red_coefficient+ce) +
- ghi * (data.green_coefficient+ce) +
-- bhi * (data.blue_coefficient+ce), gamma_depth, do_round);
-- if (grayhi >= 1)
-- grayhi = 1;
-+ bhi * (data.blue_coefficient+ce), calc_depth, do_round);
-+ if (grayhi < gray)
-+ grayhi = gray;
- }
-
- /* And invert the gamma. */
-@@ -7205,11 +7325,25 @@ image_transform_png_set_rgb_to_gray_mod(PNG_CONST image_transform *this,
- {
- PNG_CONST double power = data.gamma;
-
-+ /* And this happens yet again, shifting the values once more. */
-+ if (gamma_depth != sample_depth)
-+ {
-+ rlo = DD(rlo, gamma_depth, 0/*truncate*/);
-+ rhi = DU(rhi, gamma_depth, 0/*truncate*/);
-+ glo = DD(glo, gamma_depth, 0/*truncate*/);
-+ ghi = DU(ghi, gamma_depth, 0/*truncate*/);
-+ blo = DD(blo, gamma_depth, 0/*truncate*/);
-+ bhi = DU(bhi, gamma_depth, 0/*truncate*/);
-+ }
-+
- gray = pow(gray, power);
-- graylo = digitize(pow(graylo, power), sample_depth, 1);
-- grayhi = digitize(pow(grayhi, power), sample_depth, 1);
-+ graylo = DD(pow(graylo, power), sample_depth, 1);
-+ grayhi = DU(pow(grayhi, power), sample_depth, 1);
- }
-
-+# undef DD
-+# undef DU
-+
- /* Now the error can be calculated.
- *
- * If r==g==b because there is no overall gamma correction libpng
-@@ -7260,16 +7394,28 @@ image_transform_png_set_rgb_to_gray_mod(PNG_CONST image_transform *this,
- {
- /* There is no need to do the conversions to and from linear space,
- * so the calculation should be a lot more accurate. There is a
-- * built in 1/32768 error in the coefficients because they only have
-- * 15 bits and are adjusted to make sure they add up to 32768, so
-- * the result may have an additional error up to 1/32768. (Note
-- * that adding the 1/32768 here avoids needing to increase the
-- * global error limits to take this into account.)
-+ * built in error in the coefficients because they only have 15 bits
-+ * and are adjusted to make sure they add up to 32768. This
-+ * involves a integer calculation with truncation of the form:
-+ *
-+ * ((int)(coefficient * 100000) * 32768)/100000
-+ *
-+ * This is done to the red and green coefficients (the ones
-+ * provided to the API) then blue is calculated from them so the
-+ * result adds up to 32768. In the worst case this can result in
-+ * a -1 error in red and green and a +2 error in blue. Consequently
-+ * the worst case in the calculation below is 2/32768 error.
-+ *
-+ * TODO: consider fixing this in libpng by rounding the calculation
-+ * limiting the error to 1/32768.
-+ *
-+ * Handling this by adding 2/32768 here avoids needing to increase
-+ * the global error limits to take this into account.)
- */
- gray = r * data.red_coefficient + g * data.green_coefficient +
- b * data.blue_coefficient;
- err = re * data.red_coefficient + ge * data.green_coefficient +
-- be * data.blue_coefficient + 1./32768 + gray * 5 * DBL_EPSILON;
-+ be * data.blue_coefficient + 2./32768 + gray * 5 * DBL_EPSILON;
- }
-
- else
-@@ -7304,7 +7450,7 @@ image_transform_png_set_rgb_to_gray_mod(PNG_CONST image_transform *this,
- * previously added input quantization error at this point.
- */
- gray = r * data.red_coefficient + g * data.green_coefficient +
-- b * data.blue_coefficient - 1./32768 - out_qe;
-+ b * data.blue_coefficient - 2./32768 - out_qe;
- if (gray <= 0)
- gray = 0;
- else
-@@ -7314,7 +7460,7 @@ image_transform_png_set_rgb_to_gray_mod(PNG_CONST image_transform *this,
- }
-
- grayhi = rhi * data.red_coefficient + ghi * data.green_coefficient +
-- bhi * data.blue_coefficient + 1./32768 + out_qe;
-+ bhi * data.blue_coefficient + 2./32768 + out_qe;
- grayhi *= (1 + 6 * DBL_EPSILON);
- if (grayhi >= 1)
- grayhi = 1;
-@@ -7429,6 +7575,9 @@ image_transform_png_set_background_set(PNG_CONST image_transform *this,
-
- else
- {
-+ if (that->this.has_tRNS)
-+ that->this.is_transparent = 1;
-+
- bit_depth = that->this.bit_depth;
- expand = 1;
- }
-@@ -7506,14 +7655,14 @@ image_transform_png_set_background_mod(PNG_CONST image_transform *this,
- /* Remove the alpha type and set the alpha (not in that order.) */
- that->alphaf = 1;
- that->alphae = 0;
--
-- if (that->colour_type == PNG_COLOR_TYPE_RGB_ALPHA)
-- that->colour_type = PNG_COLOR_TYPE_RGB;
-- else if (that->colour_type == PNG_COLOR_TYPE_GRAY_ALPHA)
-- that->colour_type = PNG_COLOR_TYPE_GRAY;
-- /* PNG_COLOR_TYPE_PALETTE is not changed */
- }
-
-+ if (that->colour_type == PNG_COLOR_TYPE_RGB_ALPHA)
-+ that->colour_type = PNG_COLOR_TYPE_RGB;
-+ else if (that->colour_type == PNG_COLOR_TYPE_GRAY_ALPHA)
-+ that->colour_type = PNG_COLOR_TYPE_GRAY;
-+ /* PNG_COLOR_TYPE_PALETTE is not changed */
-+
- this->next->mod(this->next, that, pp, display);
- }
-
-@@ -8301,7 +8450,8 @@ perform_transform_test(png_modifier *pm)
- png_byte bit_depth = 0;
- unsigned int palette_number = 0;
-
-- while (next_format(&colour_type, &bit_depth, &palette_number, 0))
-+ while (next_format(&colour_type, &bit_depth, &palette_number, pm->test_lbg,
-+ pm->test_tRNS))
- {
- png_uint_32 counter = 0;
- size_t base_pos;
-@@ -8604,7 +8754,9 @@ init_validate_info(validate_info *vi, gamma_display *dp, png_const_structp pp,
- vi->outlog = outlog(dp->pm, in_depth, out_depth);
-
- if ((dp->this.colour_type & PNG_COLOR_MASK_ALPHA) != 0 ||
-- (dp->this.colour_type == 3 && dp->this.is_transparent))
-+ (dp->this.colour_type == 3 && dp->this.is_transparent) ||
-+ ((dp->this.colour_type == 0 || dp->this.colour_type == 2) &&
-+ dp->this.has_tRNS))
- {
- vi->do_background = dp->do_background;
-
-@@ -8634,7 +8786,7 @@ init_validate_info(validate_info *vi, gamma_display *dp, png_const_structp pp,
- vi->background_blue = b;
- }
- }
-- else
-+ else /* Do not expect any background processing */
- vi->do_background = 0;
-
- if (vi->do_background == 0)
-@@ -9350,6 +9502,7 @@ gamma_image_validate(gamma_display *dp, png_const_structp pp,
- png_uint_32 y;
- PNG_CONST store_palette_entry *in_palette = dp->this.palette;
- PNG_CONST int in_is_transparent = dp->this.is_transparent;
-+ int process_tRNS;
- int out_npalette = -1;
- int out_is_transparent = 0; /* Just refers to the palette case */
- store_palette out_palette;
-@@ -9365,6 +9518,7 @@ gamma_image_validate(gamma_display *dp, png_const_structp pp,
-
- processing = (vi.gamma_correction > 0 && !dp->threshold_test)
- || in_bd != out_bd || in_ct != out_ct || vi.do_background;
-+ process_tRNS = dp->this.has_tRNS && vi.do_background;
-
- /* TODO: FIX THIS: MAJOR BUG! If the transformations all happen inside
- * the palette there is no way of finding out, because libpng fails to
-@@ -9403,8 +9557,8 @@ gamma_image_validate(gamma_display *dp, png_const_structp pp,
- /* Handle input alpha - png_set_background will cause the output
- * alpha to disappear so there is nothing to check.
- */
-- if ((in_ct & PNG_COLOR_MASK_ALPHA) != 0 || (in_ct == 3 &&
-- in_is_transparent))
-+ if ((in_ct & PNG_COLOR_MASK_ALPHA) != 0 ||
-+ (in_ct == 3 && in_is_transparent))
- {
- PNG_CONST unsigned int input_alpha = in_ct == 3 ?
- dp->this.palette[in_index].alpha :
-@@ -9436,6 +9590,35 @@ gamma_image_validate(gamma_display *dp, png_const_structp pp,
- }
- }
-
-+ else if (process_tRNS)
-+ {
-+ /* alpha needs to be set appropriately for this pixel, it is
-+ * currently 1 and needs to be 0 for an input pixel which matches
-+ * the values in tRNS.
-+ */
-+ switch (in_ct)
-+ {
-+ case 0: /* gray */
-+ if (sample(std, in_ct, in_bd, x, 0, 0, 0) ==
-+ dp->this.transparent.red)
-+ alpha = 0;
-+ break;
-+
-+ case 2: /* RGB */
-+ if (sample(std, in_ct, in_bd, x, 0, 0, 0) ==
-+ dp->this.transparent.red &&
-+ sample(std, in_ct, in_bd, x, 1, 0, 0) ==
-+ dp->this.transparent.green &&
-+ sample(std, in_ct, in_bd, x, 2, 0, 0) ==
-+ dp->this.transparent.blue)
-+ alpha = 0;
-+ break;
-+
-+ default:
-+ break;
-+ }
-+ }
-+
- /* Handle grayscale or RGB components. */
- if ((in_ct & PNG_COLOR_MASK_COLOR) == 0) /* grayscale */
- (void)gamma_component_validate("gray", &vi,
-@@ -9545,7 +9728,7 @@ gamma_test(png_modifier *pmIn, PNG_CONST png_byte colour_typeIn,
-
- modification_reset(d.pm->modifications);
-
-- /* Get a png_struct for writing the image. */
-+ /* Get a png_struct for reading the image. */
- pp = set_modifier_for_read(d.pm, &pi, d.this.id, name);
- standard_palette_init(&d.this);
-
-@@ -9684,9 +9867,13 @@ perform_gamma_threshold_tests(png_modifier *pm)
- /* Don't test more than one instance of each palette - it's pointless, in
- * fact this test is somewhat excessive since libpng doesn't make this
- * decision based on colour type or bit depth!
-+ *
-+ * CHANGED: now test two palettes and, as a side effect, images with and
-+ * without tRNS.
- */
-- while (next_format(&colour_type, &bit_depth, &palette_number, 1/*gamma*/))
-- if (palette_number == 0)
-+ while (next_format(&colour_type, &bit_depth, &palette_number,
-+ pm->test_lbg_gamma_threshold, pm->test_tRNS))
-+ if (palette_number < 2)
- {
- double test_gamma = 1.0;
- while (test_gamma >= .4)
-@@ -9746,7 +9933,8 @@ static void perform_gamma_transform_tests(png_modifier *pm)
- png_byte bit_depth = 0;
- unsigned int palette_number = 0;
-
-- while (next_format(&colour_type, &bit_depth, &palette_number, 1/*gamma*/))
-+ while (next_format(&colour_type, &bit_depth, &palette_number,
-+ pm->test_lbg_gamma_transform, pm->test_tRNS))
- {
- unsigned int i, j;
-
-@@ -9776,7 +9964,8 @@ static void perform_gamma_sbit_tests(png_modifier *pm)
- png_byte colour_type = 0, bit_depth = 0;
- unsigned int npalette = 0;
-
-- while (next_format(&colour_type, &bit_depth, &npalette, 1/*gamma*/))
-+ while (next_format(&colour_type, &bit_depth, &npalette,
-+ pm->test_lbg_gamma_sbit, pm->test_tRNS))
- if ((colour_type & PNG_COLOR_MASK_ALPHA) == 0 &&
- ((colour_type == 3 && sbit < 8) ||
- (colour_type != 3 && sbit < bit_depth)))
-@@ -9967,8 +10156,17 @@ static void gamma_composition_test(png_modifier *pm,
- }
-
- background.index = 193; /* rgb(193,193,193) to detect errors */
-+
- if (!(colour_type & PNG_COLOR_MASK_COLOR))
- {
-+ /* Because, currently, png_set_background is always called with
-+ * 'need_expand' false in this case and because the gamma test itself
-+ * doesn't cause an expand to 8-bit for lower bit depths the colour must
-+ * be reduced to the correct range.
-+ */
-+ if (bit_depth < 8)
-+ background.gray &= (png_uint_16)((1U << bit_depth)-1);
-+
- /* Grayscale input, we do not convert to RGB (TBD), so we must set the
- * background to gray - else libpng seems to fail.
- */
-@@ -10017,9 +10215,18 @@ perform_gamma_composition_tests(png_modifier *pm, int do_background,
-
- /* Skip the non-alpha cases - there is no setting of a transparency colour at
- * present.
-- */
-- while (next_format(&colour_type, &bit_depth, &palette_number, 1/*gamma*/))
-- if ((colour_type & PNG_COLOR_MASK_ALPHA) != 0)
-+ *
-+ * TODO: incorrect; the palette case sets tRNS and, now RGB and gray do,
-+ * however the palette case fails miserably so is commented out below.
-+ */
-+ while (next_format(&colour_type, &bit_depth, &palette_number,
-+ pm->test_lbg_gamma_composition, pm->test_tRNS))
-+ if ((colour_type & PNG_COLOR_MASK_ALPHA) != 0
-+#if 0 /* TODO: FIXME */
-+ /*TODO: FIXME: this should work */
-+ || colour_type == 3
-+#endif
-+ || (colour_type != 3 && palette_number != 0))
- {
- unsigned int i, j;
-
-@@ -10751,6 +10958,18 @@ int main(int argc, char **argv)
- pm.ngammas = ARRAY_SIZE(gammas);
- pm.ngamma_tests = 0; /* default to off */
-
-+ /* Low bit depth gray images don't do well in the gamma tests, until
-+ * this is fixed turn them off for some gamma cases:
-+ */
-+# ifdef PNG_WRITE_tRNS_SUPPORTED
-+ pm.test_tRNS = 1;
-+# endif
-+ pm.test_lbg = 0;
-+ pm.test_lbg_gamma_threshold = 1;
-+ pm.test_lbg_gamma_transform = 0/*PNG_LIBPNG_VER >= 10700*/;
-+ pm.test_lbg_gamma_sbit = 1;
-+ pm.test_lbg_gamma_composition = 0;
-+
- /* And the test encodings */
- pm.encodings = test_encodings;
- pm.nencodings = ARRAY_SIZE(test_encodings);
-@@ -10863,7 +11082,7 @@ int main(int argc, char **argv)
- pm.test_gamma_transform = 1;
- pm.test_gamma_sbit = 1;
- pm.test_gamma_scale16 = 1;
-- pm.test_gamma_background = 1;
-+ pm.test_gamma_background = 1; /* composition */
- pm.test_gamma_alpha_mode = 1;
- }
-
-@@ -10912,6 +11131,24 @@ int main(int argc, char **argv)
- else if (strcmp(*argv, "--noexpand16") == 0)
- pm.test_gamma_expand16 = 0;
-
-+ else if (strcmp(*argv, "--low-depth-gray") == 0)
-+ pm.test_lbg = pm.test_lbg_gamma_threshold =
-+ pm.test_lbg_gamma_transform = pm.test_lbg_gamma_sbit =
-+ pm.test_lbg_gamma_composition = 1;
-+
-+ else if (strcmp(*argv, "--nolow-depth-gray") == 0)
-+ pm.test_lbg = pm.test_lbg_gamma_threshold =
-+ pm.test_lbg_gamma_transform = pm.test_lbg_gamma_sbit =
-+ pm.test_lbg_gamma_composition = 0;
-+
-+# ifdef PNG_WRITE_tRNS_SUPPORTED
-+ else if (strcmp(*argv, "--tRNS") == 0)
-+ pm.test_tRNS = 1;
-+# endif
-+
-+ else if (strcmp(*argv, "--notRNS") == 0)
-+ pm.test_tRNS = 0;
-+
- else if (strcmp(*argv, "--more-gammas") == 0)
- pm.ngamma_tests = 3U;
-
-@@ -11102,7 +11339,7 @@ int main(int argc, char **argv)
- Try
- {
- /* Make useful base images */
-- make_transform_images(&pm.this);
-+ make_transform_images(&pm);
-
- /* Perform the standard and gamma tests. */
- if (pm.test_standard)
projects / packages / libpng.git / commitdiff