From 3438f87fadae82e7d12ed356a00a1b66d849295a Mon Sep 17 00:00:00 2001 From: Glenn Randers-Pehrson Date: Sat, 22 Jul 2000 22:48:43 -0500 Subject: [PATCH] Imported from pngcrush-1.4.8.tar --- pngcrush.c | 66 +++++++++++++++++++++++++++++++++++++++++------------- 1 file changed, 50 insertions(+), 16 deletions(-) diff --git a/pngcrush.c b/pngcrush.c index 20d5454b3..c23cb70da 100644 --- a/pngcrush.c +++ b/pngcrush.c @@ -16,11 +16,11 @@ * occasionally creating Linux executables. */ -#define PNGCRUSH_VERSION "1.4.7" +#define PNGCRUSH_VERSION "1.4.8" /* -#define PNGCRUSH_COUNT_COLORS */ +#define PNGCRUSH_COUNT_COLORS /* * COPYRIGHT NOTICE, DISCLAIMER, AND LICENSE: @@ -57,6 +57,11 @@ */ /* Change log: + * + * Version 1.4.8 (built with libpng-1.0.8rc1) + * + * Detect and remove all-opaque alpha channel. + * Detect and reduce all-gray truecolor images to grayscale. * * Version 1.4.7 (built with libpng-1.0.8rc1) * @@ -251,6 +256,8 @@ * Rearrange palette to put most-used color first and transparent color * second (see ImageMagick 5.1.1 and later). * Finish pplt (partial palette) feature. + * Take care that sBIT and bKGD data aren't lost when reducing images + * from truecolor to grayscale. * * Version 1.4.*: Use an alternate write function for the trial passes, that * simply counts bytes rather than actually writing to a file, to save wear @@ -270,6 +277,10 @@ #define PNG_INTERNAL #include "png.h" +/* we don't need the some of the extra libpng transformations + * so they are ifdef'ed out in a special version of pngconf.h, which + * includes pngcrush.h and is included by png.h */ + #ifndef PNGCRUSH_LIBPNG_VER # define PNGCRUSH_LIBPNG_VER PNG_LIBPNG_VER #endif @@ -278,7 +289,8 @@ int main() { - printf("Version numbers in pngcrush.h and png.h do not match\n"); + printf("Version numbers in pngcrush.h (%d) and png.h (%d) do not match\n", + PNGCRUSH_LIBPNG_VER, PNG_LIBPNG_VER); } #else @@ -287,6 +299,8 @@ int main() { printf("Sorry, but pngcrush needs libpng version 0.96 or later\n"); + printf("You have built pngcrush with libpng version %s\n", + PNG_LIBPNG_VER_STRING); } #else @@ -330,10 +344,6 @@ main() #define P1 if(verbose > 1)printf #define P2 if(verbose > 2)printf -/* we don't need the extra libpng transformations - * so they are ifdef'ed out in a special version of pngconf.h */ - - #if (PNG_LIBPNG_VER > 95) /* so we can load pngcrush with pre-1.0.6 versions of libpng */ @@ -440,9 +450,7 @@ int best; char buffer[256]; char *str_return; -/* The cexcept documentation recommends putting the following three lines in a - * separate header file, but it appears to work with them embedded here. - * There is only one "Throw" and it is in this file. */ +/* Set up the "cexcept" Try/Throw/Catch exception handler. */ #include "cexcept.h" define_exception_type(const char *); extern struct exception_context the_exception_context[1]; @@ -745,6 +753,7 @@ void png_crush_pause(void) } #ifdef __riscos +/* The riscos/acorn support was contributed by Darren Salt. */ #include static int fileexists(const char *name) { @@ -2092,6 +2101,7 @@ main(int argc, char *argv[]) number_of_open_files++; alpha_status=count_colors(fpin); + alpha_status = alpha_status; /* silence compiler warning. */ FCLOSE(fpin); @@ -2563,6 +2573,15 @@ main(int argc, char *argv[]) if((color_type == 2 || color_type == 6 || color_type == 3) && (output_color_type == 0 || output_color_type == 4)) { + if(verbose > 0 && first_trial) + { + if(reduce_to_gray) + fprintf(STDERR, + " Reducing all-gray truecolor image to grayscale.\n"); + else + fprintf(STDERR, + " Reducing truecolor image to grayscale.\n"); + } #ifdef PNG_FIXED_POINT_SUPPORTED png_set_rgb_to_gray_fixed(read_ptr, 1, -1, -1); #else @@ -2589,7 +2608,12 @@ main(int argc, char *argv[]) (output_color_type != 4 && output_color_type != 6)) { if(verbose > 0 && first_trial) - fprintf(STDERR, " Stripping existing alpha channel.\n"); + { + if(it_is_opaque) + fprintf(STDERR, " Stripping opaque alpha channel.\n"); + else + fprintf(STDERR, " Stripping existing alpha channel.\n"); + } #ifdef PNG_READ_STRIP_ALPHA_SUPPORTED png_set_strip_alpha(read_ptr); #endif @@ -2687,6 +2711,11 @@ main(int argc, char *argv[]) } if (have_bkgd) { + /* If we are reducing an RGB image to grayscale, but the + background color isn't gray, the green channel is written. + That's not spec-compliant. We should really check for + a non-gray bKGD and refuse to do the reduction if one is + present. */ png_color_16 backgd; png_color_16p background = &backgd; background->red=bkgd_red; @@ -3072,6 +3101,9 @@ main(int argc, char *argv[]) { png_color_8p sig_bit; + /* If we are reducing a truecolor PNG to grayscale, and the + RGB sBIT values aren't identical, we'll lose sBIT info. */ + if (png_get_sBIT(read_ptr, read_info_ptr, &sig_bit)) { if(keep_chunk("sBIT",argv)) @@ -3800,14 +3832,14 @@ png_measure_idat(png_structp png_ptr) png_debug(1, "in png_read_info\n"); { - png_byte png_sign[8] = {137, 80, 78, 71, 13, 10, 26, 10}; + png_byte png_signature[8] = {137, 80, 78, 71, 13, 10, 26, 10}; - png_read_data(png_ptr, png_sign, 8); + png_read_data(png_ptr, png_signature, 8); png_set_sig_bytes(png_ptr, 8); - if (png_sig_cmp(png_sign, 0, 8)) + if (png_sig_cmp(png_signature, 0, 8)) { - if (png_sig_cmp(png_sign, 0, 4)) + if (png_sig_cmp(png_signature, 0, 4)) png_error(png_ptr, "Not a PNG file"); else png_error(png_ptr, "PNG file corrupted by ASCII conversion"); @@ -4336,8 +4368,10 @@ count_colors(FILE *fpin) P2 ("Finished checking alphas, result=%d\n",result); if(reduce_to_gray) P1 ("The truecolor image is all gray and will be reduced.\n"); + if(color_type == 0 || color_type == 2) + it_is_opaque=0; if(it_is_opaque) - P1 ("The image is opaque.\n"); + P1 ("The image is opaque and the alpha channel will be removed.\n"); } return (result); }