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Diffstat (limited to 'converter/other/pngtopnm.c')
| -rw-r--r-- | converter/other/pngtopnm.c | 1255 |
1 files changed, 0 insertions, 1255 deletions
diff --git a/converter/other/pngtopnm.c b/converter/other/pngtopnm.c deleted file mode 100644 index 205df654..00000000 --- a/converter/other/pngtopnm.c +++ /dev/null @@ -1,1255 +0,0 @@ -/* -** pngtopnm.c - -** read a Portable Network Graphics file and produce a PNM. -** -** Copyright (C) 1995,1998 by Alexander Lehmann <alex@hal.rhein-main.de> -** and Willem van Schaik <willem@schaik.com> -** -** Permission to use, copy, modify, and distribute this software and its -** documentation for any purpose and without fee is hereby granted, provided -** that the above copyright notice appear in all copies and that both that -** copyright notice and this permission notice appear in supporting -** documentation. This software is provided "as is" without express or -** implied warranty. -** -** modeled after giftopnm by David Koblas and -** with lots of bits pasted from libpng.txt by Guy Eric Schalnat -*/ - -#ifndef PNMTOPNG_WARNING_LEVEL -# define PNMTOPNG_WARNING_LEVEL 0 /* use 0 for backward compatibility, */ -#endif /* 2 for warnings (1 == error) */ - -#include <assert.h> -#include <math.h> -#include <float.h> -#include <png.h> /* includes zlib.h and setjmp.h */ -#define VERSION "2.37.4 (5 December 1999) +netpbm" - -#include "pm_c_util.h" -#include "mallocvar.h" -#include "nstring.h" -#include "shhopt.h" -#include "pnm.h" - -#if PNG_LIBPNG_VER >= 10500 -#error Your PNG library (<png.h>) is incompatible with this Netpbm source code. -#error You need either an older PNG library (older than 1.5) or -#error newer Netpbm source code (at least 10.55) -#endif - -/* A hack until we can remove direct access to png_info from the program */ -#if PNG_LIBPNG_VER >= 10400 -#define TRANS_ALPHA trans_alpha -#else -#define TRANS_ALPHA trans -#endif - - -enum alpha_handling {ALPHA_NONE, ALPHA_ONLY, ALPHA_MIX}; - -struct cmdlineInfo { - /* All the information the user supplied in the command line, - in a form easy for the program to use. - */ - const char *inputFilespec; /* '-' if stdin */ - unsigned int verbose; - enum alpha_handling alpha; - const char * background; - float gamma; /* -1.0 means unspecified */ - const char * text; - unsigned int time; -}; - - -typedef struct { -/*---------------------------------------------------------------------------- - A color in a format compatible with the PNG library. - - Note that the PNG library declares types png_color and png_color_16 - which are similar. ------------------------------------------------------------------------------*/ - png_uint_16 r; - png_uint_16 g; - png_uint_16 b; -} pngcolor; - - -static png_uint_16 maxval; -static bool verbose; - - -static void -parseCommandLine(int argc, - const char ** argv, - struct cmdlineInfo * cmdlineP ) { -/*---------------------------------------------------------------------------- - Parse program command line described in Unix standard form by argc - and argv. Return the information in the options as *cmdlineP. - - If command line is internally inconsistent (invalid options, etc.), - issue error message to stderr and abort program. - - Note that the strings we return are stored in the storage that - was passed to us as the argv array. We also trash *argv. ------------------------------------------------------------------------------*/ - optEntry * option_def; - /* Instructions to optParseOptions3 on how to parse our options. - */ - optStruct3 opt; - - unsigned int option_def_index; - - unsigned int alphaSpec, mixSpec, backgroundSpec, gammaSpec, textSpec; - - MALLOCARRAY(option_def, 100); - - option_def_index = 0; /* incremented by OPTENT3 */ - OPTENT3(0, "verbose", OPT_FLAG, NULL, - &cmdlineP->verbose, 0); - OPTENT3(0, "alpha", OPT_FLAG, NULL, - &alphaSpec, 0); - OPTENT3(0, "mix", OPT_FLAG, NULL, - &mixSpec, 0); - OPTENT3(0, "background", OPT_STRING, &cmdlineP->background, - &backgroundSpec, 0); - OPTENT3(0, "gamma", OPT_FLOAT, &cmdlineP->gamma, - &gammaSpec, 0); - OPTENT3(0, "text", OPT_STRING, &cmdlineP->text, - &textSpec, 0); - OPTENT3(0, "time", OPT_FLAG, NULL, - &cmdlineP->time, 0); - - opt.opt_table = option_def; - opt.short_allowed = FALSE; /* We have no short (old-fashioned) options */ - opt.allowNegNum = FALSE; /* We have no parms that are negative numbers */ - - optParseOptions3(&argc, (char **)argv, opt, sizeof(opt), 0); - /* Uses and sets argc, argv, and some of *cmdlineP and others. */ - - - if (alphaSpec && mixSpec) - pm_error("You cannot specify both -alpha and -mix"); - else if (alphaSpec) - cmdlineP->alpha = ALPHA_ONLY; - else if (mixSpec) - cmdlineP->alpha = ALPHA_MIX; - else - cmdlineP->alpha = ALPHA_NONE; - - if (backgroundSpec && !mixSpec) - pm_error("-background is useless without -mix"); - - if (!backgroundSpec) - cmdlineP->background = NULL; - - if (!gammaSpec) - cmdlineP->gamma = -1.0; - - if (!textSpec) - cmdlineP->text = NULL; - - if (argc-1 < 1) - cmdlineP->inputFilespec = "-"; - else if (argc-1 == 1) - cmdlineP->inputFilespec = argv[1]; - else - pm_error("Program takes at most one argument: input file name. " - "you specified %d", argc-1); -} - - - -static void -pngtopnmErrorHandler(png_structp const png_ptr, - png_const_charp const msg) { - - jmp_buf * jmpbufP; - - /* this function, aside from the extra step of retrieving the "error - pointer" (below) and the fact that it exists within the application - rather than within libpng, is essentially identical to libpng's - default error handler. The second point is critical: since both - setjmp() and longjmp() are called from the same code, they are - guaranteed to have compatible notions of how big a jmp_buf is, - regardless of whether _BSD_SOURCE or anything else has (or has not) - been defined. - */ - - pm_message("fatal libpng error: %s", msg); - - jmpbufP = png_get_error_ptr(png_ptr); - - if (!jmpbufP) { - /* we are completely hosed now */ - pm_error("EXTREMELY fatal error: jmpbuf unrecoverable; terminating."); - } - - longjmp(*jmpbufP, 1); -} - - - -struct pngx { - png_structp png_ptr; - png_infop info_ptr; -}; - - - -static void -pngx_createRead(struct pngx ** const pngxPP, - jmp_buf * const jmpbufP) { - - struct pngx * pngxP; - - MALLOCVAR(pngxP); - - if (!pngxP) - pm_error("Failed to allocate memory for PNG object"); - else { - pngxP->png_ptr = png_create_read_struct( - PNG_LIBPNG_VER_STRING, - jmpbufP, pngtopnmErrorHandler, NULL); - - if (!pngxP->png_ptr) - pm_error("cannot allocate main libpng structure (png_ptr)"); - else { - pngxP->info_ptr = png_create_info_struct(pngxP->png_ptr); - - if (!pngxP->info_ptr) - pm_error("cannot allocate libpng info structure (info_ptr)"); - else - *pngxPP = pngxP; - } - } -} - - - -static void -pngx_destroy(struct pngx * const pngxP) { - - png_destroy_read_struct(&pngxP->png_ptr, &pngxP->info_ptr, NULL); - - free(pngxP); -} - - - -static bool -pngx_chunkIsPresent(struct pngx * const pngxP, - uint32_t const chunkType) { - - return png_get_valid(pngxP->png_ptr, pngxP->info_ptr, chunkType); -} - - - -static void -verifyFileIsPng(FILE * const ifP, - size_t * const consumedByteCtP) { - - unsigned char buffer[4]; - size_t bytesRead; - - bytesRead = fread(buffer, 1, sizeof(buffer), ifP); - if (bytesRead != sizeof(buffer)) - pm_error("input file is empty or too short"); - - if (png_sig_cmp(buffer, (png_size_t) 0, (png_size_t) sizeof(buffer)) != 0) - pm_error("input file is not a PNG file " - "(does not have the PNG signature in its first 4 bytes)"); - else - *consumedByteCtP = bytesRead; -} - - - -static unsigned int -computePngLineSize(struct pngx * const pngxP) { - - unsigned int const bytesPerSample = - pngxP->info_ptr->bit_depth == 16 ? 2 : 1; - - unsigned int samplesPerPixel; - - switch (pngxP->info_ptr->color_type) { - case PNG_COLOR_TYPE_GRAY_ALPHA: samplesPerPixel = 2; break; - case PNG_COLOR_TYPE_RGB: samplesPerPixel = 3; break; - case PNG_COLOR_TYPE_RGB_ALPHA: samplesPerPixel = 4; break; - default: samplesPerPixel = 1; - } - - if (UINT_MAX / bytesPerSample / samplesPerPixel < pngxP->info_ptr->width) - pm_error("Width %u of PNG is uncomputably large", - (unsigned int)pngxP->info_ptr->width); - - return pngxP->info_ptr->width * bytesPerSample * samplesPerPixel; -} - - - -static void -allocPngRaster(struct pngx * const pngxP, - png_byte *** const pngImageP) { - - unsigned int const lineSize = computePngLineSize(pngxP); - - png_byte ** pngImage; - unsigned int row; - - MALLOCARRAY(pngImage, pngxP->info_ptr->height); - - if (pngImage == NULL) - pm_error("couldn't allocate space for %u PNG raster rows", - (unsigned int)pngxP->info_ptr->height); - - for (row = 0; row < pngxP->info_ptr->height; ++row) { - MALLOCARRAY(pngImage[row], lineSize); - if (pngImage[row] == NULL) - pm_error("couldn't allocate space for %uth row of PNG raster", - row); - } - *pngImageP = pngImage; -} - - - -static void -freePngRaster(png_byte ** const pngRaster, - struct pngx * const pngxP) { - - unsigned int row; - - for (row = 0; row < pngxP->info_ptr->height; ++row) - free(pngRaster[row]); - - free(pngRaster); -} - - - -static void -readPng(struct pngx * const pngxP, - FILE * const ifP, - png_byte *** const pngRasterP) { - - size_t sigByteCt; - png_byte ** pngRaster; - - verifyFileIsPng(ifP, &sigByteCt); - - /* Declare that we already read the signature bytes */ - png_set_sig_bytes(pngxP->png_ptr, (int)sigByteCt); - - png_init_io(pngxP->png_ptr, ifP); - - png_read_info(pngxP->png_ptr, pngxP->info_ptr); - - allocPngRaster(pngxP, &pngRaster); - - if (pngxP->info_ptr->bit_depth < 8) - png_set_packing(pngxP->png_ptr); - - png_read_image(pngxP->png_ptr, pngRaster); - - png_read_end(pngxP->png_ptr, pngxP->info_ptr); - - /* Note that some of info_ptr is not defined until png_read_end() - completes. That's because it comes from chunks that are at the - end of the stream. - */ - - *pngRasterP = pngRaster; -} - - - -static png_uint_16 -get_png_val(const png_byte ** const pp, - int const bit_depth) { - - png_uint_16 c; - - if (bit_depth == 16) - c = (*((*pp)++)) << 8; - else - c = 0; - - c |= (*((*pp)++)); - - return c; -} - - - -static bool -isGrayscale(pngcolor const color) { - - return color.r == color.g && color.r == color.b; -} - - - -static void -setXel(xel * const xelP, - pngcolor const foreground, - pngcolor const background, - enum alpha_handling const alpha_handling, - png_uint_16 const alpha) { - - if (alpha_handling == ALPHA_ONLY) { - PNM_ASSIGN1(*xelP, alpha); - } else { - if ((alpha_handling == ALPHA_MIX) && (alpha != maxval)) { - double const opacity = (double)alpha / maxval; - double const transparency = 1.0 - opacity; - - pngcolor mix; - - mix.r = foreground.r * opacity + background.r * transparency + 0.5; - mix.g = foreground.g * opacity + background.g * transparency + 0.5; - mix.b = foreground.b * opacity + background.b * transparency + 0.5; - PPM_ASSIGN(*xelP, mix.r, mix.g, mix.b); - } else - PPM_ASSIGN(*xelP, foreground.r, foreground.g, foreground.b); - } -} - - - -static png_uint_16 -gamma_correct(png_uint_16 const v, - float const g) { - - if (g != -1.0) - return (png_uint_16) ROUNDU(pow((double) v / maxval, (1.0 / g)) * - maxval); - else - return v; -} - - - -static bool -iscolor(png_color const c) { - - return c.red != c.green || c.green != c.blue; -} - - - -static void -saveText(struct pngx * const pngxP, - FILE * const tfP) { - - png_info * const info_ptr = pngxP->info_ptr; - - unsigned int i; - - for (i = 0 ; i < info_ptr->num_text; ++i) { - unsigned int j; - j = 0; - - while (info_ptr->text[i].key[j] != '\0' && - info_ptr->text[i].key[j] != ' ') - ++j; - - if (info_ptr->text[i].key[j] != ' ') { - fprintf(tfP, "%s", info_ptr->text[i].key); - for (j = strlen (info_ptr->text[i].key); j < 15; ++j) - putc(' ', tfP); - } else { - fprintf(tfP, "\"%s\"", info_ptr->text[i].key); - for (j = strlen (info_ptr->text[i].key); j < 13; ++j) - putc(' ', tfP); - } - putc(' ', tfP); /* at least one space between key and text */ - - for (j = 0; j < info_ptr->text[i].text_length; ++j) { - putc(info_ptr->text[i].text[j], tfP); - if (info_ptr->text[i].text[j] == '\n') { - unsigned int k; - for (k = 0; k < 16; ++k) - putc(' ', tfP); - } - } - putc('\n', tfP); - } -} - - - -static void -showTime(struct pngx * const pngxP) { - - static const char * const month[] = { - "", "January", "February", "March", "April", "May", "June", - "July", "August", "September", "October", "November", "December" - }; - - if (pngxP->info_ptr->valid & PNG_INFO_tIME) { - if (pngxP->info_ptr->mod_time.month < 1 || - pngxP->info_ptr->mod_time.month >= ARRAY_SIZE(month)) { - pm_message("tIME chunk in PNG input is invalid; " - "modification time of image is unknown. " - "The month value, which should be in the range " - "1-12, is %u", pngxP->info_ptr->mod_time.month); - } else - pm_message("modification time: %02d %s %d %02d:%02d:%02d", - pngxP->info_ptr->mod_time.day, - month[pngxP->info_ptr->mod_time.month], - pngxP->info_ptr->mod_time.year, - pngxP->info_ptr->mod_time.hour, - pngxP->info_ptr->mod_time.minute, - pngxP->info_ptr->mod_time.second); - } -} - - - -static void -dumpPngInfo(struct pngx * const pngxP) { - - png_info * const info_ptr = pngxP->info_ptr; - const char *type_string; - const char *filter_string; - - switch (info_ptr->color_type) { - case PNG_COLOR_TYPE_GRAY: - type_string = "gray"; - break; - - case PNG_COLOR_TYPE_GRAY_ALPHA: - type_string = "gray+alpha"; - break; - - case PNG_COLOR_TYPE_PALETTE: - type_string = "palette"; - break; - - case PNG_COLOR_TYPE_RGB: - type_string = "truecolor"; - break; - - case PNG_COLOR_TYPE_RGB_ALPHA: - type_string = "truecolor+alpha"; - break; - } - - switch (info_ptr->filter_type) { - case PNG_FILTER_TYPE_BASE: - asprintfN(&filter_string, "base filter"); - break; - default: - asprintfN(&filter_string, "unknown filter type %d", - info_ptr->filter_type); - } - - pm_message("reading a %ldw x %ldh image, %d bit%s", - info_ptr->width, info_ptr->height, - info_ptr->bit_depth, info_ptr->bit_depth > 1 ? "s" : ""); - pm_message("%s, %s, %s", - type_string, - info_ptr->interlace_type ? - "Adam7 interlaced" : "not interlaced", - filter_string); - pm_message("background {index, gray, red, green, blue} = " - "{%d, %d, %d, %d, %d}", - info_ptr->background.index, - info_ptr->background.gray, - info_ptr->background.red, - info_ptr->background.green, - info_ptr->background.blue); - - strfree(filter_string); - - if (info_ptr->valid & PNG_INFO_tRNS) - pm_message("tRNS chunk (transparency): %u entries", - info_ptr->num_trans); - else - pm_message("tRNS chunk (transparency): not present"); - - if (info_ptr->valid & PNG_INFO_gAMA) - pm_message("gAMA chunk (image gamma): gamma = %4.2f", info_ptr->gamma); - else - pm_message("gAMA chunk (image gamma): not present"); - - if (info_ptr->valid & PNG_INFO_sBIT) - pm_message("sBIT chunk: present"); - else - pm_message("sBIT chunk: not present"); - - if (info_ptr->valid & PNG_INFO_cHRM) - pm_message("cHRM chunk: present"); - else - pm_message("cHRM chunk: not present"); - - if (info_ptr->valid & PNG_INFO_PLTE) - pm_message("PLTE chunk: %d entries", info_ptr->num_palette); - else - pm_message("PLTE chunk: not present"); - - if (info_ptr->valid & PNG_INFO_bKGD) - pm_message("bKGD chunk: present"); - else - pm_message("bKGD chunk: not present"); - - if (info_ptr->valid & PNG_INFO_PLTE) - pm_message("hIST chunk: present"); - else - pm_message("hIST chunk: not present"); - - if (info_ptr->valid & PNG_INFO_pHYs) - pm_message("pHYs chunk: present"); - else - pm_message("pHYs chunk: not present"); - - if (info_ptr->valid & PNG_INFO_oFFs) - pm_message("oFFs chunk: present"); - else - pm_message("oFFs chunk: not present"); - - if (info_ptr->valid & PNG_INFO_tIME) - pm_message("tIME chunk: present"); - else - pm_message("tIME chunk: not present"); - - if (info_ptr->valid & PNG_INFO_pCAL) - pm_message("pCAL chunk: present"); - else - pm_message("pCAL chunk: not present"); - - if (info_ptr->valid & PNG_INFO_sRGB) - pm_message("sRGB chunk: present"); - else - pm_message("sRGB chunk: not present"); -} - - - -static const png_color_16 * -transColor(struct pngx * const pngxP) { - - png_bytep trans; - int numTrans; - png_color_16 * transColor; - - assert(pngx_chunkIsPresent(pngxP, PNG_INFO_tRNS)); - - png_get_tRNS(pngxP->png_ptr, pngxP->info_ptr, - &trans, &numTrans, &transColor); - - return transColor; -} - - - -static bool -isTransparentColor(pngcolor const color, - struct pngx * const pngxP, - double const totalgamma) { -/*---------------------------------------------------------------------------- - Return TRUE iff pixels of color 'color' are supposed to be transparent - everywhere they occur. Assume it's an RGB image. - - 'color' has been gamma-corrected. ------------------------------------------------------------------------------*/ - bool retval; - - if (pngx_chunkIsPresent(pngxP, PNG_INFO_tRNS)) { - const png_color_16 * const transColorP = transColor(pngxP); - - /* It seems odd that libpng lets you get gamma-corrected pixel - values, but not gamma-corrected transparency or background - values. But as that is the case, we have to gamma-correct - the transparency values. - - Note that because we compare the gamma-corrected values and - there may be many-to-one mapping of uncorrected to corrected - values, more pixels may be transparent than what the user - intended. - - We could fix this by not letting libpng gamma-correct the - pixels, and just do it ourselves. - */ - - switch (pngxP->info_ptr->color_type) { - case PNG_COLOR_TYPE_GRAY: - retval = color.r == gamma_correct(transColorP->gray, totalgamma); - break; - default: - retval = - color.r == gamma_correct(transColorP->red, totalgamma) && - color.g == gamma_correct(transColorP->green, totalgamma) && - color.b == gamma_correct(transColorP->blue, totalgamma); - } - } else - retval = FALSE; - - return retval; -} - - - -static void -setupGammaCorrection(struct pngx * const pngxP, - float const displaygamma, - float * const totalgammaP) { - - if (displaygamma == -1.0) - *totalgammaP = -1.0; - else { - float imageGamma; - if (pngxP->info_ptr->valid & PNG_INFO_gAMA) - imageGamma = pngxP->info_ptr->gamma; - else { - if (verbose) - pm_message("PNG doesn't specify image gamma. Assuming 1.0"); - imageGamma = 1.0; - } - - if (fabs(displaygamma * imageGamma - 1.0) < .01) { - *totalgammaP = -1.0; - if (verbose) - pm_message("image gamma %4.2f matches " - "display gamma %4.2f. No conversion.", - imageGamma, displaygamma); - } else { - png_set_gamma(pngxP->png_ptr, displaygamma, imageGamma); - *totalgammaP = imageGamma * displaygamma; - /* in case of gamma-corrections, sBIT's as in the - PNG-file are not valid anymore - */ - pngxP->info_ptr->valid &= ~PNG_INFO_sBIT; - if (verbose) - pm_message("image gamma is %4.2f, " - "converted for display gamma of %4.2f", - imageGamma, displaygamma); - } - } -} - - - -static bool -paletteHasPartialTransparency(png_info * const info_ptr) { - - bool retval; - - if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE) { - if (info_ptr->valid & PNG_INFO_tRNS) { - bool foundGray; - unsigned int i; - - for (i = 0, foundGray = FALSE; - i < info_ptr->num_trans && !foundGray; - ++i) { - if (info_ptr->TRANS_ALPHA[i] != 0 && - info_ptr->TRANS_ALPHA[i] != maxval) { - foundGray = TRUE; - } - } - retval = foundGray; - } else - retval = FALSE; - } else - retval = FALSE; - - return retval; -} - - - -static void -setupSignificantBits(struct pngx * const pngxP, - enum alpha_handling const alpha, - png_uint_16 * const maxvalP, - int * const errorLevelP) { -/*---------------------------------------------------------------------------- - Figure out what maxval would best express the information in the PNG - described by *pngxP, with 'alpha' telling which information in the PNG we - care about (image or alpha mask). - - Return the result as *maxvalP. ------------------------------------------------------------------------------*/ - png_info * const info_ptr = pngxP->info_ptr; - - /* Initial assumption of maxval */ - if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE) { - if (alpha == ALPHA_ONLY) { - if (info_ptr->color_type == PNG_COLOR_TYPE_GRAY || - info_ptr->color_type == PNG_COLOR_TYPE_RGB) - /* The alpha mask will be all opaque, so maxval 1 is plenty */ - *maxvalP = 1; - else if (paletteHasPartialTransparency(info_ptr)) - /* Use same maxval as PNG transparency palette for simplicity*/ - *maxvalP = 255; - else - /* A common case, so we conserve bits */ - *maxvalP = 1; - } else - /* Use same maxval as PNG palette for simplicity */ - *maxvalP = 255; - } else { - *maxvalP = (1l << info_ptr->bit_depth) - 1; - } - - /* sBIT handling is very tricky. If we are extracting only the - image, we can use the sBIT info for grayscale and color images, - if the three values agree. If we extract the transparency/alpha - mask, sBIT is irrelevant for trans and valid for alpha. If we - mix both, the multiplication may result in values that require - the normal bit depth, so we will use the sBIT info only for - transparency, if we know that only solid and fully transparent - is used - */ - - if (info_ptr->valid & PNG_INFO_sBIT) { - switch (alpha) { - case ALPHA_MIX: - if (info_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA || - info_ptr->color_type == PNG_COLOR_TYPE_GRAY_ALPHA) - break; - if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE && - (info_ptr->valid & PNG_INFO_tRNS)) { - - bool trans_mix; - unsigned int i; - trans_mix = TRUE; - for (i = 0; i < info_ptr->num_trans; ++i) - if (info_ptr->TRANS_ALPHA[i] != 0 && info_ptr->TRANS_ALPHA[i] != 255) { - trans_mix = FALSE; - break; - } - if (!trans_mix) - break; - } - - /* else fall though to normal case */ - - case ALPHA_NONE: - if ((info_ptr->color_type == PNG_COLOR_TYPE_PALETTE || - info_ptr->color_type == PNG_COLOR_TYPE_RGB || - info_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA) && - (info_ptr->sig_bit.red != info_ptr->sig_bit.green || - info_ptr->sig_bit.red != info_ptr->sig_bit.blue) && - alpha == ALPHA_NONE) { - pm_message("This program cannot handle " - "different bit depths for color channels"); - pm_message("writing file with %d bit resolution", - info_ptr->bit_depth); - *errorLevelP = PNMTOPNG_WARNING_LEVEL; - } else { - if ((info_ptr->color_type == PNG_COLOR_TYPE_PALETTE) && - (info_ptr->sig_bit.red < 255)) { - unsigned int i; - for (i = 0; i < info_ptr->num_palette; ++i) { - info_ptr->palette[i].red >>= - (8 - info_ptr->sig_bit.red); - info_ptr->palette[i].green >>= - (8 - info_ptr->sig_bit.green); - info_ptr->palette[i].blue >>= - (8 - info_ptr->sig_bit.blue); - } - *maxvalP = (1l << info_ptr->sig_bit.red) - 1; - if (verbose) - pm_message ("image has fewer significant bits, " - "writing file with %d bits per channel", - info_ptr->sig_bit.red); - } else - if ((info_ptr->color_type == PNG_COLOR_TYPE_RGB || - info_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA) && - (info_ptr->sig_bit.red < info_ptr->bit_depth)) { - png_set_shift(pngxP->png_ptr, &(info_ptr->sig_bit)); - *maxvalP = (1l << info_ptr->sig_bit.red) - 1; - if (verbose) - pm_message("image has fewer significant bits, " - "writing file with %d " - "bits per channel", - info_ptr->sig_bit.red); - } else - if ((info_ptr->color_type == PNG_COLOR_TYPE_GRAY || - info_ptr->color_type == - PNG_COLOR_TYPE_GRAY_ALPHA) && - (info_ptr->sig_bit.gray < info_ptr->bit_depth)) { - png_set_shift(pngxP->png_ptr, &info_ptr->sig_bit); - *maxvalP = (1l << info_ptr->sig_bit.gray) - 1; - if (verbose) - pm_message("image has fewer significant bits, " - "writing file with %d bits", - info_ptr->sig_bit.gray); - } - } - break; - - case ALPHA_ONLY: - if ((info_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA || - info_ptr->color_type == PNG_COLOR_TYPE_GRAY_ALPHA) && - (info_ptr->sig_bit.gray < info_ptr->bit_depth)) { - png_set_shift(pngxP->png_ptr, &info_ptr->sig_bit); - if (verbose) - pm_message ("image has fewer significant bits, " - "writing file with %d bits", - info_ptr->sig_bit.alpha); - *maxvalP = (1l << info_ptr->sig_bit.alpha) - 1; - } - break; - - } - } -} - - - -static bool -imageHasColor(struct pngx * const pngxP) { - - bool retval; - - if (pngxP->info_ptr->color_type == PNG_COLOR_TYPE_GRAY || - pngxP->info_ptr->color_type == PNG_COLOR_TYPE_GRAY_ALPHA) - - retval = FALSE; - else if (pngxP->info_ptr->color_type == PNG_COLOR_TYPE_PALETTE) { - bool foundColor; - unsigned int i; - - for (i = 0, foundColor = FALSE; - i < pngxP->info_ptr->num_palette && !foundColor; - ++i) { - if (iscolor(pngxP->info_ptr->palette[i])) - foundColor = TRUE; - } - retval = foundColor; - } else - retval = TRUE; - - return retval; -} - - - -static void -determineOutputType(struct pngx * const pngxP, - enum alpha_handling const alphaHandling, - pngcolor const bgColor, - xelval const maxval, - int * const pnmTypeP) { - - if (alphaHandling != ALPHA_ONLY && - (imageHasColor(pngxP) || !isGrayscale(bgColor))) - *pnmTypeP = PPM_TYPE; - else { - if (maxval > 1) - *pnmTypeP = PGM_TYPE; - else - *pnmTypeP = PBM_TYPE; - } -} - - - -static void -getBackgroundColor(struct pngx * const pngxP, - const char * const requestedColor, - float const totalgamma, - xelval const maxval, - pngcolor * const bgColorP) { -/*---------------------------------------------------------------------------- - Figure out what the background color should be. If the user requested - a particular color ('requestedColor' not null), that's the one. - Otherwise, if the PNG specifies a background color, that's the one. - And otherwise, it's white. ------------------------------------------------------------------------------*/ - if (requestedColor) { - /* Background was specified from the command-line; we always - use that. I chose to do no gamma-correction in this case; - which is a bit arbitrary. - */ - pixel const backcolor = ppm_parsecolor(requestedColor, maxval); - - bgColorP->r = PPM_GETR(backcolor); - bgColorP->g = PPM_GETG(backcolor); - bgColorP->b = PPM_GETB(backcolor); - - } else if (pngxP->info_ptr->valid & PNG_INFO_bKGD) { - /* didn't manage to get libpng to work (bugs?) concerning background - processing, therefore we do our own. - */ - switch (pngxP->info_ptr->color_type) { - case PNG_COLOR_TYPE_GRAY: - case PNG_COLOR_TYPE_GRAY_ALPHA: - bgColorP->r = bgColorP->g = bgColorP->b = - gamma_correct(pngxP->info_ptr->background.gray, totalgamma); - break; - case PNG_COLOR_TYPE_PALETTE: { - png_color const rawBgcolor = - pngxP->info_ptr->palette[pngxP->info_ptr->background.index]; - bgColorP->r = gamma_correct(rawBgcolor.red, totalgamma); - bgColorP->g = gamma_correct(rawBgcolor.green, totalgamma); - bgColorP->b = gamma_correct(rawBgcolor.blue, totalgamma); - } - break; - case PNG_COLOR_TYPE_RGB: - case PNG_COLOR_TYPE_RGB_ALPHA: { - png_color_16 const rawBgcolor = pngxP->info_ptr->background; - - bgColorP->r = gamma_correct(rawBgcolor.red, totalgamma); - bgColorP->g = gamma_correct(rawBgcolor.green, totalgamma); - bgColorP->b = gamma_correct(rawBgcolor.blue, totalgamma); - } - break; - } - } else - /* when no background given, we use white [from version 2.37] */ - bgColorP->r = bgColorP->g = bgColorP->b = maxval; -} - - - -static void -warnNonsquarePixels(struct pngx * const pngxP, - int * const errorLevelP) { - - if (pngxP->info_ptr->valid & PNG_INFO_pHYs) { - float const r = - (float)pngxP->info_ptr->x_pixels_per_unit / - pngxP->info_ptr->y_pixels_per_unit; - - if (r != 1.0) { - pm_message ("warning - non-square pixels; " - "to fix do a 'pamscale -%cscale %g'", - r < 1.0 ? 'x' : 'y', - r < 1.0 ? 1.0 / r : r ); - *errorLevelP = PNMTOPNG_WARNING_LEVEL; - } - } -} - - - -#define GET_PNG_VAL(p) get_png_val(&(p), pngxP->info_ptr->bit_depth) - - - -static void -makeXelRow(xel * const xelrow, - xelval const maxval, - int const pnmType, - struct pngx * const pngxP, - const png_byte * const pngRasterRow, - pngcolor const bgColor, - enum alpha_handling const alphaHandling, - double const totalgamma) { - - const png_byte * pngPixelP; - unsigned int col; - - pngPixelP = &pngRasterRow[0]; /* initial value */ - for (col = 0; col < pngxP->info_ptr->width; ++col) { - switch (pngxP->info_ptr->color_type) { - case PNG_COLOR_TYPE_GRAY: { - pngcolor fgColor; - fgColor.r = fgColor.g = fgColor.b = GET_PNG_VAL(pngPixelP); - setXel(&xelrow[col], fgColor, bgColor, alphaHandling, - isTransparentColor(fgColor, pngxP, totalgamma) ? - 0 : maxval); - } - break; - - case PNG_COLOR_TYPE_GRAY_ALPHA: { - pngcolor fgColor; - png_uint_16 alpha; - - fgColor.r = fgColor.g = fgColor.b = GET_PNG_VAL(pngPixelP); - alpha = GET_PNG_VAL(pngPixelP); - setXel(&xelrow[col], fgColor, bgColor, alphaHandling, alpha); - } - break; - - case PNG_COLOR_TYPE_PALETTE: { - png_uint_16 const index = GET_PNG_VAL(pngPixelP); - png_color const paletteColor = pngxP->info_ptr->palette[index]; - - pngcolor fgColor; - - fgColor.r = paletteColor.red; - fgColor.g = paletteColor.green; - fgColor.b = paletteColor.blue; - - setXel(&xelrow[col], fgColor, bgColor, alphaHandling, - (pngxP->info_ptr->valid & PNG_INFO_tRNS) && - index < pngxP->info_ptr->num_trans ? - pngxP->info_ptr->TRANS_ALPHA[index] : maxval); - } - break; - - case PNG_COLOR_TYPE_RGB: { - pngcolor fgColor; - - fgColor.r = GET_PNG_VAL(pngPixelP); - fgColor.g = GET_PNG_VAL(pngPixelP); - fgColor.b = GET_PNG_VAL(pngPixelP); - setXel(&xelrow[col], fgColor, bgColor, alphaHandling, - isTransparentColor(fgColor, pngxP, totalgamma) ? - 0 : maxval); - } - break; - - case PNG_COLOR_TYPE_RGB_ALPHA: { - pngcolor fgColor; - png_uint_16 alpha; - - fgColor.r = GET_PNG_VAL(pngPixelP); - fgColor.g = GET_PNG_VAL(pngPixelP); - fgColor.b = GET_PNG_VAL(pngPixelP); - alpha = GET_PNG_VAL(pngPixelP); - setXel(&xelrow[col], fgColor, bgColor, alphaHandling, alpha); - } - break; - - default: - pm_error("unknown PNG color type: %d", - pngxP->info_ptr->color_type); - } - } -} - - - -static void -writePnm(FILE * const ofP, - xelval const maxval, - int const pnmType, - struct pngx * const pngxP, - png_byte ** const pngRaster, - pngcolor const bgColor, - enum alpha_handling const alphaHandling, - double const totalgamma) { -/*---------------------------------------------------------------------------- - Write a PNM of either the image or the alpha mask, according to - 'alphaHandling' that is in the PNG image described by *pngxP and - pngRaster[][]. - - 'pnmType' and 'maxval' are of the output image. - - Use background color 'bgColor' in the output if the PNG is such that a - background color is needed. ------------------------------------------------------------------------------*/ - int const plainFalse = 0; - - xel * xelrow; - unsigned int row; - - if (verbose) - pm_message("writing a %s file (maxval=%u)", - pnmType == PBM_TYPE ? "PBM" : - pnmType == PGM_TYPE ? "PGM" : - pnmType == PPM_TYPE ? "PPM" : - "UNKNOWN!", - maxval); - - xelrow = pnm_allocrow(pngxP->info_ptr->width); - - pnm_writepnminit(stdout, - pngxP->info_ptr->width, pngxP->info_ptr->height, maxval, - pnmType, plainFalse); - - for (row = 0; row < pngxP->info_ptr->height; ++row) { - makeXelRow(xelrow, maxval, pnmType, pngxP, pngRaster[row], bgColor, - alphaHandling, totalgamma); - - pnm_writepnmrow(ofP, xelrow, pngxP->info_ptr->width, maxval, - pnmType, plainFalse); - } - pnm_freerow (xelrow); -} - - - -static void -convertpng(FILE * const ifP, - FILE * const tfP, - struct cmdlineInfo const cmdline, - int * const errorLevelP) { - - png_byte ** pngRaster; - int pnmType; - pngcolor bgColor; - float totalgamma; - jmp_buf jmpbuf; - struct pngx * pngxP; - - *errorLevelP = 0; - - if (setjmp(jmpbuf)) - pm_error ("setjmp returns error condition"); - - pngx_createRead(&pngxP, &jmpbuf); - - readPng(pngxP, ifP, &pngRaster); - - if (verbose) - dumpPngInfo(pngxP); - - if (cmdline.time) - showTime(pngxP); - if (tfP) - saveText(pngxP, tfP); - - warnNonsquarePixels(pngxP, errorLevelP); - - setupGammaCorrection(pngxP, cmdline.gamma, &totalgamma); - - setupSignificantBits(pngxP, cmdline.alpha, &maxval, errorLevelP); - - getBackgroundColor(pngxP, cmdline.background, totalgamma, maxval, - &bgColor); - - determineOutputType(pngxP, cmdline.alpha, bgColor, maxval, &pnmType); - - writePnm(stdout, maxval, pnmType, pngxP, pngRaster, bgColor, - cmdline.alpha, totalgamma); - - fflush(stdout); - - freePngRaster(pngRaster, pngxP); - - pngx_destroy(pngxP); -} - - - -int -main(int argc, const char *argv[]) { - - struct cmdlineInfo cmdline; - FILE * ifP; - FILE * tfP; - int errorLevel; - - pm_proginit(&argc, argv); - - parseCommandLine(argc, argv, &cmdline); - - verbose = cmdline.verbose; - - ifP = pm_openr(cmdline.inputFilespec); - - if (cmdline.text) - tfP = pm_openw(cmdline.text); - else - tfP = NULL; - - convertpng(ifP, tfP, cmdline, &errorLevel); - - if (tfP) - pm_close(tfP); - - pm_close(ifP); - pm_close(stdout); - - return errorLevel; -} |