4 * Copyright (c) 2013-2016 John Cunningham Bowler
6 * Last changed in libpng 1.6.24 [August 4, 2016]
8 * This code is released under the libpng license.
9 * For conditions of distribution and use, see the disclaimer
10 * and license in png.h
12 * Test for the PNG 'simplified' APIs.
14 #define _ISOC90_SOURCE 1
15 #define MALLOC_CHECK_ 2/*glibc facility: turn on debugging*/
25 #if defined(HAVE_CONFIG_H) && !defined(PNG_NO_CONFIG_H)
29 /* Define the following to use this test against your installed libpng, rather
30 * than the one being built here:
32 #ifdef PNG_FREESTANDING_TESTS
35 # include "../../png.h"
38 /* 1.6.1 added support for the configure test harness, which uses 77 to indicate
39 * a skipped test, in earlier versions we need to succeed on a skipped test, so:
41 #if PNG_LIBPNG_VER >= 10601 && defined(HAVE_CONFIG_H)
47 #ifdef PNG_SIMPLIFIED_READ_SUPPORTED /* Else nothing can be done */
48 #include "../tools/sRGB.h"
52 * These defines switch on alternate algorithms for format conversions to match
53 * the current libpng implementation; they are set to allow pngstest to pass
54 * even though libpng is producing answers that are not as correct as they
57 #define ALLOW_UNUSED_GPC 0
58 /* If true include unused static GPC functions and declare an external array
59 * of them to hide the fact that they are unused. This is for development
60 * use while testing the correct function to use to take into account libpng
61 * misbehavior, such as using a simple power law to correct sRGB to linear.
64 /* The following is to support direct compilation of this file as C++ */
66 # define voidcast(type, value) static_cast<type>(value)
67 # define aligncastconst(type, value) \
68 static_cast<type>(static_cast<const void*>(value))
70 # define voidcast(type, value) (value)
71 # define aligncastconst(type, value) ((const void*)(value))
72 #endif /* __cplusplus */
74 /* During parallel runs of pngstest each temporary file needs a unique name,
75 * this is used to permit uniqueness using a command line argument which can be
76 * up to 22 characters long.
78 static char tmpf
[23] = "TMP";
80 /* Generate random bytes. This uses a boring repeatable algorithm and it
81 * is implemented here so that it gives the same set of numbers on every
82 * architecture. It's a linear congruential generator (Knuth or Sedgewick
83 * "Algorithms") but it comes from the 'feedback taps' table in Horowitz and
84 * Hill, "The Art of Electronics".
87 make_random_bytes(png_uint_32
* seed
, void* pv
, size_t size
)
89 png_uint_32 u0
= seed
[0], u1
= seed
[1];
90 png_bytep bytes
= voidcast(png_bytep
, pv
);
92 /* There are thirty three bits, the next bit in the sequence is bit-33 XOR
93 * bit-20. The top 1 bit is in u1, the bottom 32 are in u0.
96 for (i
=0; i
<size
; ++i
)
98 /* First generate 8 new bits then shift them in at the end. */
99 png_uint_32 u
= ((u0
>> (20-8)) ^ ((u1
<< 7) | (u0
>> (32-7)))) & 0xff;
104 *bytes
++ = (png_byte
)u
;
111 static png_uint_32 color_seed
[2];
116 color_seed
[0] = 0x12345678U
;
117 color_seed
[1] = 0x9abcdefU
;
121 random_color(png_colorp color
)
123 make_random_bytes(color_seed
, color
, sizeof *color
);
126 /* Math support - neither Cygwin nor Visual Studio have C99 support and we need
127 * a predictable rounding function, so make one here:
130 closestinteger(double x
)
132 return floor(x
+ .5);
135 /* Cast support: remove GCC whines. */
139 d
= closestinteger(d
);
146 d
= closestinteger(d
);
147 return (png_uint_16
)d
;
150 /* sRGB support: use exact calculations rounded to the nearest int, see the
151 * fesetround() call in main(). sRGB_to_d optimizes the 8 to 16-bit conversion.
153 static double sRGB_to_d
[256];
154 static double g22_to_d
[256];
162 for (i
=1; i
<255; ++i
)
163 sRGB_to_d
[i
] = linear_from_sRGB(i
/255.);
167 for (i
=1; i
<255; ++i
)
168 g22_to_d
[i
] = pow(i
/255., 1/.45455);
173 sRGB(double linear
/*range 0.0 .. 1.0*/)
175 return u8d(255 * sRGB_from_linear(linear
));
179 isRGB(int fixed_linear
)
181 return sRGB(fixed_linear
/ 65535.);
186 unpremultiply(int component
, int alpha
)
188 if (alpha
<= component
)
189 return 255; /* Arbitrary, but consistent with the libpng code */
191 else if (alpha
>= 65535)
192 return isRGB(component
);
195 return sRGB((double)component
/ alpha
);
200 ilinear(int fixed_srgb
)
202 return u16d(65535 * sRGB_to_d
[fixed_srgb
]);
206 ilineara(int fixed_srgb
, int alpha
)
208 return u16d((257 * alpha
) * sRGB_to_d
[fixed_srgb
]);
212 ilinear_g22(int fixed_srgb
)
214 return u16d(65535 * g22_to_d
[fixed_srgb
]);
219 ilineara_g22(int fixed_srgb
, int alpha
)
221 return u16d((257 * alpha
) * g22_to_d
[fixed_srgb
]);
226 YfromRGBint(int ir
, int ig
, int ib
)
231 return YfromRGB(r
, g
, b
);
235 /* The error that results from using a 2.2 power law in place of the correct
236 * sRGB transform, given an 8-bit value which might be either sRGB or power-law.
239 power_law_error8(int value
)
241 if (value
> 0 && value
< 255)
243 double vd
= value
/ 255.;
245 pow(sRGB_to_d
[value
], 1/2.2) - sRGB_from_linear(pow(vd
, 2.2)));
247 /* Always allow an extra 1 here for rounding errors */
248 e
= 1+floor(255 * e
);
255 static int error_in_sRGB_roundtrip
= 56; /* by experiment */
257 power_law_error16(int value
)
259 if (value
> 0 && value
< 65535)
261 /* Round trip the value through an 8-bit representation but using
262 * non-matching to/from conversions.
264 double vd
= value
/ 65535.;
266 pow(sRGB_from_linear(vd
), 2.2) - linear_from_sRGB(pow(vd
, 1/2.2)));
268 /* Always allow an extra 1 here for rounding errors */
269 e
= error_in_sRGB_roundtrip
+floor(65535 * e
);
277 compare_8bit(int v1
, int v2
, int error_limit
, int multiple_algorithms
)
282 if (e
<= error_limit
)
285 if (!multiple_algorithms
)
288 ev1
= power_law_error8(v1
);
292 ev2
= power_law_error8(v2
);
300 compare_16bit(int v1
, int v2
, int error_limit
, int multiple_algorithms
)
305 if (e
<= error_limit
)
308 /* "multiple_algorithms" in this case means that a color-map has been
309 * involved somewhere, so we can deduce that the values were forced to 8-bit
310 * (like the via_linear case for 8-bit.)
312 if (!multiple_algorithms
)
315 ev1
= power_law_error16(v1
);
319 ev2
= power_law_error16(v2
);
327 #define USE_FILE 1 /* else memory */
328 #define USE_STDIO 2 /* else use file name */
329 #define STRICT 4 /* fail on warnings too */
331 #define KEEP_TMPFILES 16 /* else delete temporary files */
332 #define KEEP_GOING 32
333 #define ACCUMULATE 64
334 #define FAST_WRITE 128
335 #define sRGB_16BIT 256
336 #define NO_RESEED 512 /* do not reseed on each new file */
337 #define GBG_ERROR 1024 /* do not ignore the gamma+background_rgb_to_gray
341 print_opts(png_uint_32 opts
)
345 if (opts
& USE_STDIO
)
347 if (!(opts
& STRICT
))
348 printf(" --nostrict");
350 printf(" --verbose");
351 if (opts
& KEEP_TMPFILES
)
352 printf(" --preserve");
353 if (opts
& KEEP_GOING
)
354 printf(" --keep-going");
355 if (opts
& ACCUMULATE
)
356 printf(" --accumulate");
357 if (!(opts
& FAST_WRITE
)) /* --fast is currently the default */
359 if (opts
& sRGB_16BIT
)
360 printf(" --sRGB-16bit");
361 if (opts
& NO_RESEED
)
362 printf(" --noreseed");
363 #if PNG_LIBPNG_VER < 10700 /* else on by default */
364 if (opts
& GBG_ERROR
)
365 printf(" --fault-gbg-warning");
369 #define FORMAT_NO_CHANGE 0x80000000 /* additional flag */
371 /* A name table for all the formats - defines the format of the '+' arguments to
374 #define FORMAT_COUNT 64
375 #define FORMAT_MASK 0x3f
376 static PNG_CONST
char * PNG_CONST format_names
[FORMAT_COUNT
] =
387 "color-mapped-sRGB-gray",
388 "color-mapped-sRGB-gray+alpha",
389 "color-mapped-sRGB-rgb",
390 "color-mapped-sRGB-rgb+alpha",
391 "color-mapped-linear-gray",
392 "color-mapped-linear-gray+alpha",
393 "color-mapped-linear-rgb",
394 "color-mapped-linear-rgb+alpha",
405 "color-mapped-sRGB-gray",
406 "color-mapped-sRGB-gray+alpha",
407 "color-mapped-sRGB-bgr",
408 "color-mapped-sRGB-bgr+alpha",
409 "color-mapped-linear-gray",
410 "color-mapped-linear-gray+alpha",
411 "color-mapped-linear-bgr",
412 "color-mapped-linear-bgr+alpha",
423 "color-mapped-sRGB-gray",
424 "color-mapped-alpha+sRGB-gray",
425 "color-mapped-sRGB-rgb",
426 "color-mapped-alpha+sRGB-rgb",
427 "color-mapped-linear-gray",
428 "color-mapped-alpha+linear-gray",
429 "color-mapped-linear-rgb",
430 "color-mapped-alpha+linear-rgb",
441 "color-mapped-sRGB-gray",
442 "color-mapped-alpha+sRGB-gray",
443 "color-mapped-sRGB-bgr",
444 "color-mapped-alpha+sRGB-bgr",
445 "color-mapped-linear-gray",
446 "color-mapped-alpha+linear-gray",
447 "color-mapped-linear-bgr",
448 "color-mapped-alpha+linear-bgr",
451 /* Decode an argument to a format number. */
453 formatof(const char *arg
)
456 unsigned long format
= strtoul(arg
, &ep
, 0);
458 if (ep
> arg
&& *ep
== 0 && format
< FORMAT_COUNT
)
459 return (png_uint_32
)format
;
461 else for (format
=0; format
< FORMAT_COUNT
; ++format
)
463 if (strcmp(format_names
[format
], arg
) == 0)
464 return (png_uint_32
)format
;
467 fprintf(stderr
, "pngstest: format name '%s' invalid\n", arg
);
471 /* Bitset/test functions for formats */
472 #define FORMAT_SET_COUNT (FORMAT_COUNT / 32)
475 png_uint_32 bits
[FORMAT_SET_COUNT
];
479 static void format_init(format_list
*pf
)
482 for (i
=0; i
<FORMAT_SET_COUNT
; ++i
)
483 pf
->bits
[i
] = 0; /* All off */
486 #if 0 /* currently unused */
487 static void format_clear(format_list
*pf
)
490 for (i
=0; i
<FORMAT_SET_COUNT
; ++i
)
495 static int format_is_initial(format_list
*pf
)
498 for (i
=0; i
<FORMAT_SET_COUNT
; ++i
)
499 if (pf
->bits
[i
] != 0)
505 static int format_set(format_list
*pf
, png_uint_32 format
)
507 if (format
< FORMAT_COUNT
)
508 return pf
->bits
[format
>> 5] |= ((png_uint_32
)1) << (format
& 31);
513 #if 0 /* currently unused */
514 static int format_unset(format_list
*pf
, png_uint_32 format
)
516 if (format
< FORMAT_COUNT
)
517 return pf
->bits
[format
>> 5] &= ~((png_uint_32
)1) << (format
& 31);
523 static int format_isset(format_list
*pf
, png_uint_32 format
)
525 return format
< FORMAT_COUNT
&&
526 (pf
->bits
[format
>> 5] & (((png_uint_32
)1) << (format
& 31))) != 0;
529 static void format_default(format_list
*pf
, int redundant
)
535 /* set everything, including flags that are pointless */
536 for (i
=0; i
<FORMAT_SET_COUNT
; ++i
)
537 pf
->bits
[i
] = ~(png_uint_32
)0;
544 for (f
=0; f
<FORMAT_COUNT
; ++f
)
546 /* Eliminate redundant and unsupported settings. */
547 # ifdef PNG_FORMAT_BGR_SUPPORTED
548 /* BGR is meaningless if no color: */
549 if ((f
& PNG_FORMAT_FLAG_COLOR
) == 0 &&
550 (f
& PNG_FORMAT_FLAG_BGR
) != 0)
552 if ((f
& 0x10U
/*HACK: fixed value*/) != 0)
556 /* AFIRST is meaningless if no alpha: */
557 # ifdef PNG_FORMAT_AFIRST_SUPPORTED
558 if ((f
& PNG_FORMAT_FLAG_ALPHA
) == 0 &&
559 (f
& PNG_FORMAT_FLAG_AFIRST
) != 0)
561 if ((f
& 0x20U
/*HACK: fixed value*/) != 0)
570 /* THE Image STRUCTURE */
571 /* The super-class of a png_image, contains the decoded image plus the input
572 * data necessary to re-read the file with a different format.
578 const char *file_name
;
581 png_voidp input_memory
;
582 png_size_t input_memory_size
;
586 png_size_t allocsize
;
587 char tmpfile_name
[32];
588 png_uint_16 colormap
[256*4];
592 /* Initializer: also sets the permitted error limit for 16-bit operations. */
594 newimage(Image
*image
)
596 memset(image
, 0, sizeof *image
);
599 /* Reset the image to be read again - only needs to rewind the FILE* at present.
602 resetimage(Image
*image
)
604 if (image
->input_file
!= NULL
)
605 rewind(image
->input_file
);
608 /* Free the image buffer; the buffer is re-used on a re-read, this is just for
612 freebuffer(Image
*image
)
614 if (image
->buffer
) free(image
->buffer
);
615 image
->buffer
= NULL
;
617 image
->allocsize
= 0;
620 /* Delete function; cleans out all the allocated data and the temporary file in
624 freeimage(Image
*image
)
627 png_image_free(&image
->image
);
629 if (image
->input_file
!= NULL
)
631 fclose(image
->input_file
);
632 image
->input_file
= NULL
;
635 if (image
->input_memory
!= NULL
)
637 free(image
->input_memory
);
638 image
->input_memory
= NULL
;
639 image
->input_memory_size
= 0;
642 if (image
->tmpfile_name
[0] != 0 && (image
->opts
& KEEP_TMPFILES
) == 0)
644 (void)remove(image
->tmpfile_name
);
645 image
->tmpfile_name
[0] = 0;
649 /* This is actually a re-initializer; allows an image structure to be re-used by
650 * freeing everything that relates to an old image.
652 static void initimage(Image
*image
, png_uint_32 opts
, const char *file_name
,
656 memset(&image
->image
, 0, sizeof image
->image
);
658 image
->file_name
= file_name
;
659 image
->stride_extra
= stride_extra
;
662 /* Make sure the image buffer is big enough; allows re-use of the buffer if the
665 #define BUFFER_INIT8 73
667 allocbuffer(Image
*image
)
669 png_size_t size
= PNG_IMAGE_BUFFER_SIZE(image
->image
, image
->stride
);
671 if (size
+32 > image
->bufsize
)
674 image
->buffer
= voidcast(png_bytep
, malloc(size
+32));
675 if (image
->buffer
== NULL
)
679 "simpletest: out of memory allocating %lu(+32) byte buffer\n",
680 (unsigned long)size
);
683 image
->bufsize
= size
+32;
686 memset(image
->buffer
, 95, image
->bufsize
);
687 memset(image
->buffer
+16, BUFFER_INIT8
, size
);
688 image
->allocsize
= size
;
691 /* Make sure 16 bytes match the given byte. */
693 check16(png_const_bytep bp
, int b
)
698 if (*bp
!= b
) return 1;
704 /* Check for overwrite in the image buffer. */
706 checkbuffer(Image
*image
, const char *arg
)
708 if (check16(image
->buffer
, 95))
711 fprintf(stderr
, "%s: overwrite at start of image buffer\n", arg
);
715 if (check16(image
->buffer
+16+image
->allocsize
, 95))
718 fprintf(stderr
, "%s: overwrite at end of image buffer\n", arg
);
724 /* Log a terminal error, also frees the libpng part of the image if necessary.
727 logerror(Image
*image
, const char *a1
, const char *a2
, const char *a3
)
730 if (image
->image
.warning_or_error
)
731 fprintf(stderr
, "%s%s%s: %s\n", a1
, a2
, a3
, image
->image
.message
);
734 fprintf(stderr
, "%s%s%s\n", a1
, a2
, a3
);
736 if (image
->image
.opaque
!= NULL
)
738 fprintf(stderr
, "%s: image opaque pointer non-NULL on error\n",
740 png_image_free(&image
->image
);
746 /* Log an error and close a file (just a utility to do both things in one
750 logclose(Image
*image
, FILE *f
, const char *name
, const char *operation
)
755 return logerror(image
, name
, operation
, strerror(e
));
758 /* Make sure the png_image has been freed - validates that libpng is doing what
759 * the spec says and freeing the image.
762 checkopaque(Image
*image
)
764 if (image
->image
.opaque
!= NULL
)
766 png_image_free(&image
->image
);
767 return logerror(image
, image
->file_name
, ": opaque not NULL", "");
770 /* Separate out the gamma+background_rgb_to_gray warning because it may
771 * produce opaque component errors:
773 else if (image
->image
.warning_or_error
!= 0 &&
774 (strcmp(image
->image
.message
,
775 "libpng does not support gamma+background+rgb_to_gray") == 0 ?
776 (image
->opts
& GBG_ERROR
) != 0 : (image
->opts
& STRICT
) != 0))
777 return logerror(image
, image
->file_name
, (image
->opts
& GBG_ERROR
) != 0 ?
778 " --fault-gbg-warning" : " --strict", "");
784 /* IMAGE COMPARISON/CHECKING */
785 /* Compare the pixels of two images, which should be the same but aren't. The
786 * images must have been checked for a size match.
790 /* The components, for grayscale images the gray value is in 'g' and if alpha
791 * is not present 'a' is set to 255 or 65535 according to format.
798 /* The background as the original sRGB 8-bit value converted to the final
799 * integer format and as a double precision linear value in the range 0..1
800 * for with partially transparent pixels.
803 double dr
, dg
, db
; /* linear r,g,b scaled to 0..1 */
806 /* Basic image formats; control the data but not the layout thereof. */
807 #define BASE_FORMATS\
808 (PNG_FORMAT_FLAG_ALPHA|PNG_FORMAT_FLAG_COLOR|PNG_FORMAT_FLAG_LINEAR)
810 /* Read a Pixel from a buffer. The code below stores the correct routine for
811 * the format in a function pointer, these are the routines:
814 gp_g8(Pixel
*p
, png_const_voidp pb
)
816 png_const_bytep pp
= voidcast(png_const_bytep
, pb
);
818 p
->r
= p
->g
= p
->b
= pp
[0];
823 gp_ga8(Pixel
*p
, png_const_voidp pb
)
825 png_const_bytep pp
= voidcast(png_const_bytep
, pb
);
827 p
->r
= p
->g
= p
->b
= pp
[0];
831 #ifdef PNG_FORMAT_AFIRST_SUPPORTED
833 gp_ag8(Pixel
*p
, png_const_voidp pb
)
835 png_const_bytep pp
= voidcast(png_const_bytep
, pb
);
837 p
->r
= p
->g
= p
->b
= pp
[1];
843 gp_rgb8(Pixel
*p
, png_const_voidp pb
)
845 png_const_bytep pp
= voidcast(png_const_bytep
, pb
);
853 #ifdef PNG_FORMAT_BGR_SUPPORTED
855 gp_bgr8(Pixel
*p
, png_const_voidp pb
)
857 png_const_bytep pp
= voidcast(png_const_bytep
, pb
);
867 gp_rgba8(Pixel
*p
, png_const_voidp pb
)
869 png_const_bytep pp
= voidcast(png_const_bytep
, pb
);
877 #ifdef PNG_FORMAT_BGR_SUPPORTED
879 gp_bgra8(Pixel
*p
, png_const_voidp pb
)
881 png_const_bytep pp
= voidcast(png_const_bytep
, pb
);
890 #ifdef PNG_FORMAT_AFIRST_SUPPORTED
892 gp_argb8(Pixel
*p
, png_const_voidp pb
)
894 png_const_bytep pp
= voidcast(png_const_bytep
, pb
);
903 #if defined(PNG_FORMAT_AFIRST_SUPPORTED) && defined(PNG_FORMAT_BGR_SUPPORTED)
905 gp_abgr8(Pixel
*p
, png_const_voidp pb
)
907 png_const_bytep pp
= voidcast(png_const_bytep
, pb
);
917 gp_g16(Pixel
*p
, png_const_voidp pb
)
919 png_const_uint_16p pp
= voidcast(png_const_uint_16p
, pb
);
921 p
->r
= p
->g
= p
->b
= pp
[0];
926 gp_ga16(Pixel
*p
, png_const_voidp pb
)
928 png_const_uint_16p pp
= voidcast(png_const_uint_16p
, pb
);
930 p
->r
= p
->g
= p
->b
= pp
[0];
934 #ifdef PNG_FORMAT_AFIRST_SUPPORTED
936 gp_ag16(Pixel
*p
, png_const_voidp pb
)
938 png_const_uint_16p pp
= voidcast(png_const_uint_16p
, pb
);
940 p
->r
= p
->g
= p
->b
= pp
[1];
946 gp_rgb16(Pixel
*p
, png_const_voidp pb
)
948 png_const_uint_16p pp
= voidcast(png_const_uint_16p
, pb
);
956 #ifdef PNG_FORMAT_BGR_SUPPORTED
958 gp_bgr16(Pixel
*p
, png_const_voidp pb
)
960 png_const_uint_16p pp
= voidcast(png_const_uint_16p
, pb
);
970 gp_rgba16(Pixel
*p
, png_const_voidp pb
)
972 png_const_uint_16p pp
= voidcast(png_const_uint_16p
, pb
);
980 #ifdef PNG_FORMAT_BGR_SUPPORTED
982 gp_bgra16(Pixel
*p
, png_const_voidp pb
)
984 png_const_uint_16p pp
= voidcast(png_const_uint_16p
, pb
);
993 #ifdef PNG_FORMAT_AFIRST_SUPPORTED
995 gp_argb16(Pixel
*p
, png_const_voidp pb
)
997 png_const_uint_16p pp
= voidcast(png_const_uint_16p
, pb
);
1006 #if defined(PNG_FORMAT_AFIRST_SUPPORTED) && defined(PNG_FORMAT_BGR_SUPPORTED)
1008 gp_abgr16(Pixel
*p
, png_const_voidp pb
)
1010 png_const_uint_16p pp
= voidcast(png_const_uint_16p
, pb
);
1019 /* Given a format, return the correct one of the above functions. */
1021 get_pixel(png_uint_32 format
))(Pixel
*p
, png_const_voidp pb
)
1023 /* The color-map flag is irrelevant here - the caller of the function
1024 * returned must either pass the buffer or, for a color-mapped image, the
1025 * correct entry in the color-map.
1027 if (format
& PNG_FORMAT_FLAG_LINEAR
)
1029 if (format
& PNG_FORMAT_FLAG_COLOR
)
1031 # ifdef PNG_FORMAT_BGR_SUPPORTED
1032 if (format
& PNG_FORMAT_FLAG_BGR
)
1034 if (format
& PNG_FORMAT_FLAG_ALPHA
)
1036 # ifdef PNG_FORMAT_AFIRST_SUPPORTED
1037 if (format
& PNG_FORMAT_FLAG_AFIRST
)
1052 if (format
& PNG_FORMAT_FLAG_ALPHA
)
1054 # ifdef PNG_FORMAT_AFIRST_SUPPORTED
1055 if (format
& PNG_FORMAT_FLAG_AFIRST
)
1070 if (format
& PNG_FORMAT_FLAG_ALPHA
)
1072 # ifdef PNG_FORMAT_AFIRST_SUPPORTED
1073 if (format
& PNG_FORMAT_FLAG_AFIRST
)
1088 if (format
& PNG_FORMAT_FLAG_COLOR
)
1090 # ifdef PNG_FORMAT_BGR_SUPPORTED
1091 if (format
& PNG_FORMAT_FLAG_BGR
)
1093 if (format
& PNG_FORMAT_FLAG_ALPHA
)
1095 # ifdef PNG_FORMAT_AFIRST_SUPPORTED
1096 if (format
& PNG_FORMAT_FLAG_AFIRST
)
1111 if (format
& PNG_FORMAT_FLAG_ALPHA
)
1113 # ifdef PNG_FORMAT_AFIRST_SUPPORTED
1114 if (format
& PNG_FORMAT_FLAG_AFIRST
)
1129 if (format
& PNG_FORMAT_FLAG_ALPHA
)
1131 # ifdef PNG_FORMAT_AFIRST_SUPPORTED
1132 if (format
& PNG_FORMAT_FLAG_AFIRST
)
1146 /* Convertion between pixel formats. The code above effectively eliminates the
1147 * component ordering changes leaving three basic changes:
1149 * 1) Remove an alpha channel by pre-multiplication or compositing on a
1150 * background color. (Adding an alpha channel is a no-op.)
1152 * 2) Remove color by mapping to grayscale. (Grayscale to color is a no-op.)
1154 * 3) Convert between 8-bit and 16-bit components. (Both directtions are
1157 * This gives the following base format conversion matrix:
1159 * OUT: ----- 8-bit ----- ----- 16-bit -----
1160 * IN G GA RGB RGBA G GA RGB RGBA
1161 * 8 G . . . . lin lin lin lin
1162 * 8 GA bckg . bckc . pre' pre pre' pre
1163 * 8 RGB g8 g8 . . glin glin lin lin
1164 * 8 RGBA g8b g8 bckc . gpr' gpre pre' pre
1165 * 16 G sRGB sRGB sRGB sRGB . . . .
1166 * 16 GA b16g unpg b16c unpc A . A .
1167 * 16 RGB sG sG sRGB sRGB g16 g16 . .
1168 * 16 RGBA gb16 sGp cb16 sCp g16 g16' A .
1171 * bckg: composite on gray background
1172 * bckc: composite on color background
1173 * g8: convert sRGB components to sRGB grayscale
1174 * g8b: convert sRGB components to grayscale and composite on gray background
1177 * lin: make sRGB components linear, alpha := 65535
1178 * pre: make sRGB components linear and premultiply by alpha (scale alpha)
1179 * pre': as 'pre' but alpha := 65535
1180 * glin: make sRGB components linear, convert to grayscale, alpha := 65535
1181 * gpre: make sRGB components grayscale and linear and premultiply by alpha
1182 * gpr': as 'gpre' but alpha := 65535
1185 * sRGB: convert linear components to sRGB, alpha := 255
1186 * unpg: unpremultiply gray component and convert to sRGB (scale alpha)
1187 * unpc: unpremultiply color components and convert to sRGB (scale alpha)
1188 * b16g: composite linear onto gray background and convert the result to sRGB
1189 * b16c: composite linear onto color background and convert the result to sRGB
1190 * sG: convert linear RGB to sRGB grayscale
1191 * sGp: unpremultiply RGB then convert to sRGB grayscale
1192 * sCp: unpremultiply RGB then convert to sRGB
1193 * gb16: composite linear onto background and convert to sRGB grayscale
1194 * (order doesn't matter, the composite and grayscale operations permute)
1195 * cb16: composite linear onto background and convert to sRGB
1198 * A: set alpha to 65535
1199 * g16: convert linear RGB to linear grayscale (alpha := 65535)
1200 * g16': as 'g16' but alpha is unchanged
1204 gpc_noop(Pixel
*out
, const Pixel
*in
, const Background
*back
)
1213 #if ALLOW_UNUSED_GPC
1215 gpc_nop8(Pixel
*out
, const Pixel
*in
, const Background
*back
)
1219 out
->r
= out
->g
= out
->b
= 255;
1232 #if ALLOW_UNUSED_GPC
1234 gpc_nop6(Pixel
*out
, const Pixel
*in
, const Background
*back
)
1238 out
->r
= out
->g
= out
->b
= 65535;
1251 /* 8-bit to 8-bit conversions */
1252 /* bckg: composite on gray background */
1254 gpc_bckg(Pixel
*out
, const Pixel
*in
, const Background
*back
)
1257 out
->r
= out
->g
= out
->b
= back
->ig
;
1259 else if (in
->a
>= 255)
1260 out
->r
= out
->g
= out
->b
= in
->g
;
1264 double a
= in
->a
/ 255.;
1266 out
->r
= out
->g
= out
->b
= sRGB(sRGB_to_d
[in
->g
] * a
+ back
->dg
* (1-a
));
1272 /* bckc: composite on color background */
1274 gpc_bckc(Pixel
*out
, const Pixel
*in
, const Background
*back
)
1283 else if (in
->a
>= 255)
1292 double a
= in
->a
/ 255.;
1294 out
->r
= sRGB(sRGB_to_d
[in
->r
] * a
+ back
->dr
* (1-a
));
1295 out
->g
= sRGB(sRGB_to_d
[in
->g
] * a
+ back
->dg
* (1-a
));
1296 out
->b
= sRGB(sRGB_to_d
[in
->b
] * a
+ back
->db
* (1-a
));
1302 /* g8: convert sRGB components to sRGB grayscale */
1304 gpc_g8(Pixel
*out
, const Pixel
*in
, const Background
*back
)
1308 if (in
->r
== in
->g
&& in
->g
== in
->b
)
1309 out
->r
= out
->g
= out
->b
= in
->g
;
1312 out
->r
= out
->g
= out
->b
=
1313 sRGB(YfromRGB(sRGB_to_d
[in
->r
], sRGB_to_d
[in
->g
], sRGB_to_d
[in
->b
]));
1318 /* g8b: convert sRGB components to grayscale and composite on gray background */
1320 gpc_g8b(Pixel
*out
, const Pixel
*in
, const Background
*back
)
1323 out
->r
= out
->g
= out
->b
= back
->ig
;
1325 else if (in
->a
>= 255)
1327 if (in
->r
== in
->g
&& in
->g
== in
->b
)
1328 out
->r
= out
->g
= out
->b
= in
->g
;
1331 out
->r
= out
->g
= out
->b
= sRGB(YfromRGB(
1332 sRGB_to_d
[in
->r
], sRGB_to_d
[in
->g
], sRGB_to_d
[in
->b
]));
1337 double a
= in
->a
/255.;
1339 out
->r
= out
->g
= out
->b
= sRGB(a
* YfromRGB(sRGB_to_d
[in
->r
],
1340 sRGB_to_d
[in
->g
], sRGB_to_d
[in
->b
]) + back
->dg
* (1-a
));
1346 /* 8-bit to 16-bit conversions */
1347 /* lin: make sRGB components linear, alpha := 65535 */
1349 gpc_lin(Pixel
*out
, const Pixel
*in
, const Background
*back
)
1353 out
->r
= ilinear(in
->r
);
1363 out
->b
= ilinear(in
->b
);
1368 out
->g
= ilinear(in
->g
);
1373 else if (in
->b
== in
->g
)
1377 out
->b
= ilinear(in
->b
);
1383 /* pre: make sRGB components linear and premultiply by alpha (scale alpha) */
1385 gpc_pre(Pixel
*out
, const Pixel
*in
, const Background
*back
)
1389 out
->r
= ilineara(in
->r
, in
->a
);
1399 out
->b
= ilineara(in
->b
, in
->a
);
1404 out
->g
= ilineara(in
->g
, in
->a
);
1409 else if (in
->b
== in
->g
)
1413 out
->b
= ilineara(in
->b
, in
->a
);
1416 out
->a
= in
->a
* 257;
1419 /* pre': as 'pre' but alpha := 65535 */
1421 gpc_preq(Pixel
*out
, const Pixel
*in
, const Background
*back
)
1425 out
->r
= ilineara(in
->r
, in
->a
);
1435 out
->b
= ilineara(in
->b
, in
->a
);
1440 out
->g
= ilineara(in
->g
, in
->a
);
1445 else if (in
->b
== in
->g
)
1449 out
->b
= ilineara(in
->b
, in
->a
);
1455 /* glin: make sRGB components linear, convert to grayscale, alpha := 65535 */
1457 gpc_glin(Pixel
*out
, const Pixel
*in
, const Background
*back
)
1461 if (in
->r
== in
->g
&& in
->g
== in
->b
)
1462 out
->r
= out
->g
= out
->b
= ilinear(in
->g
);
1465 out
->r
= out
->g
= out
->b
= u16d(65535 *
1466 YfromRGB(sRGB_to_d
[in
->r
], sRGB_to_d
[in
->g
], sRGB_to_d
[in
->b
]));
1471 /* gpre: make sRGB components grayscale and linear and premultiply by alpha */
1473 gpc_gpre(Pixel
*out
, const Pixel
*in
, const Background
*back
)
1477 if (in
->r
== in
->g
&& in
->g
== in
->b
)
1478 out
->r
= out
->g
= out
->b
= ilineara(in
->g
, in
->a
);
1481 out
->r
= out
->g
= out
->b
= u16d(in
->a
* 257 *
1482 YfromRGB(sRGB_to_d
[in
->r
], sRGB_to_d
[in
->g
], sRGB_to_d
[in
->b
]));
1484 out
->a
= 257 * in
->a
;
1487 /* gpr': as 'gpre' but alpha := 65535 */
1489 gpc_gprq(Pixel
*out
, const Pixel
*in
, const Background
*back
)
1493 if (in
->r
== in
->g
&& in
->g
== in
->b
)
1494 out
->r
= out
->g
= out
->b
= ilineara(in
->g
, in
->a
);
1497 out
->r
= out
->g
= out
->b
= u16d(in
->a
* 257 *
1498 YfromRGB(sRGB_to_d
[in
->r
], sRGB_to_d
[in
->g
], sRGB_to_d
[in
->b
]));
1503 /* 8-bit to 16-bit conversions for gAMA 45455 encoded values */
1504 /* Lin: make gAMA 45455 components linear, alpha := 65535 */
1506 gpc_Lin(Pixel
*out
, const Pixel
*in
, const Background
*back
)
1510 out
->r
= ilinear_g22(in
->r
);
1520 out
->b
= ilinear_g22(in
->b
);
1525 out
->g
= ilinear_g22(in
->g
);
1530 else if (in
->b
== in
->g
)
1534 out
->b
= ilinear_g22(in
->b
);
1540 #if ALLOW_UNUSED_GPC
1541 /* Pre: make gAMA 45455 components linear and premultiply by alpha (scale alpha)
1544 gpc_Pre(Pixel
*out
, const Pixel
*in
, const Background
*back
)
1548 out
->r
= ilineara_g22(in
->r
, in
->a
);
1558 out
->b
= ilineara_g22(in
->b
, in
->a
);
1563 out
->g
= ilineara_g22(in
->g
, in
->a
);
1568 else if (in
->b
== in
->g
)
1572 out
->b
= ilineara_g22(in
->b
, in
->a
);
1575 out
->a
= in
->a
* 257;
1579 #if ALLOW_UNUSED_GPC
1580 /* Pre': as 'Pre' but alpha := 65535 */
1582 gpc_Preq(Pixel
*out
, const Pixel
*in
, const Background
*back
)
1586 out
->r
= ilineara_g22(in
->r
, in
->a
);
1596 out
->b
= ilineara_g22(in
->b
, in
->a
);
1601 out
->g
= ilineara_g22(in
->g
, in
->a
);
1606 else if (in
->b
== in
->g
)
1610 out
->b
= ilineara_g22(in
->b
, in
->a
);
1617 #if ALLOW_UNUSED_GPC
1618 /* Glin: make gAMA 45455 components linear, convert to grayscale, alpha := 65535
1621 gpc_Glin(Pixel
*out
, const Pixel
*in
, const Background
*back
)
1625 if (in
->r
== in
->g
&& in
->g
== in
->b
)
1626 out
->r
= out
->g
= out
->b
= ilinear_g22(in
->g
);
1629 out
->r
= out
->g
= out
->b
= u16d(65535 *
1630 YfromRGB(g22_to_d
[in
->r
], g22_to_d
[in
->g
], g22_to_d
[in
->b
]));
1636 #if ALLOW_UNUSED_GPC
1637 /* Gpre: make gAMA 45455 components grayscale and linear and premultiply by
1641 gpc_Gpre(Pixel
*out
, const Pixel
*in
, const Background
*back
)
1645 if (in
->r
== in
->g
&& in
->g
== in
->b
)
1646 out
->r
= out
->g
= out
->b
= ilineara_g22(in
->g
, in
->a
);
1649 out
->r
= out
->g
= out
->b
= u16d(in
->a
* 257 *
1650 YfromRGB(g22_to_d
[in
->r
], g22_to_d
[in
->g
], g22_to_d
[in
->b
]));
1652 out
->a
= 257 * in
->a
;
1656 #if ALLOW_UNUSED_GPC
1657 /* Gpr': as 'Gpre' but alpha := 65535 */
1659 gpc_Gprq(Pixel
*out
, const Pixel
*in
, const Background
*back
)
1663 if (in
->r
== in
->g
&& in
->g
== in
->b
)
1664 out
->r
= out
->g
= out
->b
= ilineara_g22(in
->g
, in
->a
);
1667 out
->r
= out
->g
= out
->b
= u16d(in
->a
* 257 *
1668 YfromRGB(g22_to_d
[in
->r
], g22_to_d
[in
->g
], g22_to_d
[in
->b
]));
1674 /* 16-bit to 8-bit conversions */
1675 /* sRGB: convert linear components to sRGB, alpha := 255 */
1677 gpc_sRGB(Pixel
*out
, const Pixel
*in
, const Background
*back
)
1681 out
->r
= isRGB(in
->r
);
1691 out
->b
= isRGB(in
->b
);
1696 out
->g
= isRGB(in
->g
);
1701 else if (in
->b
== in
->g
)
1705 out
->b
= isRGB(in
->b
);
1711 /* unpg: unpremultiply gray component and convert to sRGB (scale alpha) */
1713 gpc_unpg(Pixel
*out
, const Pixel
*in
, const Background
*back
)
1719 out
->r
= out
->g
= out
->b
= 255;
1725 out
->r
= out
->g
= out
->b
= sRGB((double)in
->g
/ in
->a
);
1726 out
->a
= u8d(in
->a
/ 257.);
1730 /* unpc: unpremultiply color components and convert to sRGB (scale alpha) */
1732 gpc_unpc(Pixel
*out
, const Pixel
*in
, const Background
*back
)
1738 out
->r
= out
->g
= out
->b
= 255;
1744 out
->r
= sRGB((double)in
->r
/ in
->a
);
1745 out
->g
= sRGB((double)in
->g
/ in
->a
);
1746 out
->b
= sRGB((double)in
->b
/ in
->a
);
1747 out
->a
= u8d(in
->a
/ 257.);
1751 /* b16g: composite linear onto gray background and convert the result to sRGB */
1753 gpc_b16g(Pixel
*out
, const Pixel
*in
, const Background
*back
)
1756 out
->r
= out
->g
= out
->b
= back
->ig
;
1760 double a
= in
->a
/65535.;
1764 out
->r
= out
->g
= out
->b
= sRGB(in
->g
* a
+ back
->dg
* a1
);
1770 /* b16c: composite linear onto color background and convert the result to sRGB*/
1772 gpc_b16c(Pixel
*out
, const Pixel
*in
, const Background
*back
)
1783 double a
= in
->a
/65535.;
1787 out
->r
= sRGB(in
->r
* a
+ back
->dr
* a1
);
1788 out
->g
= sRGB(in
->g
* a
+ back
->dg
* a1
);
1789 out
->b
= sRGB(in
->b
* a
+ back
->db
* a1
);
1795 /* sG: convert linear RGB to sRGB grayscale */
1797 gpc_sG(Pixel
*out
, const Pixel
*in
, const Background
*back
)
1801 out
->r
= out
->g
= out
->b
= sRGB(YfromRGBint(in
->r
, in
->g
, in
->b
)/65535);
1805 /* sGp: unpremultiply RGB then convert to sRGB grayscale */
1807 gpc_sGp(Pixel
*out
, const Pixel
*in
, const Background
*back
)
1813 out
->r
= out
->g
= out
->b
= 255;
1819 out
->r
= out
->g
= out
->b
= sRGB(YfromRGBint(in
->r
, in
->g
, in
->b
)/in
->a
);
1820 out
->a
= u8d(in
->a
/ 257.);
1824 /* sCp: unpremultiply RGB then convert to sRGB */
1826 gpc_sCp(Pixel
*out
, const Pixel
*in
, const Background
*back
)
1832 out
->r
= out
->g
= out
->b
= 255;
1838 out
->r
= sRGB((double)in
->r
/ in
->a
);
1839 out
->g
= sRGB((double)in
->g
/ in
->a
);
1840 out
->b
= sRGB((double)in
->b
/ in
->a
);
1841 out
->a
= u8d(in
->a
/ 257.);
1845 /* gb16: composite linear onto background and convert to sRGB grayscale */
1846 /* (order doesn't matter, the composite and grayscale operations permute) */
1848 gpc_gb16(Pixel
*out
, const Pixel
*in
, const Background
*back
)
1851 out
->r
= out
->g
= out
->b
= back
->ig
;
1853 else if (in
->a
>= 65535)
1854 out
->r
= out
->g
= out
->b
= isRGB(in
->g
);
1858 double a
= in
->a
/ 65535.;
1862 out
->r
= out
->g
= out
->b
= sRGB(in
->g
* a
+ back
->dg
* a1
);
1868 /* cb16: composite linear onto background and convert to sRGB */
1870 gpc_cb16(Pixel
*out
, const Pixel
*in
, const Background
*back
)
1879 else if (in
->a
>= 65535)
1881 out
->r
= isRGB(in
->r
);
1882 out
->g
= isRGB(in
->g
);
1883 out
->b
= isRGB(in
->b
);
1888 double a
= in
->a
/ 65535.;
1892 out
->r
= sRGB(in
->r
* a
+ back
->dr
* a1
);
1893 out
->g
= sRGB(in
->g
* a
+ back
->dg
* a1
);
1894 out
->b
= sRGB(in
->b
* a
+ back
->db
* a1
);
1900 /* 16-bit to 16-bit conversions */
1901 /* A: set alpha to 65535 */
1903 gpc_A(Pixel
*out
, const Pixel
*in
, const Background
*back
)
1912 /* g16: convert linear RGB to linear grayscale (alpha := 65535) */
1914 gpc_g16(Pixel
*out
, const Pixel
*in
, const Background
*back
)
1917 out
->r
= out
->g
= out
->b
= u16d(YfromRGBint(in
->r
, in
->g
, in
->b
));
1921 /* g16': as 'g16' but alpha is unchanged */
1923 gpc_g16q(Pixel
*out
, const Pixel
*in
, const Background
*back
)
1926 out
->r
= out
->g
= out
->b
= u16d(YfromRGBint(in
->r
, in
->g
, in
->b
));
1930 #if ALLOW_UNUSED_GPC
1931 /* Unused functions (to hide them from GCC unused function warnings) */
1932 void (* const gpc_unused
[])
1933 (Pixel
*out
, const Pixel
*in
, const Background
*back
) =
1935 gpc_Pre
, gpc_Preq
, gpc_Glin
, gpc_Gpre
, gpc_Gprq
, gpc_nop8
, gpc_nop6
1939 /* OUT: ----- 8-bit ----- ----- 16-bit -----
1940 * IN G GA RGB RGBA G GA RGB RGBA
1941 * 8 G . . . . lin lin lin lin
1942 * 8 GA bckg . bckc . pre' pre pre' pre
1943 * 8 RGB g8 g8 . . glin glin lin lin
1944 * 8 RGBA g8b g8 bckc . gpr' gpre pre' pre
1945 * 16 G sRGB sRGB sRGB sRGB . . . .
1946 * 16 GA b16g unpg b16c unpc A . A .
1947 * 16 RGB sG sG sRGB sRGB g16 g16 . .
1948 * 16 RGBA gb16 sGp cb16 sCp g16 g16' A .
1950 * The matrix is held in an array indexed thus:
1952 * gpc_fn[out_format & BASE_FORMATS][in_format & BASE_FORMATS];
1954 /* This will produce a compile time error if the FORMAT_FLAG values don't
1955 * match the above matrix!
1957 #if PNG_FORMAT_FLAG_ALPHA == 1 && PNG_FORMAT_FLAG_COLOR == 2 &&\
1958 PNG_FORMAT_FLAG_LINEAR == 4
1959 static void (* const gpc_fn
[8/*in*/][8/*out*/])
1960 (Pixel
*out
, const Pixel
*in
, const Background
*back
) =
1962 /*out: G-8 GA-8 RGB-8 RGBA-8 G-16 GA-16 RGB-16 RGBA-16 */
1963 {gpc_noop
,gpc_noop
,gpc_noop
,gpc_noop
, gpc_Lin
, gpc_Lin
, gpc_Lin
, gpc_Lin
},
1964 {gpc_bckg
,gpc_noop
,gpc_bckc
,gpc_noop
, gpc_preq
,gpc_pre
, gpc_preq
,gpc_pre
},
1965 {gpc_g8
, gpc_g8
, gpc_noop
,gpc_noop
, gpc_glin
,gpc_glin
,gpc_lin
, gpc_lin
},
1966 {gpc_g8b
, gpc_g8
, gpc_bckc
,gpc_noop
, gpc_gprq
,gpc_gpre
,gpc_preq
,gpc_pre
},
1967 {gpc_sRGB
,gpc_sRGB
,gpc_sRGB
,gpc_sRGB
, gpc_noop
,gpc_noop
,gpc_noop
,gpc_noop
},
1968 {gpc_b16g
,gpc_unpg
,gpc_b16c
,gpc_unpc
, gpc_A
, gpc_noop
,gpc_A
, gpc_noop
},
1969 {gpc_sG
, gpc_sG
, gpc_sRGB
,gpc_sRGB
, gpc_g16
, gpc_g16
, gpc_noop
,gpc_noop
},
1970 {gpc_gb16
,gpc_sGp
, gpc_cb16
,gpc_sCp
, gpc_g16
, gpc_g16q
,gpc_A
, gpc_noop
}
1973 /* The array is repeated for the cases where both the input and output are color
1974 * mapped because then different algorithms are used.
1976 static void (* const gpc_fn_colormapped
[8/*in*/][8/*out*/])
1977 (Pixel
*out
, const Pixel
*in
, const Background
*back
) =
1979 /*out: G-8 GA-8 RGB-8 RGBA-8 G-16 GA-16 RGB-16 RGBA-16 */
1980 {gpc_noop
,gpc_noop
,gpc_noop
,gpc_noop
, gpc_lin
, gpc_lin
, gpc_lin
, gpc_lin
},
1981 {gpc_bckg
,gpc_noop
,gpc_bckc
,gpc_noop
, gpc_preq
,gpc_pre
, gpc_preq
,gpc_pre
},
1982 {gpc_g8
, gpc_g8
, gpc_noop
,gpc_noop
, gpc_glin
,gpc_glin
,gpc_lin
, gpc_lin
},
1983 {gpc_g8b
, gpc_g8
, gpc_bckc
,gpc_noop
, gpc_gprq
,gpc_gpre
,gpc_preq
,gpc_pre
},
1984 {gpc_sRGB
,gpc_sRGB
,gpc_sRGB
,gpc_sRGB
, gpc_noop
,gpc_noop
,gpc_noop
,gpc_noop
},
1985 {gpc_b16g
,gpc_unpg
,gpc_b16c
,gpc_unpc
, gpc_A
, gpc_noop
,gpc_A
, gpc_noop
},
1986 {gpc_sG
, gpc_sG
, gpc_sRGB
,gpc_sRGB
, gpc_g16
, gpc_g16
, gpc_noop
,gpc_noop
},
1987 {gpc_gb16
,gpc_sGp
, gpc_cb16
,gpc_sCp
, gpc_g16
, gpc_g16q
,gpc_A
, gpc_noop
}
1990 /* The error arrays record the error in the same matrix; 64 entries, however
1991 * the different algorithms used in libpng for colormap and direct conversions
1992 * mean that four separate matrices are used (for each combination of
1993 * colormapped and direct.)
1995 * In some cases the conversion between sRGB formats goes via a linear
1996 * intermediate; an sRGB to linear conversion (as above) is followed by a simple
1997 * linear to sRGB step with no other conversions. This is done by a separate
1998 * error array from an arbitrary 'in' format to one of the four basic outputs
1999 * (since final output is always sRGB not colormapped).
2001 * These arrays may be modified if the --accumulate flag is set during the run;
2002 * then instead of logging errors they are simply added in.
2004 * The three entries are currently for transparent, partially transparent and
2005 * opaque input pixel values. Notice that alpha should be exact in each case.
2007 * Errors in alpha should only occur when converting from a direct format
2008 * to a colormapped format, when alpha is effectively smashed (so large
2009 * errors can occur.) There should be no error in the '0' and 'opaque'
2010 * values. The fourth entry in the array is used for the alpha error (and it
2011 * should always be zero for the 'via linear' case since this is never color
2014 * Mapping to a colormap smashes the colors, it is necessary to have separate
2015 * values for these cases because they are much larger; it is very much
2016 * impossible to obtain a reasonable result, these are held in
2017 * gpc_error_to_colormap.
2019 #if PNG_FORMAT_FLAG_COLORMAP == 8 /* extra check also required */
2020 # include "pngstest-errors.h" /* machine generated */
2021 #endif /* COLORMAP flag check */
2022 #endif /* flag checks */
2026 /* Basic pixel information: */
2027 Image
* in_image
; /* Input image */
2028 const Image
* out_image
; /* Output image */
2030 /* 'background' is the value passed to the gpc_ routines, it may be NULL if
2031 * it should not be used (*this* program has an error if it crashes as a
2034 Background background_color
;
2035 const Background
* background
;
2037 /* Precalculated values: */
2038 int in_opaque
; /* Value of input alpha that is opaque */
2039 int is_palette
; /* Sample values come from the palette */
2040 int accumulate
; /* Accumlate component errors (don't log) */
2041 int output_8bit
; /* Output is 8-bit (else 16-bit) */
2043 void (*in_gp
)(Pixel
*, png_const_voidp
);
2044 void (*out_gp
)(Pixel
*, png_const_voidp
);
2046 void (*transform
)(Pixel
*out
, const Pixel
*in
, const Background
*back
);
2047 /* A function to perform the required transform */
2049 void (*from_linear
)(Pixel
*out
, const Pixel
*in
, const Background
*back
);
2050 /* For 'via_linear' transforms the final, from linear, step, else NULL */
2052 png_uint_16 error
[4];
2053 /* Three error values for transparent, partially transparent and opaque
2054 * input pixels (in turn).
2057 png_uint_16
*error_ptr
;
2058 /* Where these are stored in the static array (for 'accumulate') */
2062 /* Return a 'transform' as above for the given format conversion. */
2064 transform_from_formats(Transform
*result
, Image
*in_image
,
2065 const Image
*out_image
, png_const_colorp background
, int via_linear
)
2067 png_uint_32 in_format
, out_format
;
2068 png_uint_32 in_base
, out_base
;
2070 memset(result
, 0, sizeof *result
);
2072 /* Store the original images for error messages */
2073 result
->in_image
= in_image
;
2074 result
->out_image
= out_image
;
2076 in_format
= in_image
->image
.format
;
2077 out_format
= out_image
->image
.format
;
2079 if (in_format
& PNG_FORMAT_FLAG_LINEAR
)
2080 result
->in_opaque
= 65535;
2082 result
->in_opaque
= 255;
2084 result
->output_8bit
= (out_format
& PNG_FORMAT_FLAG_LINEAR
) == 0;
2086 result
->is_palette
= 0; /* set by caller if required */
2087 result
->accumulate
= (in_image
->opts
& ACCUMULATE
) != 0;
2089 /* The loaders (which need the ordering information) */
2090 result
->in_gp
= get_pixel(in_format
);
2091 result
->out_gp
= get_pixel(out_format
);
2093 /* Remove the ordering information: */
2094 in_format
&= BASE_FORMATS
| PNG_FORMAT_FLAG_COLORMAP
;
2095 in_base
= in_format
& BASE_FORMATS
;
2096 out_format
&= BASE_FORMATS
| PNG_FORMAT_FLAG_COLORMAP
;
2097 out_base
= out_format
& BASE_FORMATS
;
2101 /* Check for an error in this program: */
2102 if (out_format
& (PNG_FORMAT_FLAG_LINEAR
|PNG_FORMAT_FLAG_COLORMAP
))
2104 fprintf(stderr
, "internal transform via linear error 0x%x->0x%x\n",
2105 in_format
, out_format
);
2109 result
->transform
= gpc_fn
[in_base
][out_base
| PNG_FORMAT_FLAG_LINEAR
];
2110 result
->from_linear
= gpc_fn
[out_base
| PNG_FORMAT_FLAG_LINEAR
][out_base
];
2111 result
->error_ptr
= gpc_error_via_linear
[in_format
][out_format
];
2114 else if (~in_format
& out_format
& PNG_FORMAT_FLAG_COLORMAP
)
2116 /* The input is not colormapped but the output is, the errors will
2117 * typically be large (only the grayscale-no-alpha case permits preserving
2118 * even 8-bit values.)
2120 result
->transform
= gpc_fn
[in_base
][out_base
];
2121 result
->from_linear
= NULL
;
2122 result
->error_ptr
= gpc_error_to_colormap
[in_base
][out_base
];
2127 /* The caller handles the colormap->pixel value conversion, so the
2128 * transform function just gets a pixel value, however because libpng
2129 * currently contains a different implementation for mapping a colormap if
2130 * both input and output are colormapped we need different conversion
2131 * functions to deal with errors in the libpng implementation.
2133 if (in_format
& out_format
& PNG_FORMAT_FLAG_COLORMAP
)
2134 result
->transform
= gpc_fn_colormapped
[in_base
][out_base
];
2136 result
->transform
= gpc_fn
[in_base
][out_base
];
2137 result
->from_linear
= NULL
;
2138 result
->error_ptr
= gpc_error
[in_format
][out_format
];
2141 /* Follow the libpng simplified API rules to work out what to pass to the gpc
2142 * routines as a background value, if one is not required pass NULL so that
2143 * this program crashes in the even of a programming error.
2145 result
->background
= NULL
; /* default: not required */
2147 /* Rule 1: background only need be supplied if alpha is to be removed */
2148 if (in_format
& ~out_format
& PNG_FORMAT_FLAG_ALPHA
)
2150 /* The input value is 'NULL' to use the background and (otherwise) an sRGB
2151 * background color (to use a solid color). The code above uses a fixed
2152 * byte value, BUFFER_INIT8, for buffer even for 16-bit output. For
2153 * linear (16-bit) output the sRGB background color is ignored; the
2154 * composition is always on the background (so BUFFER_INIT8 * 257), except
2155 * that for the colormap (i.e. linear colormapped output) black is used.
2157 result
->background
= &result
->background_color
;
2159 if (out_format
& PNG_FORMAT_FLAG_LINEAR
|| via_linear
)
2161 if (out_format
& PNG_FORMAT_FLAG_COLORMAP
)
2163 result
->background_color
.ir
=
2164 result
->background_color
.ig
=
2165 result
->background_color
.ib
= 0;
2166 result
->background_color
.dr
=
2167 result
->background_color
.dg
=
2168 result
->background_color
.db
= 0;
2173 result
->background_color
.ir
=
2174 result
->background_color
.ig
=
2175 result
->background_color
.ib
= BUFFER_INIT8
* 257;
2176 result
->background_color
.dr
=
2177 result
->background_color
.dg
=
2178 result
->background_color
.db
= 0;
2182 else /* sRGB output */
2184 if (background
!= NULL
)
2186 if (out_format
& PNG_FORMAT_FLAG_COLOR
)
2188 result
->background_color
.ir
= background
->red
;
2189 result
->background_color
.ig
= background
->green
;
2190 result
->background_color
.ib
= background
->blue
;
2191 /* TODO: sometimes libpng uses the power law conversion here, how
2194 result
->background_color
.dr
= sRGB_to_d
[background
->red
];
2195 result
->background_color
.dg
= sRGB_to_d
[background
->green
];
2196 result
->background_color
.db
= sRGB_to_d
[background
->blue
];
2199 else /* grayscale: libpng only looks at 'g' */
2201 result
->background_color
.ir
=
2202 result
->background_color
.ig
=
2203 result
->background_color
.ib
= background
->green
;
2204 /* TODO: sometimes libpng uses the power law conversion here, how
2207 result
->background_color
.dr
=
2208 result
->background_color
.dg
=
2209 result
->background_color
.db
= sRGB_to_d
[background
->green
];
2213 else if ((out_format
& PNG_FORMAT_FLAG_COLORMAP
) == 0)
2215 result
->background_color
.ir
=
2216 result
->background_color
.ig
=
2217 result
->background_color
.ib
= BUFFER_INIT8
;
2218 /* TODO: sometimes libpng uses the power law conversion here, how
2221 result
->background_color
.dr
=
2222 result
->background_color
.dg
=
2223 result
->background_color
.db
= sRGB_to_d
[BUFFER_INIT8
];
2226 /* Else the output is colormapped and a background color must be
2227 * provided; if pngstest crashes then that is a bug in this program
2228 * (though libpng should png_error as well.)
2231 result
->background
= NULL
;
2235 if (result
->background
== NULL
)
2237 result
->background_color
.ir
=
2238 result
->background_color
.ig
=
2239 result
->background_color
.ib
= -1; /* not used */
2240 result
->background_color
.dr
=
2241 result
->background_color
.dg
=
2242 result
->background_color
.db
= 1E30
; /* not used */
2246 /* Copy the error values into the Transform: */
2247 result
->error
[0] = result
->error_ptr
[0];
2248 result
->error
[1] = result
->error_ptr
[1];
2249 result
->error
[2] = result
->error_ptr
[2];
2250 result
->error
[3] = result
->error_ptr
[3];
2254 /* Compare two pixels.
2257 static int error_to_linear = 811; * by experiment *
2258 static int error_to_linear_grayscale = 424; * by experiment *
2259 static int error_to_sRGB = 6; * by experiment *
2260 static int error_to_sRGB_grayscale = 17; * libpng error by calculation +
2262 static int error_in_compose = 2; * by experiment *
2263 static int error_in_premultiply = 1;
2265 * The following is *just* the result of a round trip from 8-bit sRGB to linear
2266 * then back to 8-bit sRGB when it is done by libpng. There are two problems:
2268 * 1) libpng currently uses a 2.2 power law with no linear segment, this results
2269 * in instability in the low values and even with 16-bit precision sRGB(1) ends
2270 * up mapping to sRGB(0) as a result of rounding in the 16-bit representation.
2271 * This gives an error of 1 in the handling of value 1 only.
2273 * 2) libpng currently uses an intermediate 8-bit linear value in gamma
2274 * correction of 8-bit values. This results in many more errors, the worse of
2275 * which is mapping sRGB(14) to sRGB(0).
2277 * The general 'error_via_linear' is more complex because of pre-multiplication,
2278 * this compounds the 8-bit errors according to the alpha value of the pixel.
2279 * As a result 256 values are pre-calculated for error_via_linear.
2282 static int error_in_libpng_gamma
;
2283 static int error_via_linear
[256]; /* Indexed by 8-bit alpha */
2286 init_error_via_linear(void)
2290 error_via_linear
[0] = 255; /* transparent pixel */
2292 for (alpha
=1; alpha
<=255; ++alpha
)
2294 /* 16-bit values less than 128.5 get rounded to 8-bit 0 and so the worst
2295 * case error arises with 16-bit 128.5, work out what sRGB
2296 * (non-associated) value generates 128.5; any value less than this is
2297 * going to map to 0, so the worst error is floor(value).
2299 * Note that errors are considerably higher (more than a factor of 2)
2300 * because libpng uses a simple power law for sRGB data at present.
2302 * Add .1 for arithmetic errors inside libpng.
2304 double v
= floor(255*pow(.5/*(128.5 * 255 / 65535)*/ / alpha
, 1/2.2)+.1);
2306 error_via_linear
[alpha
] = (int)v
;
2309 /* This is actually 14.99, but, despite the closeness to 15, 14 seems to work
2312 error_in_libpng_gamma
= 14;
2317 print_pixel(char string
[64], const Pixel
*pixel
, png_uint_32 format
)
2319 switch (format
& (PNG_FORMAT_FLAG_ALPHA
|PNG_FORMAT_FLAG_COLOR
))
2322 sprintf(string
, "%s(%d)", format_names
[format
], pixel
->g
);
2325 case PNG_FORMAT_FLAG_ALPHA
:
2326 sprintf(string
, "%s(%d,%d)", format_names
[format
], pixel
->g
,
2330 case PNG_FORMAT_FLAG_COLOR
:
2331 sprintf(string
, "%s(%d,%d,%d)", format_names
[format
],
2332 pixel
->r
, pixel
->g
, pixel
->b
);
2335 case PNG_FORMAT_FLAG_COLOR
|PNG_FORMAT_FLAG_ALPHA
:
2336 sprintf(string
, "%s(%d,%d,%d,%d)", format_names
[format
],
2337 pixel
->r
, pixel
->g
, pixel
->b
, pixel
->a
);
2341 sprintf(string
, "invalid-format");
2347 logpixel(const Transform
*transform
, png_uint_32 x
, png_uint_32 y
,
2348 const Pixel
*in
, const Pixel
*calc
, const Pixel
*out
, const char *reason
)
2350 const png_uint_32 in_format
= transform
->in_image
->image
.format
;
2351 const png_uint_32 out_format
= transform
->out_image
->image
.format
;
2353 png_uint_32 back_format
= out_format
& ~PNG_FORMAT_FLAG_ALPHA
;
2354 const char *via_linear
= "";
2356 char pixel_in
[64], pixel_calc
[64], pixel_out
[64], pixel_loc
[64];
2357 char background_info
[100];
2359 print_pixel(pixel_in
, in
, in_format
);
2360 print_pixel(pixel_calc
, calc
, out_format
);
2361 print_pixel(pixel_out
, out
, out_format
);
2363 if (transform
->is_palette
)
2364 sprintf(pixel_loc
, "palette: %lu", (unsigned long)y
);
2366 sprintf(pixel_loc
, "%lu,%lu", (unsigned long)x
, (unsigned long)y
);
2368 if (transform
->from_linear
!= NULL
)
2370 via_linear
= " (via linear)";
2371 /* And as a result the *read* format which did any background processing
2372 * was itself linear, so the background color information is also
2375 back_format
|= PNG_FORMAT_FLAG_LINEAR
;
2378 if (transform
->background
!= NULL
)
2381 char pixel_back
[64];
2383 back
.r
= transform
->background
->ir
;
2384 back
.g
= transform
->background
->ig
;
2385 back
.b
= transform
->background
->ib
;
2386 back
.a
= -1; /* not used */
2388 print_pixel(pixel_back
, &back
, back_format
);
2389 sprintf(background_info
, " on background %s", pixel_back
);
2393 background_info
[0] = 0;
2395 if (transform
->in_image
->file_name
!= transform
->out_image
->file_name
)
2397 char error_buffer
[512];
2398 sprintf(error_buffer
,
2399 "(%s) %s error%s:\n %s%s ->\n %s\n not: %s.\n"
2400 "Use --preserve and examine: ", pixel_loc
, reason
, via_linear
,
2401 pixel_in
, background_info
, pixel_out
, pixel_calc
);
2402 return logerror(transform
->in_image
, transform
->in_image
->file_name
,
2403 error_buffer
, transform
->out_image
->file_name
);
2408 char error_buffer
[512];
2409 sprintf(error_buffer
,
2410 "(%s) %s error%s:\n %s%s ->\n %s\n not: %s.\n"
2411 " The error happened when reading the original file with this format.",
2412 pixel_loc
, reason
, via_linear
, pixel_in
, background_info
, pixel_out
,
2414 return logerror(transform
->in_image
, transform
->in_image
->file_name
,
2420 cmppixel(Transform
*transform
, png_const_voidp in
, png_const_voidp out
,
2421 png_uint_32 x
, png_uint_32 y
/*or palette index*/)
2424 png_const_charp errmsg
;
2425 Pixel pixel_in
, pixel_calc
, pixel_out
;
2427 transform
->in_gp(&pixel_in
, in
);
2429 if (transform
->from_linear
== NULL
)
2430 transform
->transform(&pixel_calc
, &pixel_in
, transform
->background
);
2434 transform
->transform(&pixel_out
, &pixel_in
, transform
->background
);
2435 transform
->from_linear(&pixel_calc
, &pixel_out
, NULL
);
2438 transform
->out_gp(&pixel_out
, out
);
2440 /* Eliminate the case where the input and output values match exactly. */
2441 if (pixel_calc
.a
== pixel_out
.a
&& pixel_calc
.r
== pixel_out
.r
&&
2442 pixel_calc
.g
== pixel_out
.g
&& pixel_calc
.b
== pixel_out
.b
)
2445 /* Eliminate the case where the output pixel is transparent and the output
2446 * is 8-bit - any component values are valid. Don't check the input alpha
2447 * here to also skip the 16-bit small alpha cases.
2449 if (transform
->output_8bit
&& pixel_calc
.a
== 0 && pixel_out
.a
== 0)
2452 /* Check for alpha errors first; an alpha error can damage the components too
2453 * so avoid spurious checks on components if one is found.
2457 int err_a
= abs(pixel_calc
.a
-pixel_out
.a
);
2459 if (err_a
> transform
->error
[3])
2461 /* If accumulating check the components too */
2462 if (transform
->accumulate
)
2463 transform
->error
[3] = (png_uint_16
)err_a
;
2470 /* Now if *either* of the output alphas are 0 but alpha is within tolerance
2471 * eliminate the 8-bit component comparison.
2473 if (errmsg
== NULL
&& transform
->output_8bit
&&
2474 (pixel_calc
.a
== 0 || pixel_out
.a
== 0))
2477 if (errmsg
== NULL
) /* else just signal an alpha error */
2479 int err_r
= abs(pixel_calc
.r
- pixel_out
.r
);
2480 int err_g
= abs(pixel_calc
.g
- pixel_out
.g
);
2481 int err_b
= abs(pixel_calc
.b
- pixel_out
.b
);
2484 if ((err_r
| err_g
| err_b
) == 0)
2485 return 1; /* exact match */
2487 /* Mismatch on a component, check the input alpha */
2488 if (pixel_in
.a
>= transform
->in_opaque
)
2490 errmsg
= "opaque component";
2491 limit
= 2; /* opaque */
2494 else if (pixel_in
.a
> 0)
2496 errmsg
= "alpha component";
2497 limit
= 1; /* partially transparent */
2502 errmsg
= "transparent component (background)";
2503 limit
= 0; /* transparent */
2507 if (maxerr
< err_g
) maxerr
= err_g
;
2508 if (maxerr
< err_b
) maxerr
= err_b
;
2510 if (maxerr
<= transform
->error
[limit
])
2511 return 1; /* within the error limits */
2513 /* Handle a component mis-match; log it, just return an error code, or
2516 if (transform
->accumulate
)
2518 transform
->error
[limit
] = (png_uint_16
)maxerr
;
2519 return 1; /* to cause the caller to keep going */
2523 /* Failure to match and not accumulating, so the error must be logged. */
2524 return logpixel(transform
, x
, y
, &pixel_in
, &pixel_calc
, &pixel_out
, errmsg
);
2528 component_loc(png_byte loc
[4], png_uint_32 format
)
2530 /* Given a format return the number of channels and the location of
2533 * The mask 'loc' contains the component offset of the channels in the
2534 * following order. Note that if 'format' is grayscale the entries 1-3 must
2535 * all contain the location of the gray channel.
2544 if (format
& PNG_FORMAT_FLAG_COLOR
)
2550 # ifdef PNG_FORMAT_BGR_SUPPORTED
2551 if (format
& PNG_FORMAT_FLAG_BGR
)
2568 loc
[1] = loc
[2] = loc
[3] = 0;
2571 if (format
& PNG_FORMAT_FLAG_ALPHA
)
2573 # ifdef PNG_FORMAT_AFIRST_SUPPORTED
2574 if (format
& PNG_FORMAT_FLAG_AFIRST
)
2590 loc
[0] = 4; /* not present */
2595 /* Compare two images, the original 'a', which was written out then read back in
2596 * to * give image 'b'. The formats may have been changed.
2599 compare_two_images(Image
*a
, Image
*b
, int via_linear
,
2600 png_const_colorp background
)
2602 ptrdiff_t stridea
= a
->stride
;
2603 ptrdiff_t strideb
= b
->stride
;
2604 png_const_bytep rowa
= a
->buffer
+16;
2605 png_const_bytep rowb
= b
->buffer
+16;
2606 const png_uint_32 width
= a
->image
.width
;
2607 const png_uint_32 height
= a
->image
.height
;
2608 const png_uint_32 formata
= a
->image
.format
;
2609 const png_uint_32 formatb
= b
->image
.format
;
2610 const unsigned int a_sample
= PNG_IMAGE_SAMPLE_SIZE(formata
);
2611 const unsigned int b_sample
= PNG_IMAGE_SAMPLE_SIZE(formatb
);
2612 int alpha_added
, alpha_removed
;
2618 /* This should never happen: */
2619 if (width
!= b
->image
.width
|| height
!= b
->image
.height
)
2620 return logerror(a
, a
->file_name
, ": width x height changed: ",
2623 /* Set up the background and the transform */
2624 transform_from_formats(&tr
, a
, b
, background
, via_linear
);
2626 /* Find the first row and inter-row space. */
2627 if (!(formata
& PNG_FORMAT_FLAG_COLORMAP
) &&
2628 (formata
& PNG_FORMAT_FLAG_LINEAR
))
2631 if (!(formatb
& PNG_FORMAT_FLAG_COLORMAP
) &&
2632 (formatb
& PNG_FORMAT_FLAG_LINEAR
))
2635 if (stridea
< 0) rowa
+= (height
-1) * (-stridea
);
2636 if (strideb
< 0) rowb
+= (height
-1) * (-strideb
);
2638 /* First shortcut the two colormap case by comparing the image data; if it
2639 * matches then we expect the colormaps to match, although this is not
2640 * absolutely necessary for an image match. If the colormaps fail to match
2641 * then there is a problem in libpng.
2643 if (formata
& formatb
& PNG_FORMAT_FLAG_COLORMAP
)
2645 /* Only check colormap entries that actually exist; */
2646 png_const_bytep ppa
, ppb
;
2648 png_byte in_use
[256], amax
= 0, bmax
= 0;
2650 memset(in_use
, 0, sizeof in_use
);
2655 /* Do this the slow way to accumulate the 'in_use' flags, don't break out
2656 * of the loop until the end; this validates the color-mapped data to
2657 * ensure all pixels are valid color-map indexes.
2659 for (y
=0, match
=1; y
<height
&& match
; ++y
, ppa
+= stridea
, ppb
+= strideb
)
2663 for (x
=0; x
<width
; ++x
)
2665 png_byte bval
= ppb
[x
];
2666 png_byte aval
= ppa
[x
];
2680 /* If the buffers match then the colormaps must too. */
2683 /* Do the color-maps match, entry by entry? Only check the 'in_use'
2684 * entries. An error here should be logged as a color-map error.
2686 png_const_bytep a_cmap
= (png_const_bytep
)a
->colormap
;
2687 png_const_bytep b_cmap
= (png_const_bytep
)b
->colormap
;
2688 int result
= 1; /* match by default */
2690 /* This is used in logpixel to get the error message correct. */
2693 for (y
=0; y
<256; ++y
, a_cmap
+= a_sample
, b_cmap
+= b_sample
)
2696 /* The colormap entries should be valid, but because libpng doesn't
2697 * do any checking at present the original image may contain invalid
2698 * pixel values. These cause an error here (at present) unless
2699 * accumulating errors in which case the program just ignores them.
2701 if (y
>= a
->image
.colormap_entries
)
2703 if ((a
->opts
& ACCUMULATE
) == 0)
2706 sprintf(pindex
, "%lu[%lu]", (unsigned long)y
,
2707 (unsigned long)a
->image
.colormap_entries
);
2708 logerror(a
, a
->file_name
, ": bad pixel index: ", pindex
);
2713 else if (y
>= b
->image
.colormap_entries
)
2715 if ((b
->opts
& ACCUMULATE
) == 0)
2718 sprintf(pindex
, "%lu[%lu]", (unsigned long)y
,
2719 (unsigned long)b
->image
.colormap_entries
);
2720 logerror(b
, b
->file_name
, ": bad pixel index: ", pindex
);
2725 /* All the mismatches are logged here; there can only be 256! */
2726 else if (!cmppixel(&tr
, a_cmap
, b_cmap
, 0, y
))
2730 /* If reqested copy the error values back from the Transform. */
2731 if (a
->opts
& ACCUMULATE
)
2733 tr
.error_ptr
[0] = tr
.error
[0];
2734 tr
.error_ptr
[1] = tr
.error
[1];
2735 tr
.error_ptr
[2] = tr
.error
[2];
2736 tr
.error_ptr
[3] = tr
.error
[3];
2737 result
= 1; /* force a continue */
2743 /* else the image buffers don't match pixel-wise so compare sample values
2744 * instead, but first validate that the pixel indexes are in range (but
2745 * only if not accumulating, when the error is ignored.)
2747 else if ((a
->opts
& ACCUMULATE
) == 0)
2749 /* Check the original image first,
2750 * TODO: deal with input images with bad pixel values?
2752 if (amax
>= a
->image
.colormap_entries
)
2755 sprintf(pindex
, "%d[%lu]", amax
,
2756 (unsigned long)a
->image
.colormap_entries
);
2757 return logerror(a
, a
->file_name
, ": bad pixel index: ", pindex
);
2760 else if (bmax
>= b
->image
.colormap_entries
)
2763 sprintf(pindex
, "%d[%lu]", bmax
,
2764 (unsigned long)b
->image
.colormap_entries
);
2765 return logerror(b
, b
->file_name
, ": bad pixel index: ", pindex
);
2770 /* We can directly compare pixel values without the need to use the read
2771 * or transform support (i.e. a memory compare) if:
2773 * 1) The bit depth has not changed.
2774 * 2) RGB to grayscale has not been done (the reverse is ok; we just compare
2775 * the three RGB values to the original grayscale.)
2776 * 3) An alpha channel has not been removed from an 8-bit format, or the
2777 * 8-bit alpha value of the pixel was 255 (opaque).
2779 * If an alpha channel has been *added* then it must have the relevant opaque
2780 * value (255 or 65535).
2782 * The fist two the tests (in the order given above) (using the boolean
2783 * equivalence !a && !b == !(a || b))
2785 if (!(((formata
^ formatb
) & PNG_FORMAT_FLAG_LINEAR
) |
2786 (formata
& (formatb
^ PNG_FORMAT_FLAG_COLOR
) & PNG_FORMAT_FLAG_COLOR
)))
2788 /* Was an alpha channel changed? */
2789 const png_uint_32 alpha_changed
= (formata
^ formatb
) &
2790 PNG_FORMAT_FLAG_ALPHA
;
2792 /* Was an alpha channel removed? (The third test.) If so the direct
2793 * comparison is only possible if the input alpha is opaque.
2795 alpha_removed
= (formata
& alpha_changed
) != 0;
2797 /* Was an alpha channel added? */
2798 alpha_added
= (formatb
& alpha_changed
) != 0;
2800 /* The channels may have been moved between input and output, this finds
2801 * out how, recording the result in the btoa array, which says where in
2802 * 'a' to find each channel of 'b'. If alpha was added then btoa[alpha]
2803 * ends up as 4 (and is not used.)
2810 /* The following are used only if the formats match, except that
2811 * 'bchannels' is a flag for matching formats. btoa[x] says, for each
2812 * channel in b, where to find the corresponding value in a, for the
2813 * bchannels. achannels may be different for a gray to rgb transform
2814 * (a will be 1 or 2, b will be 3 or 4 channels.)
2816 (void)component_loc(aloc
, formata
);
2817 bchannels
= component_loc(bloc
, formatb
);
2819 /* Hence the btoa array. */
2820 for (i
=0; i
<4; ++i
) if (bloc
[i
] < 4)
2821 btoa
[bloc
[i
]] = aloc
[i
]; /* may be '4' for alpha */
2824 alpha_added
= bloc
[0]; /* location of alpha channel in image b */
2827 alpha_added
= 4; /* Won't match an image b channel */
2830 alpha_removed
= aloc
[0]; /* location of alpha channel in image a */
2839 /* Direct compare is not possible, cancel out all the corresponding local
2843 alpha_removed
= alpha_added
= 4;
2844 btoa
[3] = btoa
[2] = btoa
[1] = btoa
[0] = 4; /* 4 == not present */
2847 for (y
=0; y
<height
; ++y
, rowa
+= stridea
, rowb
+= strideb
)
2849 png_const_bytep ppa
, ppb
;
2852 for (x
=0, ppa
=rowa
, ppb
=rowb
; x
<width
; ++x
)
2854 png_const_bytep psa
, psb
;
2856 if (formata
& PNG_FORMAT_FLAG_COLORMAP
)
2857 psa
= (png_const_bytep
)a
->colormap
+ a_sample
* *ppa
++;
2859 psa
= ppa
, ppa
+= a_sample
;
2861 if (formatb
& PNG_FORMAT_FLAG_COLORMAP
)
2862 psb
= (png_const_bytep
)b
->colormap
+ b_sample
* *ppb
++;
2864 psb
= ppb
, ppb
+= b_sample
;
2866 /* Do the fast test if possible. */
2869 /* Check each 'b' channel against either the corresponding 'a'
2870 * channel or the opaque alpha value, as appropriate. If
2871 * alpha_removed value is set (not 4) then also do this only if the
2872 * 'a' alpha channel (alpha_removed) is opaque; only relevant for
2875 if (formatb
& PNG_FORMAT_FLAG_LINEAR
) /* 16-bit checks */
2877 png_const_uint_16p pua
= aligncastconst(png_const_uint_16p
, psa
);
2878 png_const_uint_16p pub
= aligncastconst(png_const_uint_16p
, psb
);
2883 if (pua
[btoa
[3]] != pub
[3]) break;
2885 if (pua
[btoa
[2]] != pub
[2]) break;
2887 if (pua
[btoa
[1]] != pub
[1]) break;
2889 if (pua
[btoa
[0]] != pub
[0]) break;
2890 if (alpha_added
!= 4 && pub
[alpha_added
] != 65535) break;
2891 continue; /* x loop */
2893 break; /* impossible */
2897 else if (alpha_removed
== 4 || psa
[alpha_removed
] == 255)
2902 if (psa
[btoa
[3]] != psb
[3]) break;
2904 if (psa
[btoa
[2]] != psb
[2]) break;
2906 if (psa
[btoa
[1]] != psb
[1]) break;
2908 if (psa
[btoa
[0]] != psb
[0]) break;
2909 if (alpha_added
!= 4 && psb
[alpha_added
] != 255) break;
2910 continue; /* x loop */
2912 break; /* impossible */
2917 /* If we get to here the fast match failed; do the slow match for this
2920 if (!cmppixel(&tr
, psa
, psb
, x
, y
) && (a
->opts
& KEEP_GOING
) == 0)
2921 return 0; /* error case */
2925 /* If reqested copy the error values back from the Transform. */
2926 if (a
->opts
& ACCUMULATE
)
2928 tr
.error_ptr
[0] = tr
.error
[0];
2929 tr
.error_ptr
[1] = tr
.error
[1];
2930 tr
.error_ptr
[2] = tr
.error
[2];
2931 tr
.error_ptr
[3] = tr
.error
[3];
2937 /* Read the file; how the read gets done depends on which of input_file and
2938 * input_memory have been set.
2941 read_file(Image
*image
, png_uint_32 format
, png_const_colorp background
)
2943 memset(&image
->image
, 0, sizeof image
->image
);
2944 image
->image
.version
= PNG_IMAGE_VERSION
;
2946 if (image
->input_memory
!= NULL
)
2948 if (!png_image_begin_read_from_memory(&image
->image
, image
->input_memory
,
2949 image
->input_memory_size
))
2950 return logerror(image
, "memory init: ", image
->file_name
, "");
2953 # ifdef PNG_STDIO_SUPPORTED
2954 else if (image
->input_file
!= NULL
)
2956 if (!png_image_begin_read_from_stdio(&image
->image
, image
->input_file
))
2957 return logerror(image
, "stdio init: ", image
->file_name
, "");
2962 if (!png_image_begin_read_from_file(&image
->image
, image
->file_name
))
2963 return logerror(image
, "file init: ", image
->file_name
, "");
2968 return logerror(image
, "unsupported file/stdio init: ",
2969 image
->file_name
, "");
2973 /* This must be set after the begin_read call: */
2974 if (image
->opts
& sRGB_16BIT
)
2975 image
->image
.flags
|= PNG_IMAGE_FLAG_16BIT_sRGB
;
2977 /* Have an initialized image with all the data we need plus, maybe, an
2978 * allocated file (myfile) or buffer (mybuffer) that need to be freed.
2982 png_uint_32 image_format
;
2984 /* Print both original and output formats. */
2985 image_format
= image
->image
.format
;
2987 if (image
->opts
& VERBOSE
)
2989 printf("%s %lu x %lu %s -> %s", image
->file_name
,
2990 (unsigned long)image
->image
.width
,
2991 (unsigned long)image
->image
.height
,
2992 format_names
[image_format
& FORMAT_MASK
],
2993 (format
& FORMAT_NO_CHANGE
) != 0 || image
->image
.format
== format
2994 ? "no change" : format_names
[format
& FORMAT_MASK
]);
2996 if (background
!= NULL
)
2997 printf(" background(%d,%d,%d)\n", background
->red
,
2998 background
->green
, background
->blue
);
3005 /* 'NO_CHANGE' combined with the color-map flag forces the base format
3006 * flags to be set on read to ensure that the original representation is
3007 * not lost in the pass through a colormap format.
3009 if ((format
& FORMAT_NO_CHANGE
) != 0)
3011 if ((format
& PNG_FORMAT_FLAG_COLORMAP
) != 0 &&
3012 (image_format
& PNG_FORMAT_FLAG_COLORMAP
) != 0)
3013 format
= (image_format
& ~BASE_FORMATS
) | (format
& BASE_FORMATS
);
3016 format
= image_format
;
3019 image
->image
.format
= format
;
3021 image
->stride
= PNG_IMAGE_ROW_STRIDE(image
->image
) + image
->stride_extra
;
3024 result
= png_image_finish_read(&image
->image
, background
,
3025 image
->buffer
+16, (png_int_32
)image
->stride
, image
->colormap
);
3027 checkbuffer(image
, image
->file_name
);
3030 return checkopaque(image
);
3033 return logerror(image
, image
->file_name
, ": image read failed", "");
3037 /* Reads from a filename, which must be in image->file_name, but uses
3038 * image->opts to choose the method. The file is always read in its native
3039 * format (the one the simplified API suggests).
3042 read_one_file(Image
*image
)
3044 if (!(image
->opts
& USE_FILE
) || (image
->opts
& USE_STDIO
))
3046 /* memory or stdio. */
3047 FILE *f
= fopen(image
->file_name
, "rb");
3051 if (image
->opts
& USE_FILE
)
3052 image
->input_file
= f
;
3056 if (fseek(f
, 0, SEEK_END
) == 0)
3058 long int cb
= ftell(f
);
3062 #ifndef __COVERITY__
3063 if ((unsigned long int)cb
<= (size_t)~(size_t)0)
3066 png_bytep b
= voidcast(png_bytep
, malloc((size_t)cb
));
3072 if (fread(b
, (size_t)cb
, 1, f
) == 1)
3075 image
->input_memory_size
= cb
;
3076 image
->input_memory
= b
;
3082 return logclose(image
, f
, image
->file_name
,
3088 return logclose(image
, f
, image
->file_name
,
3089 ": out of memory: ");
3093 return logclose(image
, f
, image
->file_name
,
3094 ": file too big for this architecture: ");
3095 /* cb is the length of the file as a (long) and
3096 * this is greater than the maximum amount of
3097 * memory that can be requested from malloc.
3102 return logclose(image
, f
, image
->file_name
,
3106 return logclose(image
, f
, image
->file_name
,
3111 return logclose(image
, f
, image
->file_name
, ": seek failed: ");
3116 return logerror(image
, image
->file_name
, ": open failed: ",
3120 return read_file(image
, FORMAT_NO_CHANGE
, NULL
);
3123 #ifdef PNG_SIMPLIFIED_WRITE_SUPPORTED
3125 write_one_file(Image
*output
, Image
*image
, int convert_to_8bit
)
3127 if (image
->opts
& FAST_WRITE
)
3128 image
->image
.flags
|= PNG_IMAGE_FLAG_FAST
;
3130 if (image
->opts
& USE_STDIO
)
3132 #ifdef PNG_SIMPLIFIED_WRITE_STDIO_SUPPORTED
3133 #ifndef __COVERITY__
3134 FILE *f
= tmpfile();
3136 /* Experimental. Coverity says tmpfile() is insecure because it
3137 * generates predictable names.
3139 * It is possible to satisfy Coverity by using mkstemp(); however,
3140 * any platform supporting mkstemp() undoubtedly has a secure tmpfile()
3141 * implementation as well, and doesn't need the fix. Note that
3142 * the fix won't work on platforms that don't support mkstemp().
3144 * https://www.securecoding.cert.org/confluence/display/c/
3145 * FIO21-C.+Do+not+create+temporary+files+in+shared+directories
3146 * says that most historic implementations of tmpfile() provide
3147 * only a limited number of possible temporary file names
3148 * (usually 26) before file names are recycled. That article also
3149 * provides a secure solution that unfortunately depends upon mkstemp().
3151 char tmpfile
[] = "pngstest-XXXXXX";
3155 filedes
= mkstemp(tmpfile
);
3160 f
= fdopen(filedes
,"w+");
3161 /* Hide the filename immediately and ensure that the file does
3162 * not exist after the program ends
3164 (void) unlink(tmpfile
);
3170 if (png_image_write_to_stdio(&image
->image
, f
, convert_to_8bit
,
3171 image
->buffer
+16, (png_int_32
)image
->stride
, image
->colormap
))
3176 initimage(output
, image
->opts
, "tmpfile", image
->stride_extra
);
3177 output
->input_file
= f
;
3178 if (!checkopaque(image
))
3183 return logclose(image
, f
, "tmpfile", ": flush: ");
3189 return logerror(image
, "tmpfile", ": write failed", "");
3194 return logerror(image
, "tmpfile", ": open: ", strerror(errno
));
3195 #else /* SIMPLIFIED_WRITE_STDIO */
3196 return logerror(image
, "tmpfile", ": open: unsupported", "");
3197 #endif /* SIMPLIFIED_WRITE_STDIO */
3200 else if (image
->opts
& USE_FILE
)
3202 #ifdef PNG_SIMPLIFIED_WRITE_STDIO_SUPPORTED
3203 static int counter
= 0;
3206 sprintf(name
, "%s%d.png", tmpf
, ++counter
);
3208 if (png_image_write_to_file(&image
->image
, name
, convert_to_8bit
,
3209 image
->buffer
+16, (png_int_32
)image
->stride
, image
->colormap
))
3211 initimage(output
, image
->opts
, output
->tmpfile_name
,
3212 image
->stride_extra
);
3213 /* Afterwards, or freeimage will delete it! */
3214 strcpy(output
->tmpfile_name
, name
);
3216 if (!checkopaque(image
))
3221 return logerror(image
, name
, ": write failed", "");
3222 #else /* SIMPLIFIED_WRITE_STDIO */
3223 return logerror(image
, "stdio", ": open: unsupported", "");
3224 #endif /* SIMPLIFIED_WRITE_STDIO */
3227 else /* use memory */
3229 png_alloc_size_t size
;
3231 if (png_image_write_get_memory_size(image
->image
, size
, convert_to_8bit
,
3232 image
->buffer
+16, (png_int_32
)image
->stride
, image
->colormap
))
3234 /* This is non-fatal but ignoring it was causing serious problems in
3235 * the macro to be ignored:
3237 if (size
> PNG_IMAGE_PNG_SIZE_MAX(image
->image
))
3238 return logerror(image
, "memory", ": PNG_IMAGE_SIZE_MAX wrong", "");
3240 initimage(output
, image
->opts
, "memory", image
->stride_extra
);
3241 output
->input_memory
= malloc(size
);
3243 if (output
->input_memory
!= NULL
)
3245 output
->input_memory_size
= size
;
3247 if (png_image_write_to_memory(&image
->image
, output
->input_memory
,
3248 &output
->input_memory_size
, convert_to_8bit
, image
->buffer
+16,
3249 (png_int_32
)image
->stride
, image
->colormap
))
3251 /* This is also non-fatal but it safes safer to error out anyway:
3253 if (size
!= output
->input_memory_size
)
3254 return logerror(image
, "memory", ": memory size wrong", "");
3258 return logerror(image
, "memory", ": write failed", "");
3262 return logerror(image
, "memory", ": out of memory", "");
3266 return logerror(image
, "memory", ": get size:", "");
3269 /* 'output' has an initialized temporary image, read this back in and compare
3270 * this against the original: there should be no change since the original
3271 * format was written unmodified unless 'convert_to_8bit' was specified.
3272 * However, if the original image was color-mapped, a simple read will zap
3273 * the linear, color and maybe alpha flags, this will cause spurious failures
3274 * under some circumstances.
3276 if (read_file(output
, image
->image
.format
| FORMAT_NO_CHANGE
, NULL
))
3278 png_uint_32 original_format
= image
->image
.format
;
3280 if (convert_to_8bit
)
3281 original_format
&= ~PNG_FORMAT_FLAG_LINEAR
;
3283 if ((output
->image
.format
& BASE_FORMATS
) !=
3284 (original_format
& BASE_FORMATS
))
3285 return logerror(image
, image
->file_name
, ": format changed on read: ",
3288 return compare_two_images(image
, output
, 0/*via linear*/, NULL
);
3292 return logerror(output
, output
->tmpfile_name
,
3293 ": read of new file failed", "");
3298 testimage(Image
*image
, png_uint_32 opts
, format_list
*pf
)
3303 /* Copy the original data, stealing it from 'image' */
3312 image
->input_file
= NULL
;
3313 image
->input_memory
= NULL
;
3314 image
->input_memory_size
= 0;
3315 image
->tmpfile_name
[0] = 0;
3318 png_uint_32 counter
;
3325 /* Use the low bit of 'counter' to indicate whether or not to do alpha
3326 * removal with a background color or by composting onto the image; this
3327 * step gets skipped if it isn't relevant
3329 for (counter
=0; counter
<2*FORMAT_COUNT
; ++counter
)
3330 if (format_isset(pf
, counter
>> 1))
3332 png_uint_32 format
= counter
>> 1;
3334 png_color background_color
;
3335 png_colorp background
= NULL
;
3337 /* If there is a format change that removes the alpha channel then
3338 * the background is relevant. If the output is 8-bit color-mapped
3339 * then a background color *must* be provided, otherwise there are
3340 * two tests to do - one with a color, the other with NULL. The
3341 * NULL test happens second.
3343 if ((counter
& 1) == 0)
3345 if ((format
& PNG_FORMAT_FLAG_ALPHA
) == 0 &&
3346 (image
->image
.format
& PNG_FORMAT_FLAG_ALPHA
) != 0)
3348 /* Alpha/transparency will be removed, the background is
3349 * relevant: make it a color the first time
3351 random_color(&background_color
);
3352 background
= &background_color
;
3354 /* BUT if the output is to a color-mapped 8-bit format then
3355 * the background must always be a color, so increment 'counter'
3356 * to skip the NULL test.
3358 if ((format
& PNG_FORMAT_FLAG_COLORMAP
) != 0 &&
3359 (format
& PNG_FORMAT_FLAG_LINEAR
) == 0)
3363 /* Otherwise an alpha channel is not being eliminated, just leave
3364 * background NULL and skip the (counter & 1) NULL test.
3369 /* else just use NULL for background */
3372 copy
.opts
= opts
; /* in case read_file needs to change it */
3374 result
= read_file(©
, format
, background
);
3378 /* Make sure the file just read matches the original file. */
3379 result
= compare_two_images(image
, ©
, 0/*via linear*/, background
);
3383 # ifdef PNG_SIMPLIFIED_WRITE_SUPPORTED
3384 /* Write the *copy* just made to a new file to make sure the write
3385 * side works ok. Check the conversion to sRGB if the copy is
3389 result
= write_one_file(&output
, ©
, 0/*convert to 8bit*/);
3393 /* Validate against the original too; the background is needed here
3394 * as well so that compare_two_images knows what color was used.
3396 result
= compare_two_images(image
, &output
, 0, background
);
3400 if ((format
& PNG_FORMAT_FLAG_LINEAR
) != 0 &&
3401 (format
& PNG_FORMAT_FLAG_COLORMAP
) == 0)
3403 /* 'output' is linear, convert to the corresponding sRGB format.
3406 result
= write_one_file(&output
, ©
, 1/*convert to 8bit*/);
3410 /* This may involve a conversion via linear; in the ideal world
3411 * this would round-trip correctly, but libpng 1.5.7 is not the
3412 * ideal world so allow a drift (error_via_linear).
3414 * 'image' has an alpha channel but 'output' does not then there
3415 * will a strip-alpha-channel operation (because 'output' is
3416 * linear), handle this by composing on black when doing the
3419 result
= compare_two_images(image
, &output
, 1/*via_linear*/,
3424 # endif /* PNG_SIMPLIFIED_WRITE_SUPPORTED */
3436 test_one_file(const char *file_name
, format_list
*formats
, png_uint_32 opts
,
3437 int stride_extra
, int log_pass
)
3442 if (!(opts
& NO_RESEED
))
3443 reseed(); /* ensure that the random numbers don't depend on file order */
3445 initimage(&image
, opts
, file_name
, stride_extra
);
3446 result
= read_one_file(&image
);
3448 result
= testimage(&image
, opts
, formats
);
3451 /* Ensure that stderr is flushed into any log file */
3462 # ifndef PNG_SIMPLIFIED_WRITE_SUPPORTED
3463 printf(" (no write)");
3467 printf(" %s\n", file_name
);
3468 /* stdout may not be line-buffered if it is piped to a file, so: */
3479 main(int argc
, char **argv
)
3481 png_uint_32 opts
= FAST_WRITE
| STRICT
;
3482 format_list formats
;
3483 const char *touch
= NULL
;
3486 int stride_extra
= 0;
3490 #if PNG_LIBPNG_VER >= 10700
3491 /* This error should not exist in 1.7 or later: */
3497 init_error_via_linear();
3499 format_init(&formats
);
3500 reseed(); /* initialize random number seeds */
3502 for (c
=1; c
<argc
; ++c
)
3504 const char *arg
= argv
[c
];
3506 if (strcmp(arg
, "--log") == 0)
3508 else if (strcmp(arg
, "--fresh") == 0)
3510 memset(gpc_error
, 0, sizeof gpc_error
);
3511 memset(gpc_error_via_linear
, 0, sizeof gpc_error_via_linear
);
3513 else if (strcmp(arg
, "--file") == 0)
3514 # ifdef PNG_STDIO_SUPPORTED
3517 return SKIP
; /* skipped: no support */
3519 else if (strcmp(arg
, "--memory") == 0)
3521 else if (strcmp(arg
, "--stdio") == 0)
3522 # ifdef PNG_STDIO_SUPPORTED
3525 return SKIP
; /* skipped: no support */
3527 else if (strcmp(arg
, "--name") == 0)
3529 else if (strcmp(arg
, "--verbose") == 0)
3531 else if (strcmp(arg
, "--quiet") == 0)
3533 else if (strcmp(arg
, "--preserve") == 0)
3534 opts
|= KEEP_TMPFILES
;
3535 else if (strcmp(arg
, "--nopreserve") == 0)
3536 opts
&= ~KEEP_TMPFILES
;
3537 else if (strcmp(arg
, "--keep-going") == 0)
3539 else if (strcmp(arg
, "--fast") == 0)
3541 else if (strcmp(arg
, "--slow") == 0)
3542 opts
&= ~FAST_WRITE
;
3543 else if (strcmp(arg
, "--accumulate") == 0)
3545 else if (strcmp(arg
, "--redundant") == 0)
3547 else if (strcmp(arg
, "--stop") == 0)
3548 opts
&= ~KEEP_GOING
;
3549 else if (strcmp(arg
, "--strict") == 0)
3551 else if (strcmp(arg
, "--nostrict") == 0)
3553 else if (strcmp(arg
, "--sRGB-16bit") == 0)
3555 else if (strcmp(arg
, "--linear-16bit") == 0)
3556 opts
&= ~sRGB_16BIT
;
3557 else if (strcmp(arg
, "--noreseed") == 0)
3559 else if (strcmp(arg
, "--fault-gbg-warning") == 0)
3561 else if (strcmp(arg
, "--tmpfile") == 0)
3565 if (strlen(argv
[++c
]) >= sizeof tmpf
)
3568 fprintf(stderr
, "%s: %s is too long for a temp file prefix\n",
3573 /* Safe: checked above */
3574 strncpy(tmpf
, argv
[c
], sizeof (tmpf
)-1);
3580 fprintf(stderr
, "%s: %s requires a temporary file prefix\n",
3585 else if (strcmp(arg
, "--touch") == 0)
3593 fprintf(stderr
, "%s: %s requires a file name argument\n",
3598 else if (arg
[0] == '+')
3600 png_uint_32 format
= formatof(arg
+1);
3602 if (format
> FORMAT_COUNT
)
3605 format_set(&formats
, format
);
3607 else if (arg
[0] == '-' && arg
[1] != 0 && (arg
[1] != '0' || arg
[2] != 0))
3610 fprintf(stderr
, "%s: unknown option: %s\n", argv
[0], arg
);
3615 if (format_is_initial(&formats
))
3616 format_default(&formats
, redundant
);
3620 const int term
= (arg
[1] == '0' ? 0 : '\n');
3621 unsigned int ich
= 0;
3623 /* Loop reading files, use a static buffer to simplify this and just
3624 * stop if the name gets to long.
3626 static char buffer
[4096];
3632 /* Don't allow '\0' in file names, and terminate with '\n' or,
3633 * for -0, just '\0' (use -print0 to find to make this work!)
3635 if (ch
== EOF
|| ch
== term
|| ch
== 0)
3639 if (ich
> 0 && !test_one_file(buffer
, &formats
, opts
,
3640 stride_extra
, log_pass
))
3647 --ich
; /* so that the increment below sets it to 0 again */
3651 buffer
[ich
] = (char)ch
;
3652 } while (++ich
< sizeof buffer
);
3658 fprintf(stderr
, "%s...%s: file name too long\n", buffer
,
3664 else if (!test_one_file(arg
, &formats
, opts
, stride_extra
, log_pass
))
3669 if (opts
& ACCUMULATE
)
3673 printf("/* contrib/libtests/pngstest-errors.h\n");
3675 printf(" * BUILT USING:" PNG_HEADER_VERSION_STRING
);
3677 printf(" * This code is released under the libpng license.\n");
3678 printf(" * For conditions of distribution and use, see the disclaimer\n");
3679 printf(" * and license in png.h\n");
3681 printf(" * THIS IS A MACHINE GENERATED FILE: do not edit it directly!\n");
3682 printf(" * Instead run:\n");
3684 printf(" * pngstest --accumulate\n");
3686 printf(" * on as many PNG files as possible; at least PNGSuite and\n");
3687 printf(" * contrib/libtests/testpngs.\n");
3690 printf("static png_uint_16 gpc_error[16/*in*/][16/*out*/][4/*a*/] =\n");
3692 for (in
=0; in
<16; ++in
)
3695 printf(" { /* input: %s */\n ", format_names
[in
]);
3696 for (out
=0; out
<16; ++out
)
3700 for (alpha
=0; alpha
<4; ++alpha
)
3702 printf(" %d", gpc_error
[in
][out
][alpha
]);
3703 if (alpha
< 3) putchar(',');
3709 if (out
% 4 == 3) printf("\n ");
3721 printf("static png_uint_16 gpc_error_via_linear[16][4/*out*/][4] =\n");
3723 for (in
=0; in
<16; ++in
)
3726 printf(" { /* input: %s */\n ", format_names
[in
]);
3727 for (out
=0; out
<4; ++out
)
3731 for (alpha
=0; alpha
<4; ++alpha
)
3733 printf(" %d", gpc_error_via_linear
[in
][out
][alpha
]);
3734 if (alpha
< 3) putchar(',');
3749 printf("static png_uint_16 gpc_error_to_colormap[8/*i*/][8/*o*/][4] =\n");
3751 for (in
=0; in
<8; ++in
)
3754 printf(" { /* input: %s */\n ", format_names
[in
]);
3755 for (out
=0; out
<8; ++out
)
3759 for (alpha
=0; alpha
<4; ++alpha
)
3761 printf(" %d", gpc_error_to_colormap
[in
][out
][alpha
]);
3762 if (alpha
< 3) putchar(',');
3768 if (out
% 4 == 3) printf("\n ");
3779 printf("/* END MACHINE GENERATED */\n");
3782 if (retval
== 0 && touch
!= NULL
)
3784 FILE *fsuccess
= fopen(touch
, "wt");
3786 if (fsuccess
!= NULL
)
3789 fprintf(fsuccess
, "PNG simple API tests succeeded\n");
3791 error
= ferror(fsuccess
);
3793 if (fclose(fsuccess
) || error
)
3796 fprintf(stderr
, "%s: write failed\n", touch
);
3804 fprintf(stderr
, "%s: open failed\n", touch
);
3812 #else /* !PNG_SIMPLIFIED_READ_SUPPORTED */
3815 fprintf(stderr
, "pngstest: no read support in libpng, test skipped\n");
3816 /* So the test is skipped: */
3819 #endif /* PNG_SIMPLIFIED_READ_SUPPORTED */