diff options
Diffstat (limited to 'converter/other/pngtopam.c')
| -rw-r--r-- | converter/other/pngtopam.c | 1237 |
1 files changed, 754 insertions, 483 deletions
diff --git a/converter/other/pngtopam.c b/converter/other/pngtopam.c index 89ac100a..8743174e 100644 --- a/converter/other/pngtopam.c +++ b/converter/other/pngtopam.c @@ -21,65 +21,52 @@ #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 <png.h> +/* Becaues of a design error in png.h, you must not #include <setjmp.h> before + <png.h>. If you do, png.h won't compile. +*/ +#include <setjmp.h> +#include <zlib.h> + #include "pm_c_util.h" #include "mallocvar.h" #include "nstring.h" #include "shhopt.h" #include "pam.h" +#include "pngx.h" -/* A hack until we can remove direct access to png_info from the program */ -#if PNG_LIBPNG_VER >= 10400 -#define trans_values trans_color -#define TRANS_ALPHA trans_alpha -#else -#define TRANS_ALPHA trans -#endif - -typedef struct _jmpbuf_wrapper { - jmp_buf jmpbuf; -} jmpbuf_wrapper; +enum AlphaHandling {ALPHA_NONE, ALPHA_ONLY, ALPHA_MIX, ALPHA_IN}; -enum alpha_handling {ALPHA_NONE, ALPHA_ONLY, ALPHA_MIX, ALPHA_IN}; +typedef struct { + bool needCorrection; + double gamma; +} GammaCorrection; -struct cmdlineInfo { +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 */ + const char * inputFileName; /* '-' if stdin */ unsigned int verbose; - enum alpha_handling alpha; + enum AlphaHandling alpha; const char * background; - float gamma; /* -1.0 means unspecified */ + unsigned int gammaSpec; + float gamma; const char * text; unsigned int time; + unsigned int byrow; }; -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 jmpbuf_wrapper pngtopnm_jmpbuf_struct; + static void parseCommandLine(int argc, const char ** argv, - struct cmdlineInfo * cmdlineP ) { + struct CmdlineInfo * cmdlineP ) { /*---------------------------------------------------------------------------- Parse program command line described in Unix standard form by argc and argv. Return the information in the options as *cmdlineP. @@ -91,14 +78,14 @@ parseCommandLine(int argc, was passed to us as the argv array. We also trash *argv. -----------------------------------------------------------------------------*/ optEntry * option_def; - /* Instructions to optParseOptions3 on how to parse our options. + /* Instructions to pm_optParseOptions3 on how to parse our options. */ optStruct3 opt; unsigned int option_def_index; unsigned int alphaSpec, alphapamSpec, mixSpec, - backgroundSpec, gammaSpec, textSpec; + backgroundSpec, textSpec; MALLOCARRAY(option_def, 100); @@ -114,17 +101,19 @@ parseCommandLine(int argc, OPTENT3(0, "background", OPT_STRING, &cmdlineP->background, &backgroundSpec, 0); OPTENT3(0, "gamma", OPT_FLOAT, &cmdlineP->gamma, - &gammaSpec, 0); + &cmdlineP->gammaSpec, 0); OPTENT3(0, "text", OPT_STRING, &cmdlineP->text, &textSpec, 0); OPTENT3(0, "time", OPT_FLAG, NULL, &cmdlineP->time, 0); + OPTENT3(0, "byrow", OPT_FLAG, NULL, + &cmdlineP->byrow, 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); + pm_optParseOptions3(&argc, (char **)argv, opt, sizeof(opt), 0); /* Uses and sets argc, argv, and some of *cmdlineP and others. */ @@ -145,16 +134,13 @@ parseCommandLine(int argc, if (!backgroundSpec) cmdlineP->background = NULL; - if (!gammaSpec) - cmdlineP->gamma = -1.0; - if (!textSpec) cmdlineP->text = NULL; if (argc-1 < 1) - cmdlineP->inputFilespec = "-"; + cmdlineP->inputFileName = "-"; else if (argc-1 == 1) - cmdlineP->inputFilespec = argv[1]; + cmdlineP->inputFileName = argv[1]; else pm_error("Program takes at most one argument: input file name. " "you specified %d", argc-1); @@ -162,18 +148,299 @@ parseCommandLine(int argc, +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 pngcolor +pngcolorFrom16(png_color_16 const arg) { + + pngcolor retval; + + retval.r = arg.red; + retval.g = arg.green; + retval.b = arg.blue; + + return retval; +} + + + +static pngcolor +pngcolorFromByte(png_color const arg) { + + pngcolor retval; + + retval.r = arg.red; + retval.g = arg.green; + retval.b = arg.blue; + + return retval; +} + + + +static bool +pngColorEqual(pngcolor const comparand, + pngcolor const comparator) { + + return (comparand.r == comparator.r + && comparand.g == comparator.g + && comparand.b == comparator.b); +} + + + +static png_uint_16 +gammaCorrect(png_uint_16 const uncorrected, + GammaCorrection const gamma, + png_uint_16 const maxval) { + + if (gamma.needCorrection) { + double const uncorrectedN = (double) uncorrected / maxval; + return (png_uint_16) + ROUNDU(pow(uncorrectedN, (1.0 / gamma.gamma)) * maxval); + } else + return uncorrected; +} + + + +static pngcolor +gammaCorrectColor(pngcolor const color, + GammaCorrection const gamma, + png_uint_16 const maxval) { + + pngcolor retval; + + retval.r = gammaCorrect(color.r, gamma, maxval); + + return retval; +} + + + +static unsigned int +computePngLineSize(struct pngx * const pngxP) { + + unsigned int const bytesPerSample = + pngx_bitDepth(pngxP) == 16 ? 2 : 1; + + unsigned int samplesPerPixel; + + switch (pngx_colorType(pngxP)) { + 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 < pngx_imageWidth(pngxP)) + pm_error("Width %u of PNG is uncomputably large", + pngx_imageWidth(pngxP)); + + return pngx_imageWidth(pngxP) * 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, pngx_imageHeight(pngxP)); + + if (pngImage == NULL) + pm_error("couldn't allocate index space for %u PNG raster rows. " + "Try -byrow, which needs only 1 row of buffer space. ", + pngx_imageHeight(pngxP)); + + for (row = 0; row < pngx_imageHeight(pngxP); ++row) { + MALLOCARRAY(pngImage[row], lineSize); + if (pngImage[row] == NULL) + pm_error("couldn't allocate space for %uth row of PNG raster. " + "Try -byrow, which needs only 1 row of buffer space. ", + row); + } + *pngImageP = pngImage; +} + + + +static void +freePngRaster(png_byte ** const pngRaster, + struct pngx * const pngxP) { + + unsigned int row; + + for (row = 0; row < pngx_imageHeight(pngxP); ++row) + free(pngRaster[row]); + + free(pngRaster); +} + + + +typedef struct { +/*---------------------------------------------------------------------------- + This is an object for reading the raster of the PNG, a row at a time. +-----------------------------------------------------------------------------*/ + struct pngx * pngxP; + png_byte ** pngRaster; + /* The entire raster of the PNG. Null if this is a + row-at-a-time object. Constant. + + We give a pointer into this to the user. + */ + png_byte * rowBuf; + /* The buffer in which we put the most recently read row. + Null if this is an all-at-once object. Constant. + + We give a pointer into this to the user. + */ + unsigned int nextRowNum; + /* The number of the next row to be read from this object. */ + +} Reader; + + + +static Reader * +reader_createAllAtOnce(struct pngx * const pngxP, + FILE * const ifP) { +/*---------------------------------------------------------------------------- + Create a Reader object that uses libpng's all-at-once raster reading + interface (libpng calls this the "high level" interface). + + The Reader object reads the PNG at construction time, stores the entire + raster, and hands it out as you call reader_read(). + + It is essential that *pngxP be already fully set up to read the image + (all options set). +-----------------------------------------------------------------------------*/ + Reader * readerP; + + MALLOCVAR_NOFAIL(readerP); + + readerP->pngxP = pngxP; + + allocPngRaster(pngxP, &readerP->pngRaster); + + readerP->rowBuf = NULL; + + pngx_readImage(pngxP, readerP->pngRaster); + + readerP->nextRowNum = 0; + + return readerP; +} + + + +static Reader * +reader_createRowByRow(struct pngx * const pngxP, + FILE * const ifP) { +/*---------------------------------------------------------------------------- + Create a Reader object that uses libpng's one-row-at-a-time raster reading + interface (libpng calls this the "low level" interface). + + The Reader object reads from the PNG file, via libpng, as its client + requests the rows. +-----------------------------------------------------------------------------*/ + Reader * readerP; + + MALLOCVAR_NOFAIL(readerP); + + readerP->pngxP = pngxP; + + readerP->pngRaster = NULL; + + MALLOCARRAY(readerP->rowBuf, computePngLineSize(pngxP)); + + if (!readerP->rowBuf) + pm_error("Could not allocate %u bytes for a PNG row buffer", + computePngLineSize(pngxP)); + + readerP->nextRowNum = 0; + + if (pngx_interlaceType(pngxP) != PNG_INTERLACE_NONE) + pm_message("WARNING: this is an interlaced PNG. The PAM output " + "will be interlaced. To get proper output, " + "don't use -byrow"); + + return readerP; +} + + + +static void +reader_destroy(Reader * const readerP) { + + if (readerP->pngRaster) + freePngRaster(readerP->pngRaster, readerP->pngxP); + + if (readerP->rowBuf) + free(readerP->rowBuf); + + free(readerP); +} + + + +static png_byte * +reader_read(Reader * const readerP) { +/*---------------------------------------------------------------------------- + Return a pointer to the next row of the raster. + + The pointer is into storage owned by this object. It is good until + the next read from the object, while the object exists. +-----------------------------------------------------------------------------*/ + png_byte * retval; + + if (readerP->pngRaster) { + if (readerP->nextRowNum >= pngx_imageHeight(readerP->pngxP)) + retval = NULL; + else + retval = readerP->pngRaster[readerP->nextRowNum]; + } else { + pngx_readRow(readerP->pngxP, readerP->rowBuf, NULL); + retval = readerP->rowBuf; + } + + ++readerP->nextRowNum; + + return retval; +} + + + static png_uint_16 -get_png_val(const png_byte ** const pp, - int const bit_depth) { +getPngVal(const png_byte ** const pp, + int const bitDepth) { png_uint_16 c; - if (bit_depth == 16) - c = (*((*pp)++)) << 8; + if (bitDepth == 16) + c = *(*pp)++ << 8; else c = 0; - c |= (*((*pp)++)); + c |= *(*pp)++; return c; } @@ -207,13 +474,14 @@ setTuple(const struct pam * const pamP, tuple const tuple, pngcolor const foreground, pngcolor const background, - enum alpha_handling const alphaHandling, + enum AlphaHandling const alphaHandling, + const struct pngx * const pngxP, png_uint_16 const alpha) { if (alphaHandling == ALPHA_ONLY) tuple[0] = alpha; else if (alphaHandling == ALPHA_NONE || - (alphaHandling == ALPHA_MIX && alpha == maxval)) { + (alphaHandling == ALPHA_MIX && alpha == pngxP->maxval)) { if (pamP->depth < 3) tuple[0] = foreground.r; else { @@ -236,227 +504,228 @@ setTuple(const struct pam * const pamP, if (pamP->depth < 3) tuple[0] = - alphaMix(foreground.r, background.r, alpha, maxval); + alphaMix(foreground.r, background.r, alpha, pngxP->maxval); else { tuple[PAM_RED_PLANE] = - alphaMix(foreground.r, background.r, alpha, maxval); + alphaMix(foreground.r, background.r, alpha, pngxP->maxval); tuple[PAM_GRN_PLANE] = - alphaMix(foreground.g, background.g, alpha, maxval); + alphaMix(foreground.g, background.g, alpha, pngxP->maxval); tuple[PAM_BLU_PLANE] = - alphaMix(foreground.b, background.b, alpha, maxval); + alphaMix(foreground.b, background.b, alpha, pngxP->maxval); } } } -static png_uint_16 -gamma_correct(png_uint_16 const v, - float const g) { +static bool +isColor(png_color const c) { - if (g != -1.0) - return (png_uint_16) ROUNDU(pow((double) v / maxval, (1.0 / g)) * - maxval); - else - return v; + return c.red != c.green || c.green != c.blue; } -static int iscolor (png_color c) -{ - return c.red != c.green || c.green != c.blue; -} +static void +saveText(struct pngx * const pngxP, + FILE * const tfP) { -static void save_text (png_info *info_ptr, FILE *tfp) -{ - int i, j, k; - - for (i = 0 ; i < info_ptr->num_text ; i++) { - 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 */ + struct pngx_text const text = pngx_text(pngxP); + + unsigned int i; + + for (i = 0 ; i < text.size; ++i) { + unsigned int j; + j = 0; + + while (text.line[i].key[j] != '\0' && + text.line[i].key[j] != ' ') + ++j; + + if (text.line[i].key[j] != ' ') { + fprintf(tfP, "%s", text.line[i].key); + for (j = strlen (text.line[i].key); j < 15; ++j) + putc(' ', tfP); + } else { + fprintf(tfP, "\"%s\"", text.line[i].key); + for (j = strlen (text.line[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') - for (k = 0 ; k < 16 ; k++) - putc ((int)' ', tfp); + for (j = 0; j < text.line[i].text_length; ++j) { + putc(text.line[i].text[j], tfP); + if (text.line[i].text[j] == '\n') { + unsigned int k; + for (k = 0; k < 16; ++k) + putc(' ', tfP); + } + } + putc('\n', tfP); } - putc ((int)'\n', tfp); - } } -static void show_time (png_info *info_ptr) -{ - static const char * const month[] = { - "", "January", "February", "March", "April", "May", "June", - "July", "August", "September", "October", "November", "December" - }; - - if (info_ptr->valid & PNG_INFO_tIME) { - if (info_ptr->mod_time.month < 1 || - 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", info_ptr->mod_time.month); - } else - pm_message ("modification time: %02d %s %d %02d:%02d:%02d", - info_ptr->mod_time.day, month[info_ptr->mod_time.month], - info_ptr->mod_time.year, info_ptr->mod_time.hour, - info_ptr->mod_time.minute, info_ptr->mod_time.second); - } -} -static void pngtopnm_error_handler (png_structp png_ptr, png_const_charp msg) -{ - jmpbuf_wrapper *jmpbuf_ptr; - /* 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. */ +static void +showTime(struct pngx * const pngxP) { - pm_message("fatal libpng error: %s", msg); + if (pngx_chunkIsPresent(pngxP, PNG_INFO_tIME)) { + png_time const modTime = pngx_time(pngxP); - jmpbuf_ptr = png_get_error_ptr(png_ptr); - if (jmpbuf_ptr == NULL) { - /* we are completely hosed now */ - pm_error("EXTREMELY fatal error: jmpbuf unrecoverable; terminating."); - } + static const char * const month[] = { + "", "January", "February", "March", "April", "May", "June", + "July", "August", "September", "October", "November", "December" + }; - longjmp(jmpbuf_ptr->jmpbuf, 1); + if (modTime.month < 1 || modTime.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", modTime.month); + } else { + pm_message("modification time: %02d %s %d %02d:%02d:%02d", + modTime.day, + month[modTime.month], + modTime.year, + modTime.hour, + modTime.minute, + modTime.second); + } + } } static void -dump_png_info(png_info *info_ptr) { +dumpTypeAndFilter(struct pngx * const pngxP) { - const char *type_string; - const char *filter_string; + const char * typeString; + const char * filterString; - switch (info_ptr->color_type) { - case PNG_COLOR_TYPE_GRAY: - type_string = "gray"; + switch (pngx_colorType(pngxP)) { + case PNG_COLOR_TYPE_GRAY: + typeString = "gray"; break; - - case PNG_COLOR_TYPE_GRAY_ALPHA: - type_string = "gray+alpha"; + + case PNG_COLOR_TYPE_GRAY_ALPHA: + typeString = "gray+alpha"; break; - - case PNG_COLOR_TYPE_PALETTE: - type_string = "palette"; + + case PNG_COLOR_TYPE_PALETTE: + typeString = "palette"; break; - case PNG_COLOR_TYPE_RGB: - type_string = "truecolor"; + case PNG_COLOR_TYPE_RGB: + typeString = "truecolor"; break; - case PNG_COLOR_TYPE_RGB_ALPHA: - type_string = "truecolor+alpha"; + case PNG_COLOR_TYPE_RGB_ALPHA: + typeString = "truecolor+alpha"; break; } - switch (info_ptr->filter_type) { + switch (pngx_filterType(pngxP)) { case PNG_FILTER_TYPE_BASE: - asprintfN(&filter_string, "base filter"); + pm_asprintf(&filterString, "base filter"); break; default: - asprintfN(&filter_string, "unknown filter type %d", - info_ptr->filter_type); + pm_asprintf(&filterString, "unknown filter type %d", + pngx_filterType(pngxP)); } - 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 ? + typeString, + pngx_interlaceType(pngxP) ? "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) + filterString); + + pm_strfree(filterString); +} + + + +static void +dumpPngInfo(struct pngx * const pngxP) { + + pm_message("reading a %u x %u image, %u bit%s", + pngx_imageWidth(pngxP), + pngx_imageHeight(pngxP), + pngx_bitDepth(pngxP), + pngx_bitDepth(pngxP) > 1 ? "s" : ""); + + dumpTypeAndFilter(pngxP); + + if (pngx_chunkIsPresent(pngxP, PNG_INFO_bKGD)) { + png_color_16 const background = pngx_bkgd(pngxP); + + pm_message("background {index, gray, red, green, blue} = " + "{%d, %d, %d, %d, %d}", + background.index, + background.gray, + background.red, + background.green, + background.blue); + } + + if (pngx_chunkIsPresent(pngxP, PNG_INFO_tRNS)) pm_message("tRNS chunk (transparency): %u entries", - info_ptr->num_trans); + pngx_trns(pngxP).numTrans); 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); + if (pngx_chunkIsPresent(pngxP, PNG_INFO_gAMA)) + pm_message("gAMA chunk (image gamma): gamma = %4.2f", + pngx_gama(pngxP)); else pm_message("gAMA chunk (image gamma): not present"); - - if (info_ptr->valid & PNG_INFO_sBIT) + + if (pngx_chunkIsPresent(pngxP, PNG_INFO_sBIT)) pm_message("sBIT chunk: present"); else pm_message("sBIT chunk: not present"); - if (info_ptr->valid & PNG_INFO_cHRM) + if (pngx_chunkIsPresent(pngxP, 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); + if (pngx_chunkIsPresent(pngxP, PNG_INFO_PLTE)) + pm_message("PLTE chunk: %d entries", pngx_plte(pngxP).size); else pm_message("PLTE chunk: not present"); - if (info_ptr->valid & PNG_INFO_bKGD) + if (pngx_chunkIsPresent(pngxP, PNG_INFO_bKGD)) pm_message("bKGD chunk: present"); else pm_message("bKGD chunk: not present"); - if (info_ptr->valid & PNG_INFO_hIST) + if (pngx_chunkIsPresent(pngxP, PNG_INFO_hIST)) pm_message("hIST chunk: present"); else pm_message("hIST chunk: not present"); - if (info_ptr->valid & PNG_INFO_pHYs) + if (pngx_chunkIsPresent(pngxP, PNG_INFO_pHYs)) pm_message("pHYs chunk: present"); else pm_message("pHYs chunk: not present"); - if (info_ptr->valid & PNG_INFO_oFFs) + if (pngx_chunkIsPresent(pngxP, PNG_INFO_oFFs)) pm_message("oFFs chunk: present"); else pm_message("oFFs chunk: not present"); - if (info_ptr->valid & PNG_INFO_tIME) + if (pngx_chunkIsPresent(pngxP, PNG_INFO_tIME)) pm_message("tIME chunk: present"); else pm_message("tIME chunk: not present"); - if (info_ptr->valid & PNG_INFO_pCAL) + if (pngx_chunkIsPresent(pngxP, PNG_INFO_pCAL)) pm_message("pCAL chunk: present"); else pm_message("pCAL chunk: not present"); - if (info_ptr->valid & PNG_INFO_sRGB) + if (pngx_chunkIsPresent(pngxP, PNG_INFO_sRGB)) pm_message("sRGB chunk: present"); else pm_message("sRGB chunk: not present"); @@ -464,83 +733,34 @@ dump_png_info(png_info *info_ptr) { -static unsigned int -computePngLineSize(png_info * const pngInfoP) { - - unsigned int const bytesPerSample = pngInfoP->bit_depth == 16 ? 2 : 1; - - unsigned int samplesPerPixel; - - switch (pngInfoP->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 < pngInfoP->width) - pm_error("Width %u of PNG is uncomputably large", - (unsigned int)pngInfoP->width); - - return pngInfoP->width * bytesPerSample * samplesPerPixel; -} - - - -static void -allocPngRaster(png_info * const pngInfoP, - png_byte *** const pngImageP) { - - unsigned int const lineSize = computePngLineSize(pngInfoP); - - png_byte ** pngImage; - unsigned int row; - - MALLOCARRAY(pngImage, pngInfoP->height); - - if (pngImage == NULL) - pm_error("couldn't allocate space for %u PNG raster rows", - (unsigned int)pngInfoP->height); - - for (row = 0; row < pngInfoP->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, - png_info * const pngInfoP) { - - unsigned int row; +static const png_color_16 +transColor(struct pngx * const pngxP) { - for (row = 0; row < pngInfoP->height; ++row) - free(pngRaster[row]); + struct pngx_trns const trans = pngx_trns(pngxP); - free(pngRaster); + assert(pngx_chunkIsPresent(pngxP, PNG_INFO_tRNS)); + + return trans.transColor; } static bool -isTransparentColor(pngcolor const color, - png_info * const pngInfoP, - double const totalgamma) { +isTransparentColor(pngcolor const color, + struct pngx * const pngxP, + GammaCorrection const gamma) { /*---------------------------------------------------------------------------- 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. + 'gamma' indicats what gamma correction has been applied to 'color' (we need + to know that because *pngxP identifies the color that is supposed to be + transparent in _not_ gamma-corrected form!). -----------------------------------------------------------------------------*/ bool retval; - if (pngInfoP->valid & PNG_INFO_tRNS) { - const png_color_16 * const transColorP = &pngInfoP->trans_values; + if (pngx_chunkIsPresent(pngxP, PNG_INFO_tRNS)) { + png_color_16 const transColor16 = transColor(pngxP); /* It seems odd that libpng lets you get gamma-corrected pixel values, but not gamma-corrected transparency or background @@ -556,15 +776,17 @@ isTransparentColor(pngcolor const color, pixels, and just do it ourselves. */ - switch (pngInfoP->color_type) { + switch (pngx_colorType(pngxP)) { case PNG_COLOR_TYPE_GRAY: - retval = color.r == gamma_correct(transColorP->gray, totalgamma); + retval = color.r == gammaCorrect(transColor16.gray, gamma, + pngxP->maxval); break; - default: - retval = - color.r == gamma_correct(transColorP->red, totalgamma) && - color.g == gamma_correct(transColorP->green, totalgamma) && - color.b == gamma_correct(transColorP->blue, totalgamma); + default: { + pngcolor const transColor = pngcolorFrom16(transColor16); + retval = pngColorEqual(color, + gammaCorrectColor(transColor, gamma, + pngxP->maxval)); + } } } else retval = FALSE; @@ -574,60 +796,63 @@ isTransparentColor(pngcolor const color, -#define SIG_CHECK_SIZE 4 - static void -read_sig_buf(FILE * const ifP) { - - unsigned char sig_buf[SIG_CHECK_SIZE]; - size_t bytesRead; - - bytesRead = fread(sig_buf, 1, SIG_CHECK_SIZE, ifP); - if (bytesRead != SIG_CHECK_SIZE) - pm_error ("input file is empty or too short"); +setupGammaCorrection(struct pngx * const pngxP, + bool const screenGammaIsKnown, + float const screenGamma, + GammaCorrection * const gammaCorrectionP) { +/*---------------------------------------------------------------------------- + Set up to have values from the PNG gamma-corrected. - if (png_sig_cmp(sig_buf, (png_size_t) 0, (png_size_t) SIG_CHECK_SIZE) - != 0) - pm_error ("input file is not a PNG file"); -} + Return as *gammaCorrectionP the correction necessary and tell the + libpng image reader *pngxP to do that same correction - on the pixels + only, as it can't do it on anything else (hence, Caller will have to + use *gammaCorrectionP to do it). + 'screenGammaIsKnown' means we know what the screen gamma is, and it is + 'screenGamma'. If we don't know what the screen gamma is, gamma + correction is not possible, so we set up for no gamma correction. + The gamma correction we ordain is a combination of the image gamma, + recorded in the PNG input and represented by *pngxP, and the screen gamma. -static void -setupGammaCorrection(png_struct * const png_ptr, - png_info * const info_ptr, - float const displaygamma, - float * const totalgammaP) { - - if (displaygamma == -1.0) - *totalgammaP = -1.0; + Note that "screen gamma" is a characteristic of both the display and the + viewing conditions. There are also "display gamma" and "viewing gamma," + respectively, but we don't care about the breakdown. In a dimly lit room, + viewing gamma is 1 and screen gamma is the same as the display gamma. +-----------------------------------------------------------------------------*/ + if (!screenGammaIsKnown) + gammaCorrectionP->needCorrection = false; else { float imageGamma; - if (info_ptr->valid & PNG_INFO_gAMA) - imageGamma = info_ptr->gamma; + if (pngx_chunkIsPresent(pngxP, PNG_INFO_gAMA)) + imageGamma = pngx_gama(pngxP); 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 (fabs(screenGamma * imageGamma - 1.0) < .01) { + gammaCorrectionP->needCorrection = false; if (verbose) pm_message("image gamma %4.2f matches " - "display gamma %4.2f. No conversion.", - imageGamma, displaygamma); + "screen gamma %4.2f. No conversion.", + imageGamma, screenGamma); } else { - png_set_gamma(png_ptr, displaygamma, imageGamma); - *totalgammaP = imageGamma * displaygamma; - /* in case of gamma-corrections, sBIT's as in the + pngx_setGamma(pngxP, screenGamma, imageGamma); + + gammaCorrectionP->needCorrection = true; + gammaCorrectionP->gamma = imageGamma * screenGamma; + /* In case of gamma-corrections, sBIT's as in the PNG-file are not valid anymore */ - info_ptr->valid &= ~PNG_INFO_sBIT; + pngx_removeChunk(pngxP, PNG_INFO_sBIT); if (verbose) pm_message("image gamma is %4.2f, " - "converted for display gamma of %4.2f", - imageGamma, displaygamma); + "display gamma is %4.2f; " + "combined gamma is %4.2f", + imageGamma, screenGamma, gammaCorrectionP->gamma); } } } @@ -635,20 +860,21 @@ setupGammaCorrection(png_struct * const png_ptr, static bool -paletteHasPartialTransparency(png_info * const info_ptr) { +paletteHasPartialTransparency(struct pngx * const pngxP) { bool retval; - if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE) { - if (info_ptr->valid & PNG_INFO_tRNS) { + if (pngx_colorType(pngxP) == PNG_COLOR_TYPE_PALETTE) { + if (pngx_chunkIsPresent(pngxP, PNG_INFO_tRNS)) { + struct pngx_trns const trans = pngx_trns(pngxP); + bool foundGray; unsigned int i; for (i = 0, foundGray = FALSE; - i < info_ptr->num_trans && !foundGray; + i < trans.numTrans && !foundGray; ++i) { - if (info_ptr->TRANS_ALPHA[i] != 0 && - info_ptr->TRANS_ALPHA[i] != maxval) { + if (trans.trans[i] != 0 && trans.trans[i] != pngxP->maxval) { foundGray = TRUE; } } @@ -664,61 +890,68 @@ paletteHasPartialTransparency(png_info * const info_ptr) { static void -getComponentSbitFg(png_info * const pngInfoP, - png_byte * const fgSbitP, - bool * const notUniformP) { - - if (pngInfoP->color_type == PNG_COLOR_TYPE_RGB || - pngInfoP->color_type == PNG_COLOR_TYPE_RGB_ALPHA || - pngInfoP->color_type == PNG_COLOR_TYPE_PALETTE) { - if (pngInfoP->sig_bit.red == pngInfoP->sig_bit.blue && - pngInfoP->sig_bit.red == pngInfoP->sig_bit.green) { +getComponentSbitFg(struct pngx * const pngxP, + png_byte * const fgSbitP, + bool * const notUniformP) { + + png_color_8 const sigBit = pngx_sbit(pngxP); + + assert(pngx_chunkIsPresent(pngxP, PNG_INFO_sBIT)); + + if (pngx_colorType(pngxP) == PNG_COLOR_TYPE_RGB || + pngx_colorType(pngxP) == PNG_COLOR_TYPE_RGB_ALPHA || + pngx_colorType(pngxP) == PNG_COLOR_TYPE_PALETTE) { + + if (sigBit.red == sigBit.blue && + sigBit.red == sigBit.green) { *notUniformP = false; - *fgSbitP = pngInfoP->sig_bit.red; + *fgSbitP = sigBit.red; } else *notUniformP = true; } else { /* It has only a gray channel so it's obviously uniform */ *notUniformP = false; - *fgSbitP = pngInfoP->sig_bit.gray; + *fgSbitP = sigBit.gray; } } static void -getComponentSbit(png_info * const pngInfoP, - enum alpha_handling const alphaHandling, +getComponentSbit(struct pngx * const pngxP, + enum AlphaHandling const alphaHandling, png_byte * const componentSbitP, bool * const notUniformP) { + assert(pngx_chunkIsPresent(pngxP, PNG_INFO_sBIT)); + switch (alphaHandling) { - case ALPHA_ONLY: + case ALPHA_ONLY: { /* We care only about the alpha channel, so the uniform Sbit is the alpha Sbit */ *notUniformP = false; - *componentSbitP = pngInfoP->sig_bit.alpha; - break; + *componentSbitP = pngx_sbit(pngxP).alpha; + } break; case ALPHA_NONE: case ALPHA_MIX: /* We aren't going to produce an alpha channel, so we care only about the uniformity of the foreground channels. */ - getComponentSbitFg(pngInfoP, componentSbitP, notUniformP); + getComponentSbitFg(pngxP, componentSbitP, notUniformP); break; case ALPHA_IN: { /* We care about both the foreground and the alpha */ bool fgNotUniform; png_byte fgSbit; - getComponentSbitFg(pngInfoP, &fgSbit, &fgNotUniform); + getComponentSbitFg(pngxP, &fgSbit, &fgNotUniform); if (fgNotUniform) *notUniformP = true; else { - if (fgSbit == pngInfoP->sig_bit.alpha) { + if (fgSbit == pngx_sbit(pngxP).alpha) { *notUniformP = false; *componentSbitP = fgSbit; } else @@ -731,8 +964,8 @@ getComponentSbit(png_info * const pngInfoP, static void -shiftPalette(png_info * const pngInfoP, - unsigned int const shift) { +shiftPalette(struct pngx * const pngxP, + unsigned int const shift) { /*---------------------------------------------------------------------------- Shift every component of every color in the PNG palette right by 'shift' bits because sBIT chunk says only those are significant. @@ -743,12 +976,14 @@ shiftPalette(png_info * const pngInfoP, "but sBIT chunk says %u bits", shift); else { + struct pngx_plte const palette = pngx_plte(pngxP); + unsigned int i; - for (i = 0; i < pngInfoP->num_palette; ++i) { - pngInfoP->palette[i].red >>= (8 - shift); - pngInfoP->palette[i].green >>= (8 - shift); - pngInfoP->palette[i].blue >>= (8 - shift); + for (i = 0; i < palette.size; ++i) { + palette.palette[i].red >>= (8 - shift); + palette.palette[i].green >>= (8 - shift); + palette.palette[i].blue >>= (8 - shift); } } } @@ -756,12 +991,11 @@ shiftPalette(png_info * const pngInfoP, static void -computeMaxvalFromSbit(png_struct * const pngP, - png_info * const pngInfoP, - enum alpha_handling const alphaHandling, +computeMaxvalFromSbit(struct pngx * const pngxP, + enum AlphaHandling const alphaHandling, png_uint_16 * const maxvalP, bool * const succeededP, - int * const errorlevelP) { + int * const errorLevelP) { /* sBIT handling is very tricky. If we are extracting only the image, we can use the sBIT info for grayscale and color images, @@ -782,37 +1016,38 @@ computeMaxvalFromSbit(png_struct * const pngP, Meaningless if they aren't all the same (i.e. 'notUniform') */ - getComponentSbit(pngInfoP, alphaHandling, &componentSigBit, ¬Uniform); + getComponentSbit(pngxP, alphaHandling, &componentSigBit, ¬Uniform); if (notUniform) { pm_message("This program cannot handle " "different bit depths for color channels"); - pm_message("writing file with %u bit resolution", pngInfoP->bit_depth); + pm_message("writing file with %u bit resolution", + pngx_bitDepth(pngxP)); *succeededP = false; - *errorlevelP = PNMTOPNG_WARNING_LEVEL; + *errorLevelP = PNMTOPNG_WARNING_LEVEL; } else if (componentSigBit > 15) { pm_message("Invalid PNG: says %u significant bits for a component; " "max possible is 16. Ignoring sBIT chunk.", componentSigBit); *succeededP = false; - *errorlevelP = PNMTOPNG_WARNING_LEVEL; + *errorLevelP = PNMTOPNG_WARNING_LEVEL; } else { if (alphaHandling == ALPHA_MIX && - (pngInfoP->color_type == PNG_COLOR_TYPE_RGB_ALPHA || - pngInfoP->color_type == PNG_COLOR_TYPE_GRAY_ALPHA || - paletteHasPartialTransparency(pngInfoP))) + (pngx_colorType(pngxP) == PNG_COLOR_TYPE_RGB_ALPHA || + pngx_colorType(pngxP) == PNG_COLOR_TYPE_GRAY_ALPHA || + paletteHasPartialTransparency(pngxP))) *succeededP = false; else { - if (componentSigBit < pngInfoP->bit_depth) { + if (componentSigBit < pngx_bitDepth(pngxP)) { pm_message("Image has fewer significant bits, " "writing file with %u bits", componentSigBit); *maxvalP = (1l << componentSigBit) - 1; *succeededP = true; - - if (pngInfoP->color_type == PNG_COLOR_TYPE_PALETTE) - shiftPalette(pngInfoP, componentSigBit); + + if (pngx_colorType(pngxP) == PNG_COLOR_TYPE_PALETTE) + shiftPalette(pngxP, componentSigBit); else - png_set_shift(pngP, &pngInfoP->sig_bit); + pngx_setShift(pngxP, pngx_sbit(pngxP)); } else *succeededP = false; } @@ -822,50 +1057,48 @@ computeMaxvalFromSbit(png_struct * const pngP, static void -setupSignificantBits(png_struct * const pngP, - png_info * const pngInfoP, - enum alpha_handling const alphaHandling, - png_uint_16 * const maxvalP, - int * const errorlevelP) { +setupSignificantBits(struct pngx * const pngxP, + enum AlphaHandling const alphaHandling, + int * const errorLevelP) { /*---------------------------------------------------------------------------- - Figure out what maxval would best express the information in the PNG - described by *pngP and *pngInfoP, with 'alpha' telling which - information in the PNG we care about (image or alpha mask). + Figure out what maxval is used in the PNG described by *pngxP, with 'alpha' + telling which information in the PNG we care about (image or alpha mask). + Update *pngxP with that information. Return the result as *maxvalP. - Also set up *pngP for the corresponding significant bits. + Also set up *pngxP for the corresponding significant bits. -----------------------------------------------------------------------------*/ bool gotItFromSbit; - if (pngInfoP->valid & PNG_INFO_sBIT) - computeMaxvalFromSbit(pngP, pngInfoP, alphaHandling, - maxvalP, &gotItFromSbit, errorlevelP); + if (pngx_chunkIsPresent(pngxP, PNG_INFO_sBIT)) + computeMaxvalFromSbit(pngxP, alphaHandling, + &pngxP->maxval, &gotItFromSbit, errorLevelP); else gotItFromSbit = false; if (!gotItFromSbit) { - if (pngInfoP->color_type == PNG_COLOR_TYPE_PALETTE) { + if (pngx_colorType(pngxP) == PNG_COLOR_TYPE_PALETTE) { if (alphaHandling == ALPHA_ONLY) { - if (pngInfoP->color_type == PNG_COLOR_TYPE_GRAY || - pngInfoP->color_type == PNG_COLOR_TYPE_RGB) + if (pngx_colorType(pngxP) == PNG_COLOR_TYPE_GRAY || + pngx_colorType(pngxP) == PNG_COLOR_TYPE_RGB) /* The alpha mask will be all opaque, so maxval 1 is plenty */ - *maxvalP = 1; - else if (paletteHasPartialTransparency(pngInfoP)) + pngxP->maxval = 1; + else if (paletteHasPartialTransparency(pngxP)) /* Use same maxval as PNG transparency palette for simplicity */ - *maxvalP = 255; + pngxP->maxval = 255; else /* A common case, so we conserve bits */ - *maxvalP = 1; + pngxP->maxval = 1; } else /* Use same maxval as PNG palette for simplicity */ - *maxvalP = 255; + pngxP->maxval = 255; } else { - *maxvalP = (1l << pngInfoP->bit_depth) - 1; + pngxP->maxval = (1l << pngx_bitDepth(pngxP)) - 1; } } } @@ -873,22 +1106,24 @@ setupSignificantBits(png_struct * const pngP, static bool -imageHasColor(png_info * const info_ptr) { +imageHasColor(struct pngx * const pngxP) { bool retval; - if (info_ptr->color_type == PNG_COLOR_TYPE_GRAY || - info_ptr->color_type == PNG_COLOR_TYPE_GRAY_ALPHA) + if (pngx_colorType(pngxP) == PNG_COLOR_TYPE_GRAY || + pngx_colorType(pngxP) == PNG_COLOR_TYPE_GRAY_ALPHA) retval = FALSE; - else if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE) { + else if (pngx_colorType(pngxP) == PNG_COLOR_TYPE_PALETTE) { + struct pngx_plte const palette = pngx_plte(pngxP); + bool foundColor; unsigned int i; for (i = 0, foundColor = FALSE; - i < info_ptr->num_palette && !foundColor; + i < palette.size && !foundColor; ++i) { - if (iscolor(info_ptr->palette[i])) + if (isColor(palette.palette[i])) foundColor = TRUE; } retval = foundColor; @@ -901,8 +1136,8 @@ imageHasColor(png_info * const info_ptr) { static void -determineOutputType(png_info * const pngInfoP, - enum alpha_handling const alphaHandling, +determineOutputType(struct pngx * const pngxP, + enum AlphaHandling const alphaHandling, pngcolor const bgColor, xelval const maxval, int * const formatP, @@ -916,7 +1151,7 @@ determineOutputType(png_info * const pngInfoP, } else { /* The output is a normal Netpbm image */ bool const outputIsColor = - imageHasColor(pngInfoP) || !isGrayscale(bgColor); + imageHasColor(pngxP) || !isGrayscale(bgColor); if (alphaHandling == ALPHA_IN) { *formatP = PAM_FORMAT; @@ -942,11 +1177,11 @@ determineOutputType(png_info * const pngInfoP, static void -getBackgroundColor(png_info * const info_ptr, - const char * const requestedColor, - float const totalgamma, - xelval const maxval, - pngcolor * const bgColorP) { +getBackgroundColor(struct pngx * const pngxP, + const char * const requestedColor, + GammaCorrection const gamma, + 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. @@ -964,31 +1199,31 @@ getBackgroundColor(png_info * const info_ptr, bgColorP->g = PPM_GETG(backcolor); bgColorP->b = PPM_GETB(backcolor); - } else if (info_ptr->valid & PNG_INFO_bKGD) { - /* didn't manage to get libpng to work (bugs?) concerning background + } else if (pngx_chunkIsPresent(pngxP, PNG_INFO_bKGD)) { + /* Didn't manage to get libpng to work (bugs?) concerning background processing, therefore we do our own. */ - switch (info_ptr->color_type) { + png_color_16 const background = pngx_bkgd(pngxP); + switch (pngx_colorType(pngxP)) { case PNG_COLOR_TYPE_GRAY: case PNG_COLOR_TYPE_GRAY_ALPHA: bgColorP->r = bgColorP->g = bgColorP->b = - gamma_correct(info_ptr->background.gray, totalgamma); + gammaCorrect(background.gray, gamma, pngxP->maxval); break; case PNG_COLOR_TYPE_PALETTE: { + struct pngx_plte const palette = pngx_plte(pngxP); png_color const rawBgcolor = - info_ptr->palette[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); + palette.palette[background.index]; + *bgColorP = gammaCorrectColor(pngcolorFromByte(rawBgcolor), + gamma, pngxP->maxval); } break; case PNG_COLOR_TYPE_RGB: case PNG_COLOR_TYPE_RGB_ALPHA: { - png_color_16 const rawBgcolor = info_ptr->background; + png_color_16 const rawBgcolor = background; - bgColorP->r = gamma_correct(rawBgcolor.red, totalgamma); - bgColorP->g = gamma_correct(rawBgcolor.green, totalgamma); - bgColorP->b = gamma_correct(rawBgcolor.blue, totalgamma); + *bgColorP = gammaCorrectColor(pngcolorFrom16(rawBgcolor), + gamma, pngxP->maxval); } break; } @@ -999,31 +1234,88 @@ getBackgroundColor(png_info * const info_ptr, -#define GET_PNG_VAL(p) get_png_val(&(p), pngInfoP->bit_depth) +static void +warnNonsquarePixels(struct pngx * const pngxP, + int * const errorLevelP) { + + if (pngx_pixelAspectRatioIsKnown(pngxP)) { + float const r = pngx_pixelAspectRatio(pngxP); + + if (r != 1.0) { + const char * const baseMsg = "warning - non-square pixels"; + + if (pm_have_float_format()) + pm_message("%s; to fix do a 'pamscale -%cscale %g'", + baseMsg, + r < 1.0 ? 'x' : 'y', + r < 1.0 ? 1.0 / r : r); + else + pm_message("%s", baseMsg); + + *errorLevelP = PNMTOPNG_WARNING_LEVEL; + } + } +} + + + +static png_uint_16 +paletteAlpha(struct pngx * const pngxP, + png_uint_16 const index, + sample const maxval) { + + png_uint_16 retval; + + if (pngx_chunkIsPresent(pngxP, PNG_INFO_tRNS)) { + struct pngx_trns const trans = pngx_trns(pngxP); + + if (index < trans.numTrans) + retval = trans.trans[index]; + else + retval = maxval; + } else + retval = maxval; + + return retval; +} + + + +#define GET_PNG_VAL(p) getPngVal(&(p), pngx_bitDepth(pngxP)) static void makeTupleRow(const struct pam * const pamP, const tuple * const tuplerow, - png_info * const pngInfoP, + struct pngx * const pngxP, const png_byte * const pngRasterRow, pngcolor const bgColor, - enum alpha_handling const alphaHandling, - double const totalgamma) { - + enum AlphaHandling const alphaHandling, + GammaCorrection const gamma) { +/*---------------------------------------------------------------------------- + Convert a raster row as supplied by libpng, at 'pngRasterRow' and + described by *pngxP, to a libpam-style tuple row at 'tupleRow'. + + Where the raster says the pixel isn't opaque, we either include that + opacity information in the output pixel or we mix the pixel with background + color 'bgColor', as directed by 'alphaHandling'. Or, if 'alphaHandling' + says so, we may produce an output row of _only_ the transparency + information. +-----------------------------------------------------------------------------*/ const png_byte * pngPixelP; unsigned int col; pngPixelP = &pngRasterRow[0]; /* initial value */ - for (col = 0; col < pngInfoP->width; ++col) { - switch (pngInfoP->color_type) { + for (col = 0; col < pngx_imageWidth(pngxP); ++col) { + switch (pngx_colorType(pngxP)) { case PNG_COLOR_TYPE_GRAY: { pngcolor fgColor; fgColor.r = fgColor.g = fgColor.b = GET_PNG_VAL(pngPixelP); setTuple(pamP, tuplerow[col], fgColor, bgColor, alphaHandling, - isTransparentColor(fgColor, pngInfoP, totalgamma) ? - 0 : maxval); + pngxP, + isTransparentColor(fgColor, pngxP, gamma) ? + 0 : pngxP->maxval); } break; @@ -1034,13 +1326,14 @@ makeTupleRow(const struct pam * const pamP, fgColor.r = fgColor.g = fgColor.b = GET_PNG_VAL(pngPixelP); alpha = GET_PNG_VAL(pngPixelP); setTuple(pamP, tuplerow[col], fgColor, bgColor, - alphaHandling, alpha); + alphaHandling, pngxP, alpha); } break; case PNG_COLOR_TYPE_PALETTE: { - png_uint_16 const index = GET_PNG_VAL(pngPixelP); - png_color const paletteColor = pngInfoP->palette[index]; + png_uint_16 const index = GET_PNG_VAL(pngPixelP); + struct pngx_plte const palette = pngx_plte(pngxP); + png_color const paletteColor = palette.palette[index]; pngcolor fgColor; @@ -1049,9 +1342,7 @@ makeTupleRow(const struct pam * const pamP, fgColor.b = paletteColor.blue; setTuple(pamP, tuplerow[col], fgColor, bgColor, alphaHandling, - (pngInfoP->valid & PNG_INFO_tRNS) && - index < pngInfoP->num_trans ? - pngInfoP->TRANS_ALPHA[index] : maxval); + pngxP, paletteAlpha(pngxP, index, pngxP->maxval)); } break; @@ -1062,8 +1353,9 @@ makeTupleRow(const struct pam * const pamP, fgColor.g = GET_PNG_VAL(pngPixelP); fgColor.b = GET_PNG_VAL(pngPixelP); setTuple(pamP, tuplerow[col], fgColor, bgColor, alphaHandling, - isTransparentColor(fgColor, pngInfoP, totalgamma) ? - 0 : maxval); + pngxP, + isTransparentColor(fgColor, pngxP, gamma) ? + 0 : pngxP->maxval); } break; @@ -1076,12 +1368,13 @@ makeTupleRow(const struct pam * const pamP, fgColor.b = GET_PNG_VAL(pngPixelP); alpha = GET_PNG_VAL(pngPixelP); setTuple(pamP, tuplerow[col], fgColor, bgColor, - alphaHandling, alpha); + alphaHandling, pngxP, alpha); } break; default: - pm_error("unknown PNG color type: %d", pngInfoP->color_type); + pm_error("unknown PNG color type: %d", + pngx_colorType(pngxP)); } } } @@ -1103,8 +1396,8 @@ reportOutputFormat(const struct pam * const pamP) { pm_message("Writing a PPM file with maxval %lu", pamP->maxval); break; case PAM_FORMAT: - pm_message("Writing a PAM file with tuple type %s, maxval %u", - pamP->tuple_type, maxval); + pm_message("Writing a PAM file with tuple type %s, maxval %lu", + pamP->tuple_type, pamP->maxval); break; default: assert(false); /* Every possible value handled above */ @@ -1115,15 +1408,15 @@ reportOutputFormat(const struct pam * const pamP) { static void writeNetpbm(struct pam * const pamP, - png_info * const pngInfoP, - png_byte ** const pngRaster, + struct pngx * const pngxP, + Reader * const rasterReaderP, pngcolor const bgColor, - enum alpha_handling const alphaHandling, - double const totalgamma) { + enum AlphaHandling const alphaHandling, + GammaCorrection const gamma) { /*---------------------------------------------------------------------------- Write a Netpbm image of either the image or the alpha mask, according to - 'alphaHandling' that is in the PNG image described by 'pngInfoP' and - pngRaster. + 'alphaHandling' that is in the PNG image described by *pngxP, reading + its raster with the raster reader object *rasterReaderP. *pamP describes the required output image and is consistent with *pngInfoP. @@ -1141,9 +1434,13 @@ writeNetpbm(struct pam * const pamP, tuplerow = pnm_allocpamrow(pamP); - for (row = 0; row < pngInfoP->height; ++row) { - makeTupleRow(pamP, tuplerow, pngInfoP, pngRaster[row], bgColor, - alphaHandling, totalgamma); + for (row = 0; row < pngx_imageHeight(pngxP); ++row) { + png_byte * const pngRow = reader_read(rasterReaderP); + + assert(pngRow); + + makeTupleRow(pamP, tuplerow, pngxP, pngRow, bgColor, + alphaHandling, gamma); pnm_writepamrow(pamP, tuplerow); } @@ -1153,97 +1450,68 @@ writeNetpbm(struct pam * const pamP, static void -convertpng(FILE * const ifp, - FILE * const tfp, - struct cmdlineInfo const cmdline, - int * const errorlevelP) { - - png_struct * png_ptr; - png_info * info_ptr; - png_byte ** png_image; +convertpng(FILE * const ifP, + FILE * const tfP, + struct CmdlineInfo const cmdline, + int * const errorLevelP) { + + Reader * rasterReaderP; pngcolor bgColor; - float totalgamma; + GammaCorrection gamma; struct pam pam; + jmp_buf jmpbuf; + struct pngx * pngxP; - *errorlevelP = 0; - - read_sig_buf(ifp); - - png_ptr = png_create_read_struct( - PNG_LIBPNG_VER_STRING, - &pngtopnm_jmpbuf_struct, pngtopnm_error_handler, NULL); - if (png_ptr == NULL) - pm_error("cannot allocate main libpng structure (png_ptr)"); + *errorLevelP = 0; - info_ptr = png_create_info_struct (png_ptr); - if (info_ptr == NULL) - pm_error("cannot allocate LIBPNG structures"); - - if (setjmp(pngtopnm_jmpbuf_struct.jmpbuf)) + if (setjmp(jmpbuf)) pm_error ("setjmp returns error condition"); - png_init_io (png_ptr, ifp); - png_set_sig_bytes (png_ptr, SIG_CHECK_SIZE); - png_read_info (png_ptr, info_ptr); - - allocPngRaster(info_ptr, &png_image); + pngx_create(&pngxP, PNGX_READ, &jmpbuf); - if (info_ptr->bit_depth < 8) - png_set_packing (png_ptr); - - setupGammaCorrection(png_ptr, info_ptr, cmdline.gamma, &totalgamma); - - setupSignificantBits(png_ptr, info_ptr, cmdline.alpha, - &maxval, errorlevelP); - - getBackgroundColor(info_ptr, cmdline.background, totalgamma, maxval, - &bgColor); - - png_read_image(png_ptr, png_image); - png_read_end(png_ptr, info_ptr); + pngx_readStart(pngxP, ifP); if (verbose) - /* 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. - */ - dump_png_info(info_ptr); + dumpPngInfo(pngxP); if (cmdline.time) - show_time(info_ptr); - if (tfp) - save_text(info_ptr, tfp); + showTime(pngxP); + if (tfP) + saveText(pngxP, tfP); - if (info_ptr->valid & PNG_INFO_pHYs) { - float const r = - (float)info_ptr->x_pixels_per_unit / 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; - } - } + warnNonsquarePixels(pngxP, errorLevelP); + setupGammaCorrection(pngxP, cmdline.gammaSpec, cmdline.gamma, &gamma); + + setupSignificantBits(pngxP, cmdline.alpha, errorLevelP); + + getBackgroundColor(pngxP, cmdline.background, gamma, pngxP->maxval, + &bgColor); + pam.size = sizeof(pam); pam.len = PAM_STRUCT_SIZE(tuple_type); pam.file = stdout; pam.plainformat = 0; - pam.height = info_ptr->height; - pam.width = info_ptr->width; - pam.maxval = maxval; + pam.height = pngx_imageHeight(pngxP); + pam.width = pngx_imageWidth(pngxP); + pam.maxval = pngxP->maxval; - determineOutputType(info_ptr, cmdline.alpha, bgColor, maxval, + determineOutputType(pngxP, cmdline.alpha, bgColor, pngxP->maxval, &pam.format, &pam.depth, pam.tuple_type); - writeNetpbm(&pam, info_ptr, png_image, bgColor, cmdline.alpha, totalgamma); + rasterReaderP = cmdline.byrow ? + reader_createRowByRow(pngxP, ifP) : reader_createAllAtOnce(pngxP, ifP); - fflush(stdout); + writeNetpbm(&pam, pngxP, rasterReaderP, bgColor, + cmdline.alpha, gamma); + + reader_destroy(rasterReaderP); - freePngRaster(png_image, info_ptr); + pngx_readEnd(pngxP); - png_destroy_read_struct(&png_ptr, &info_ptr, NULL); + fflush(stdout); + + pngx_destroy(pngxP); } @@ -1251,10 +1519,10 @@ convertpng(FILE * const ifp, int main(int argc, const char *argv[]) { - struct cmdlineInfo cmdline; + struct CmdlineInfo cmdline; FILE * ifP; FILE * tfP; - int errorlevel; + int errorLevel; pm_proginit(&argc, argv); @@ -1262,14 +1530,14 @@ main(int argc, const char *argv[]) { verbose = cmdline.verbose; - ifP = pm_openr(cmdline.inputFilespec); + ifP = pm_openr(cmdline.inputFileName); if (cmdline.text) tfP = pm_openw(cmdline.text); else tfP = NULL; - convertpng(ifP, tfP, cmdline, &errorlevel); + convertpng(ifP, tfP, cmdline, &errorLevel); if (tfP) pm_close(tfP); @@ -1277,5 +1545,8 @@ main(int argc, const char *argv[]) { pm_close(ifP); pm_close(stdout); - return errorlevel; + return errorLevel; } + + + |