mewin/libpng
1
0
Fork 0
mirror of https://git.code.sf.net/p/libpng/code.git synced 2025-07-10 18:04:09 +02:00
Code Issues Projects Releases Wiki Activity

[libpng15] Installed more accurate linear to sRGB conversion tables.

Browse Source 
The slightly modified tables reduce the number of 16-bit values that
convert to an off-by-one 8-bit value.  The "makesRGB.c" code that was used
to generate the tables is now in a contrib/sRGBtables sub-directory.
This commit is contained in:
John Bowler 2011-11-11 18:14:59 -06:00 committed by Glenn Randers-Pehrson
parent d3feb52955
commit 0a521d3785
4 changed files with 519 additions and 216 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

8
ANNOUNCE
View File

@ -1,5 +1,5 @@
Libpng 1.5.7beta02 - November 8, 2011
Libpng 1.5.7beta02 - November 12, 2011
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.
@ -43,7 +43,7 @@ Version 1.5.7beta01 [November 4, 2011]
just the changes that definitely improve speed and remain simple.
The changes also slightly increase the clarity of the code.
Version 1.5.7beta02 [November 8, 2011]
Version 1.5.7beta02 [November 12, 2011]
Check compression_type parameter in png_get_iCCP and remove spurious
casts. The compression_type parameter is always assigned to, so must
be non-NULL. The cast of the profile length potentially truncated the
@ -60,6 +60,10 @@ Version 1.5.7beta02 [November 8, 2011]
Added versioning to pnglibconf.h comments.
Simplified read/write API initial version; basic read/write tested on
a variety of images, limited documentation (in the header file.)
Installed more accurate linear to sRGB conversion tables. The slightly
modified tables reduce the number of 16-bit values that
convert to an off-by-one 8-bit value. The "makesRGB.c" code that was used
to generate the tables is now in a contrib/sRGBtables sub-directory.
Send comments/corrections/commendations to png-mng-implement at lists.sf.net:
(subscription required; visit

6
CHANGES
View File

@ -3688,7 +3688,7 @@ Version 1.5.7beta01 [November 4, 2011]
just the changes that definitely improve speed and remain simple.
The changes also slightly increase the clarity of the code.
Version 1.5.7beta02 [November 8, 2011]
Version 1.5.7beta02 [November 12, 2011]
Check compression_type parameter in png_get_iCCP and remove spurious
casts. The compression_type parameter is always assigned to, so must
be non-NULL. The cast of the profile length potentially truncated the
@ -3705,6 +3705,10 @@ Version 1.5.7beta02 [November 8, 2011]
Added versioning to pnglibconf.h comments.
Simplified read/write API initial version; basic read/write tested on
a variety of images, limited documentation (in the header file.)
Installed more accurate linear to sRGB conversion tables. The slightly
modified tables reduce the number of 16-bit values that
convert to an off-by-one 8-bit value. The "makesRGB.c" code that was used
to generate the tables is now in a contrib/sRGBtables sub-directory.
Send comments/corrections/commendations to png-mng-implement at lists.sf.net
(subscription required; visit

451
contrib/sRGBtables/makesRGB.c Normal file
View File

@ -0,0 +1,451 @@
/*-
* makesRGB.c
*
* Make a table to convert 8-bit sRGB encoding values into the closest 16-bit
* linear value.
*
* Make two tables to take a linear value scaled to 255*65535 and return an
* approximation to the 8-bit sRGB encoded value. Calculate the error in these
* tables and display it.
*/
#define _C99_SOURCE 1
#include <stdio.h>
#include <math.h>
#include <stdlib.h>
/* pngpriv.h includes the definition of 'PNG_sRGB_FROM_LINEAR' which is required
* to verify the actual code.
*/
#include "../pngpriv.h"
/*
* Utility sRGB calculation functions.
*
* Both routines take and return a floating point value in the range 0 to 1.0,
* doing a calculation according to the sRGB specification. (In fact the source
* of the numbers is the wikipedia article.)
*/
double
sRGB_from_linear(double l)
{
if (l <= 0.0031308)
l *= 12.92;
else
l = 1.055 * pow(l, 1/2.4) - 0.055;
return l;
}
double
linear_from_sRGB(double s)
{
if (s <= 0.04045)
return s / 12.92;
else
return pow((s+0.055)/1.055, 2.4);
}
/* The tables are declared 'const' in pngpriv.h, so this redefines the tables to
* be used.
*/
#define png_sRGB_table sRGB_table
#define png_sRGB_base sRGB_base
#define png_sRGB_delta sRGB_delta
static png_uint_16 png_sRGB_table[256];
static png_uint_16 png_sRGB_base[512];
static png_byte png_sRGB_delta[512];
static const unsigned int max_input = 255*65535;
double
fsRGB(double l)
{
return sRGB_from_linear(l/max_input);
}
double
sRGB(unsigned int i)
{
return fsRGB(i);
}
double
finvsRGB(unsigned int i)
{
return 65535 * linear_from_sRGB(i/255.);
}
png_uint_16
invsRGB(unsigned int i)
{
unsigned int x = nearbyint(finvsRGB(i));
if (x > 65535)
{
fprintf(stderr, "invsRGB(%u) overflows to %u\n", i, x);
exit(1);
}
return (png_uint_16)x;
}
int
main(int argc, char **argv)
{
unsigned int i, i16, ibase;
double min_error = 0;
double max_error = 0;
double min_error16 = 0;
double max_error16 = 0;
double adjust;
double adjust_lo = 0.4, adjust_hi = 0.6, adjust_mid = 0.5;
unsigned int ec_lo = 0, ec_hi = 0, ec_mid = 0;
unsigned int error_count = 0;
unsigned int error_count16 = 0;
int test_only = 0;
if (argc > 1)
test_only = strcmp("--test", argv[1]) == 0;
/* Initialize the encoding table first. */
for (i=0; i<256; ++i)
{
png_sRGB_table[i] = invsRGB(i);
}
/* Now work out the decoding tables (this is where the error comes in because
* there are 512 set points and 512 straight lines between them.)
*/
for (;;)
{
if (ec_lo == 0)
adjust = adjust_lo;
else if (ec_hi == 0)
adjust = adjust_hi;
else if (ec_mid == 0)
adjust = adjust_mid;
else if (ec_mid < ec_hi)
adjust = (adjust_mid + adjust_hi)/2;
else if (ec_mid < ec_lo)
adjust = (adjust_mid + adjust_lo)/2;
else
{
fprintf(stderr, "not reached: %u .. %u .. %u\n", ec_lo, ec_mid, ec_hi);
exit(1);
}
/* Calculate the table using the current 'adjust' */
for (i=0; i<=511; ++i)
{
double lo = 255 * sRGB(i << 15);
double hi = 255 * sRGB((i+1) << 15);
unsigned int calc;
calc = nearbyint((lo+adjust) * 256);
if (calc > 65535)
{
fprintf(stderr, "table[%d][0]: overflow %08x (%d)\n", i, calc,
calc);
exit(1);
}
png_sRGB_base[i] = calc;
calc = nearbyint((hi-lo) * 32);
if (calc > 255)
{
fprintf(stderr, "table[%d][1]: overflow %08x (%d)\n", i, calc,
calc);
exit(1);
}
png_sRGB_delta[i] = calc;
}
/* Check the 16-bit linear values alone: */
error_count16 = 0;
for (i16=0; i16 <= 65535; ++i16)
{
unsigned int i = 255*i16;
unsigned int iexact = nearbyint(255*sRGB(i));
unsigned int icalc = PNG_sRGB_FROM_LINEAR(i);
if (icalc != iexact)
++error_count16;
}
/* Now try changing the adjustment. */
if (ec_lo == 0)
ec_lo = error_count16;
else if (ec_hi == 0)
ec_hi = error_count16;
else if (ec_mid == 0)
{
ec_mid = error_count16;
printf("/* initial error counts: %u .. %u .. %u */\n", ec_lo, ec_mid,
ec_hi);
}
else if (error_count16 < ec_mid)
{
printf("/* adjust (mid ): %f: %u -> %u */\n", adjust, ec_mid,
error_count16);
ec_mid = error_count16;
adjust_mid = adjust;
}
else if (adjust < adjust_mid && error_count16 < ec_lo)
{
printf("/* adjust (low ): %f: %u -> %u */\n", adjust, ec_lo,
error_count16);
ec_lo = error_count16;
adjust_lo = adjust;
}
else if (adjust > adjust_mid && error_count16 < ec_hi)
{
printf("/* adjust (high): %f: %u -> %u */\n", adjust, ec_hi,
error_count16);
ec_hi = error_count16;
adjust_hi = adjust;
}
else
{
adjust = adjust_mid;
printf("/* adjust: %f: %u */\n", adjust, ec_mid);
break;
}
}
/* For each entry in the table try to adjust it to minimize the error count
* in that entry. Each entry corresponds to 128 input values.
*/
for (ibase=0; ibase<65536; ibase+=128)
{
png_uint_16 base = png_sRGB_base[ibase >> 7], trybase = base, ob=base;
png_byte delta = png_sRGB_delta[ibase >> 7], trydelta = delta, od=delta;
unsigned int ecbase = 0, eco;
for (;;)
{
png_sRGB_base[ibase >> 7] = trybase;
png_sRGB_delta[ibase >> 7] = trydelta;
/* Check the 16-bit linear values alone: */
error_count16 = 0;
for (i16=ibase; i16 < ibase+128; ++i16)
{
unsigned int i = 255*i16;
unsigned int iexact = nearbyint(255*sRGB(i));
unsigned int icalc = PNG_sRGB_FROM_LINEAR(i);
if (icalc != iexact)
++error_count16;
}
if (error_count16 == 0)
break;
if (ecbase == 0)
{
eco = ecbase = error_count16;
++trybase; /* First test */
}
else if (error_count16 < ecbase)
{
if (trybase > base)
{
base = trybase;
++trybase;
}
else if (trybase < base)
{
base = trybase;
--trybase;
}
else if (trydelta > delta)
{
delta = trydelta;
++trydelta;
}
else if (trydelta < delta)
{
delta = trydelta;
--trydelta;
}
else
{
fprintf(stderr, "makesRGB: impossible\n");
exit(1);
}
ecbase = error_count16;
}
else
{
if (trybase > base)
trybase = base-1;
else if (trybase < base)
{
trybase = base;
++trydelta;
}
else if (trydelta > delta)
trydelta = delta-1;
else if (trydelta < delta)
break; /* end of tests */
}
}
png_sRGB_base[ibase >> 7] = base;
png_sRGB_delta[ibase >> 7] = delta;
if (base != ob || delta != od)
{
printf("/* table[%u]={%u,%u} -> {%u,%u} %u -> %u errors */\n",
ibase>>7, ob, od, base, delta, eco, ecbase);
}
else if (0)
printf("/* table[%u]={%u,%u} %u errors */\n", ibase>>7, ob, od,
ecbase);
}
/* Only do the full (slow) test at the end: */
min_error = -.4999;
max_error = .4999;
error_count = 0;
for (i=0; i <= max_input; ++i)
{
unsigned int iexact = nearbyint(255*sRGB(i));
unsigned int icalc = PNG_sRGB_FROM_LINEAR(i);
if (icalc != iexact)
{
double err = 255*sRGB(i) - icalc;
if (err > (max_error+.001) || err < (min_error-.001))
{
printf(
"/* 0x%08x: exact: %3d, got: %3d [tables: %08x, %08x] (%f) */\n",
i, iexact, icalc, png_sRGB_base[i>>15],
png_sRGB_delta[i>>15], err);
}
++error_count;
if (err > max_error)
max_error = err;
else if (err < min_error)
min_error = err;
}
}
/* Re-check the 16-bit cases too, including the warning if there is an error
* bigger than 1.
*/
error_count16 = 0;
max_error16 = 0;
min_error16 = 0;
for (i16=0; i16 <= 65535; ++i16)
{
unsigned int i = 255*i16;
unsigned int iexact = nearbyint(255*sRGB(i));
unsigned int icalc = PNG_sRGB_FROM_LINEAR(i);
if (icalc != iexact)
{
double err = 255*sRGB(i) - icalc;
++error_count16;
if (err > max_error16)
max_error16 = err;
else if (err < min_error16)
min_error16 = err;
if (abs(icalc - iexact) > 1)
printf(
"/* 0x%04x: exact: %3d, got: %3d [tables: %08x, %08x] (%f) */\n",
i16, iexact, icalc, png_sRGB_base[i>>15],
png_sRGB_delta[i>>15], err);
}
}
/* Check the round trip for each 8-bit sRGB value. */
for (i16=0; i16 <= 255; ++i16)
{
unsigned int i = 255 * png_sRGB_table[i16];
unsigned int iexact = nearbyint(255*sRGB(i));
unsigned int icalc = PNG_sRGB_FROM_LINEAR(i);
if (i16 != iexact)
{
fprintf(stderr, "8-bit rounding error: %d -> %d\n", i16, iexact);
exit(1);
}
if (icalc != i16)
{
double finv = finvsRGB(i16);
printf("/* 8-bit roundtrip error: %d -> %f -> %d(%f) */\n",
i16, finv, icalc, fsRGB(255*finv));
}
}
printf("/* error: %g - %g, %u (%g%%) of readings inexact */\n",
min_error, max_error, error_count, (100.*error_count)/max_input);
printf("/* 16-bit error: %g - %g, %u (%g%%) of readings inexact */\n",
min_error16, max_error16, error_count16, (100.*error_count16)/65535);
if (!test_only)
{
printf("PNG_CONST png_uint_16 png_sRGB_table[256] =\n{\n ");
for (i=0; i<255; )
{
do
{
printf("%d,", png_sRGB_table[i++]);
}
while ((i & 0x7) != 0 && i<255);
if (i<255) printf("\n ");
}
printf("%d\n};\n\n", png_sRGB_table[i]);
printf("PNG_CONST png_uint_16 png_sRGB_base[512] =\n{\n ");
for (i=0; i<511; )
{
do
{
printf("%d,", png_sRGB_base[i++]);
}
while ((i & 0x7) != 0 && i<511);
if (i<511) printf("\n ");
}
printf("%d\n};\n\n", png_sRGB_base[i]);
printf("PNG_CONST png_byte png_sRGB_delta[512] =\n{\n ");
for (i=0; i<511; )
{
do
{
printf("%d,", png_sRGB_delta[i++]);
}
while ((i & 0xf) != 0 && i<511);
if (i<511) printf("\n ");
}
printf("%d\n};\n\n", png_sRGB_delta[i]);
}
return 0;
}

270
png.c
View File

@ -645,13 +645,13 @@ png_get_copyright(png_const_structp png_ptr)
#else
# ifdef __STDC__
return PNG_STRING_NEWLINE \
"libpng version 1.5.7beta02 - November 10, 2011" PNG_STRING_NEWLINE \
"libpng version 1.5.7beta02 - November 12, 2011" PNG_STRING_NEWLINE \
"Copyright (c) 1998-2011 Glenn Randers-Pehrson" PNG_STRING_NEWLINE \
"Copyright (c) 1996-1997 Andreas Dilger" PNG_STRING_NEWLINE \
"Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc." \
PNG_STRING_NEWLINE;
# else
return "libpng version 1.5.7beta02 - November 10, 2011\
return "libpng version 1.5.7beta02 - November 12, 2011\
Copyright (c) 1998-2011 Glenn Randers-Pehrson\
Copyright (c) 1996-1997 Andreas Dilger\
Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.";
@ -2858,173 +2858,21 @@ png_build_gamma_table(png_structp png_ptr, int bit_depth)
/* sRGB support */
#if defined PNG_SIMPLIFIED_READ_SUPPORTED ||\
defined PNG_SIMPLIFIED_WRITE_SUPPORTED
/* sRGB conversion tables; these are machine generated with the following code.
/* sRGB conversion tables; these are machine generated with the code in
* contrib/sRGBtables/makesRGB.c. The sRGB to linear table is exact (to the
* nearest 16 bit linear fraction). The inverse (linear to sRGB) table has
* accuracies as follows:
*
* For all possible (255*65535+1) input values:
*
* error: -0.515566 - 0.625971, 79441 (0.475369%) of readings inexact
*
* For the input values corresponding to the 65536 16-bit values:
*
* error: -0.513727 - 0.607759, 308 (0.469978%) of readings inexact
*
* In all cases the inexact readings are off by one.
*/
#ifdef PNG_INCLUDE_SELF_GENERATING_AND_SELF_DOCUMENTING_CODE
#define _C99_SOURCE 1
#include <stdio.h>
#include <math.h>
#include <stdlib.h>
static unsigned int max_input = 255*65535;
double sRGB(unsigned int i)
{
double l = i;
l /= max_input;
if (l <= 0.0031308)
l *= 12.92;
else
l = 1.055 * pow(l, 1/2.4) - 0.055;
return l;
}
unsigned int invsRGB(unsigned int i)
{
double l = i/255.;
if (l <= 0.04045)
l /= 12.92;
else
l = pow((l+0.055)/1.055, 2.4);
l *= 65535;
return nearbyint(l);
}
int main(void)
{
unsigned int i, i16;
unsigned short base[512];
unsigned char delta[512];
double max_error = 0;
double max_error16 = 0;
unsigned int error_count = 0;
unsigned int error_count16 = 0;
for (i=0; i<=511; ++i)
{
double lo = 255 * sRGB(i << 15);
double hi = 255 * sRGB((i+1) << 15);
unsigned int calc;
calc = nearbyint((lo+.5) * 256);
if (calc > 65535)
{
fprintf(stderr, "table[%d][0]: overflow %08x (%d)\n", i, calc, calc);
exit(1);
}
base[i] = calc;
calc = nearbyint((hi-lo) * 32);
if (calc > 255)
{
fprintf(stderr, "table[%d][1]: overflow %08x (%d)\n", i, calc, calc);
exit(1);
}
delta[i] = calc;
}
for (i=0; i <= max_input; ++i)
{
unsigned int iexact = nearbyint(255*sRGB(i));
unsigned int icalc = base[i>>15] + (((i&0x7fff)*delta[i>>15])>>12);
icalc >>= 8;
if (icalc != iexact)
{
double err = fabs(255*sRGB(i) - icalc);
++error_count;
if (err > .646)
{
printf(
"/* 0x%08x: exact: %3d, got: %3d [tables: %08x, %08x] (%f) */\n",
i, iexact, icalc, base[i>>15], delta[i>>15], err);
if (err > max_error)
max_error = err;
}
}
}
for (i16=0; i16 <= 65535; ++i16)
{
unsigned int i = 255*i16;
unsigned int iexact = nearbyint(255*sRGB(i));
unsigned int icalc = base[i>>15] + (((i&0x7fff)*delta[i>>15])>>12);
icalc >>= 8;
if (icalc != iexact)
{
double err = fabs(255*sRGB(i) - icalc);
++error_count16;
if (err > max_error16)
max_error16 = err;
if (abs(icalc - iexact) > 1)
printf(
"/* 0x%04x: exact: %3d, got: %3d [tables: %08x, %08x] (%f) */\n",
i16, iexact, icalc, base[i>>15], delta[i>>15], err);
}
}
printf("/* maximum error: %g, %g%% of readings */\n", max_error,
(100.*error_count)/max_input);
printf("/* maximum 16-bit error: %g, %g%% of readings */\n", max_error16,
(100.*error_count16)/65535);
printf("PNG_CONST png_uint_16 png_sRGB_table[256] =\n{\n ");
for (i=0; i<255; )
{
do
{
printf("%d,", invsRGB(i++));
}
while ((i & 0x7) != 0 && i<255);
if (i<255) printf("\n ");
}
printf("%d\n};\n\n", invsRGB(i));
printf("PNG_CONST png_uint_16 png_sRGB_base[512] =\n{\n ");
for (i=0; i<511; )
{
do
{
printf("%d,", base[i++]);
}
while ((i & 0x7) != 0 && i<511);
if (i<511) printf("\n ");
}
printf("%d\n};\n\n", base[i]);
printf("PNG_CONST png_byte png_sRGB_delta[512] =\n{\n ");
for (i=0; i<511; )
{
do
{
printf("%d,", delta[i++]);
}
while ((i & 0xf) != 0 && i<511);
if (i<511) printf("\n ");
}
printf("%d\n};\n\n", delta[i]);
return 0;
}
#endif /* self documenting code */
/* The result is a set of tables with the following errors: */
/* 0x000148c1: exact: 16, got: 15 [tables: 00000d36, 0000009d] (0.646071) */
/* 0x000148c2: exact: 16, got: 15 [tables: 00000d36, 0000009d] (0.646218) */
/* 0x000148c3: exact: 16, got: 15 [tables: 00000d36, 0000009d] (0.646365) */
/* maximum error: 0.646365, 0.494416% of readings */
/* maximum 16-bit error: 0.644455, 0.5066% of readings */
#ifdef PNG_SIMPLIFIED_READ_SUPPORTED
/* The convert-to-sRGB table is only currently required for read. */
@ -3063,6 +2911,7 @@ PNG_CONST png_uint_16 png_sRGB_table[256] =
57105,57646,58190,58737,59287,59840,60396,60955,
61517,62082,62650,63221,63795,64372,64952,65535
};
#endif /* simplified read only */
/* The base/delta tables are required for both read and write (but currently
@ -3070,52 +2919,52 @@ PNG_CONST png_uint_16 png_sRGB_table[256] =
*/
PNG_CONST png_uint_16 png_sRGB_base[512] =
{
128,1782,3382,4641,5673,6563,7355,8072,
8732,9346,9920,10463,10977,11466,11935,12384,
12815,13232,13634,14024,14402,14768,15125,15473,
15811,16142,16465,16781,17090,17393,17689,17980,
128,1782,3383,4644,5675,6564,7357,8074,
8732,9346,9921,10463,10977,11466,11935,12384,
12816,13233,13634,14024,14402,14769,15125,15473,
15812,16142,16466,16781,17090,17393,17690,17981,
18266,18546,18822,19093,19359,19621,19879,20133,
20383,20630,20873,21113,21349,21583,21813,22040,
22265,22487,22706,22923,23138,23350,23559,23767,
20383,20630,20873,21113,21349,21583,21813,22041,
22265,22487,22707,22923,23138,23350,23559,23767,
23972,24175,24376,24575,24772,24967,25160,25352,
25541,25729,25916,26100,26283,26465,26645,26823,
27000,27176,27350,27523,27694,27865,28033,28201,
25542,25730,25916,26101,26284,26465,26645,26823,
27000,27176,27350,27523,27695,27865,28034,28201,
28368,28533,28697,28860,29021,29182,29341,29500,
29657,29813,29969,30123,30276,30428,30580,30730,
29657,29813,29969,30123,30276,30429,30580,30730,
30880,31028,31176,31323,31469,31614,31758,31902,
32044,32186,32327,32468,32607,32746,32884,33021,
33158,33294,33429,33563,33697,33830,33963,34095,
34226,34356,34486,34616,34744,34872,35000,35127,
32045,32186,32327,32468,32607,32746,32884,33021,
33158,33294,33429,33564,33697,33831,33963,34095,
34226,34357,34486,34616,34744,34873,35000,35127,
35253,35379,35504,35629,35753,35876,35999,36122,
36244,36365,36486,36606,36726,36845,36964,37083,
37201,37318,37435,37551,37667,37783,37898,38013,
37201,37318,37435,37551,37668,37783,37898,38013,
38127,38241,38354,38467,38580,38692,38803,38915,
39025,39136,39246,39356,39465,39574,39682,39790,
39026,39136,39246,39356,39465,39574,39682,39790,
39898,40005,40112,40219,40325,40431,40537,40642,
40747,40851,40955,41059,41163,41266,41369,41471,
41573,41675,41776,41878,41978,42079,42179,42279,
42379,42478,42577,42676,42774,42873,42970,43068,
43165,43262,43359,43455,43552,43647,43743,43838,
43934,44028,44123,44217,44311,44405,44498,44592,
44685,44777,44870,44962,45054,45146,45238,45329,
41573,41675,41777,41878,41979,42079,42179,42279,
42379,42478,42577,42676,42775,42873,42971,43068,
43165,43262,43359,43456,43552,43648,43743,43839,
43934,44028,44123,44217,44311,44405,44499,44592,
44685,44778,44870,44962,45054,45146,45238,45329,
45420,45511,45601,45692,45782,45872,45961,46051,
46140,46229,46318,46406,46494,46582,46670,46758,
46845,46933,47020,47107,47193,47280,47366,47452,
47538,47623,47708,47794,47879,47963,48048,48132,
48217,48301,48384,48468,48552,48635,48718,48801,
48884,48966,49048,49131,49213,49294,49376,49457,
49539,49620,49701,49781,49862,49942,50023,50103,
50183,50262,50342,50421,50501,50580,50659,50738,
50816,50895,50973,51051,51129,51207,51284,51362,
51439,51517,51594,51670,51747,51824,51900,51977,
52053,52129,52205,52280,52356,52431,52507,52582,
46140,46229,46318,46406,46494,46583,46670,46758,
46846,46933,47020,47107,47193,47280,47366,47452,
47538,47623,47709,47794,47879,47964,48048,48133,
48217,48301,48385,48468,48552,48635,48718,48801,
48884,48966,49048,49131,49213,49294,49376,49458,
49539,49620,49701,49782,49862,49943,50023,50103,
50183,50263,50342,50422,50501,50580,50659,50738,
50816,50895,50973,51051,51129,51207,51285,51362,
51439,51517,51594,51671,51747,51824,51900,51977,
52053,52129,52205,52280,52356,52432,52507,52582,
52657,52732,52807,52881,52956,53030,53104,53178,
53252,53326,53399,53473,53546,53620,53693,53766,
53252,53326,53400,53473,53546,53620,53693,53766,
53839,53911,53984,54056,54129,54201,54273,54345,
54417,54489,54560,54632,54703,54774,54845,54916,
54987,55058,55128,55199,55269,55340,55410,55480,
55550,55619,55689,55759,55828,55897,55967,56036,
56105,56174,56242,56311,56380,56448,56516,56585,
54987,55058,55129,55199,55269,55340,55410,55480,
55550,55620,55689,55759,55828,55898,55967,56036,
56105,56174,56243,56311,56380,56448,56517,56585,
56653,56721,56789,56857,56924,56992,57059,57127,
57194,57261,57328,57395,57462,57529,57595,57662,
57728,57795,57861,57927,57993,58059,58125,58191,
@ -3126,22 +2975,22 @@ PNG_CONST png_uint_16 png_sRGB_base[512] =
60308,60370,60433,60495,60558,60620,60682,60744,
60806,60868,60930,60992,61054,61115,61177,61238,
61300,61361,61422,61483,61544,61605,61666,61727,
61788,61848,61909,61969,62030,62090,62150,62210,
61788,61848,61909,61969,62030,62090,62150,62211,
62271,62331,62391,62450,62510,62570,62630,62689,
62749,62808,62867,62927,62986,63045,63104,63163,
63222,63281,63339,63398,63457,63515,63574,63632,
63222,63281,63340,63398,63457,63515,63574,63632,
63691,63749,63807,63865,63923,63981,64039,64097,
64155,64212,64270,64328,64385,64442,64500,64557,
64614,64671,64729,64786,64843,64899,64956,65013,
65070,65126,65183,65239,65296,65352,65408,65465
64155,64212,64270,64328,64385,64443,64500,64557,
64614,64672,64729,64786,64843,64900,64956,65013,
65070,65126,65183,65239,65296,65352,65409,65465
};
PNG_CONST png_byte png_sRGB_delta[512] =
{
207,200,157,129,111,99,90,82,77,72,68,64,61,59,56,54,
207,201,158,129,113,100,90,82,77,72,68,64,61,59,56,54,
52,50,49,47,46,45,43,42,41,40,39,39,38,37,36,36,
35,34,34,33,33,32,32,31,31,30,30,30,29,29,28,28,
28,27,27,27,26,26,26,26,25,25,25,25,24,24,24,24,
28,27,27,27,27,26,26,26,25,25,25,25,24,24,24,24,
23,23,23,23,23,22,22,22,22,22,22,21,21,21,21,21,
21,20,20,20,20,20,20,20,20,19,19,19,19,19,19,19,
19,18,18,18,18,18,18,18,18,18,18,17,17,17,17,17,
@ -3171,11 +3020,6 @@ PNG_CONST png_byte png_sRGB_delta[512] =
7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7
};
/* Hence the define in pngpriv.h to calculate the sRGB value of a linear value
* expressed as a fixed point integer scaled by 255*65535 (note that the tables
* include the +.5 to do rounding correctly.)
*/
#endif /* SIMPLIFIED READ/WRITE sRGB support */
/* SIMPLIFIED READ/WRITE SUPPORT */