/****************************************************************************** pnmremap.c ******************************************************************************* Replace colors in an input image with colors from a given colormap image. For PGM input, do the equivalent. By Bryan Henderson, San Jose, CA 2001.12.17 Derived from ppmquant, originally by Jef Poskanzer. Copyright (C) 1989, 1991 by Jef Poskanzer. Copyright (C) 2001 by Bryan Henderson. 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. ******************************************************************************/ #include #include #include #include "pm_c_util.h" #include "mallocvar.h" #include "nstring.h" #include "rand.h" #include "shhopt.h" #include "pam.h" #include "ppm.h" #include "pammap.h" #define MAXCOLORS 32767u enum MissingMethod { MISSING_FIRST, MISSING_SPECIFIED, MISSING_CLOSE }; enum InitRandom { RANDOM_NONE, RANDOM_WITHSEED, RANDOM_NOSEED }; struct Random { enum InitRandom init; unsigned int seed; }; struct CmdlineInfo { /* All the information the user supplied in the command line, in a form easy for the program to use. */ const char * inputFilespec; /* Filespec of input file */ const char * mapFilespec; /* Filespec of colormap file */ unsigned int floyd; /* Boolean: -floyd/-fs option */ struct Random random; enum MissingMethod missingMethod; char * missingcolor; /* -missingcolor value. Null if not specified */ unsigned int verbose; }; static void parseCommandLine (int argc, const char ** argv, struct CmdlineInfo * const 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 pm_optParseOptions3 on how to parse our options. */ optStruct3 opt; unsigned int option_def_index; unsigned int nofloyd, firstisdefault; unsigned int missingSpec, mapfileSpec, norandomSpec, randomseedSpec; MALLOCARRAY_NOFAIL(option_def, 100); option_def_index = 0; /* incremented by OPTENT3 */ OPTENT3(0, "floyd", OPT_FLAG, NULL, &cmdlineP->floyd, 0); OPTENT3(0, "fs", OPT_FLAG, NULL, &cmdlineP->floyd, 0); OPTENT3(0, "nofloyd", OPT_FLAG, NULL, &nofloyd, 0); OPTENT3(0, "nofs", OPT_FLAG, NULL, &nofloyd, 0); OPTENT3(0, "norandom", OPT_FLAG, NULL, &norandomSpec, 0); OPTENT3(0, "randomseed", OPT_UINT, &cmdlineP->random.seed, &randomseedSpec, 0); OPTENT3(0, "firstisdefault", OPT_FLAG, NULL, &firstisdefault, 0); OPTENT3(0, "mapfile", OPT_STRING, &cmdlineP->mapFilespec, &mapfileSpec, 0); OPTENT3(0, "missingcolor", OPT_STRING, &cmdlineP->missingcolor, &missingSpec, 0); OPTENT3(0, "verbose", OPT_FLAG, NULL, &cmdlineP->verbose, 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 */ cmdlineP->missingcolor = NULL; /* default value */ pm_optParseOptions3(&argc, (char **)argv, opt, sizeof(opt), 0); /* Uses and sets argc, argv, and some of *cmdline_p and others. */ if (cmdlineP->floyd && nofloyd) pm_error("You cannot specify both -floyd and -nofloyd options."); if (cmdlineP->floyd) { if (norandomSpec) { if (randomseedSpec) pm_error("You cannot specify both -norandom and -randomseed."); else cmdlineP->random.init = RANDOM_NONE; } else { if (randomseedSpec) cmdlineP->random.init = RANDOM_WITHSEED; else cmdlineP->random.init = RANDOM_NOSEED; } } else { if (norandomSpec) pm_message("-floyd not specified. -norandom has no effect."); if (randomseedSpec) pm_message("-floyd not specified. Ignoring -randomseed value."); } if (firstisdefault && missingSpec) pm_error("You cannot specify both -missing and -firstisdefault."); if (firstisdefault) cmdlineP->missingMethod = MISSING_FIRST; else if (missingSpec) cmdlineP->missingMethod = MISSING_SPECIFIED; else cmdlineP->missingMethod = MISSING_CLOSE; if (!mapfileSpec) pm_error("You must specify the -mapfile option."); if (argc-1 > 1) pm_error("Program takes at most one argument: the input file " "specification. " "You specified %d arguments.", argc-1); if (argc-1 < 1) cmdlineP->inputFilespec = "-"; else cmdlineP->inputFilespec = argv[1]; free(option_def); } typedef enum { ADJUST_NONE, ADJUST_RGBTO1, ADJUST_GRAYSCALETO3 } depthAdjustment; static void rgbToDepth1(tuple const tuple) { unsigned int plane; double grayvalue; grayvalue = 0.0; /* initial value */ for (plane = 0; plane < 3; ++plane) grayvalue += pnm_lumin_factor[plane] * tuple[plane]; tuple[0] = (sample) (grayvalue + 0.5); } static void grayscaleToDepth3(tuple const tuple) { tuple[1] = tuple[0]; tuple[2] = tuple[0]; } static void adjustDepthTuple(tuple const tuple, depthAdjustment const adjustment) { switch (adjustment) { case ADJUST_NONE: break; case ADJUST_RGBTO1: rgbToDepth1(tuple); break; case ADJUST_GRAYSCALETO3: grayscaleToDepth3(tuple); break; } } static void inverseAdjustDepthTuple(tuple const tuple, depthAdjustment const adjustment) { switch (adjustment) { case ADJUST_NONE: break; case ADJUST_RGBTO1: grayscaleToDepth3(tuple); break; case ADJUST_GRAYSCALETO3: rgbToDepth1(tuple); break; } } static void adjustDepthRow(tuple * const tupleRow, unsigned int const width, depthAdjustment const adjustment) { /*---------------------------------------------------------------------------- Change tupleRow[] depth as indicated by 'adjustment', i.e. turned from RGB to grayscale or grayscale to RGB. We assume tupleRow[] is consistent with 'adjustment' -- i.e. if 'adjustment' says grayscale to RGB, tupleRow[] has an allocation depth of at least 3 and if 'adjustment' says from RGB to grayscale, tupleRow[] has RGB tuples. -----------------------------------------------------------------------------*/ if (adjustment == ADJUST_NONE) { } else { unsigned int col; for (col = 0; col < width; ++col) { if (adjustment == ADJUST_RGBTO1) rgbToDepth1(tupleRow[col]); else { assert(adjustment == ADJUST_GRAYSCALETO3); grayscaleToDepth3(tupleRow[col]); } } } } static void selectDepthAdjustment(const struct pam * const pamP, unsigned int const newDepth, depthAdjustment * const adjustmentP) { /*---------------------------------------------------------------------------- Determine what kind of depth adjustment the pixels of an image described by 'pamP' need to be comparable to pixels with depth 'newDepth'. The only depth changes we know how to do are: - from tuple type RGB, depth 3 to depth 1 We change it to grayscale or black and white. For this, we return *adjustmentP == ADJUST_RGBTO1. - from tuple type GRAYSCALE or BLACKANDWHITE depth 1 to depth 3. We change it to RGB. For this, we return *adjustmentP == ADJUST_GRAYSCALETO3. For any other depth change request, we issue an error message and abort the program. If 'newDepth' is the same depth as the original (no depth change required), we return *adjustmentP == ADJUST_NONE. -----------------------------------------------------------------------------*/ if (newDepth == pamP->depth) *adjustmentP = ADJUST_NONE; else { if (pm_stripeq(pamP->tuple_type, "RGB")) { if (newDepth != 1) { pm_error("Map image depth of %u differs from input image " "depth of %u, and the tuple type is RGB. " "The only depth to which I know how to convert " "an RGB tuple is 1.", newDepth, pamP->depth); } else *adjustmentP = ADJUST_RGBTO1; } else if (pm_stripeq(pamP->tuple_type, "GRAYSCALE") || pm_stripeq(pamP->tuple_type, "BLACKANDWHITE")) { if (newDepth != 3) { pm_error("Map image depth of %u differs from input image " "depth of %u, and the tuple type is GRAYSCALE " "or BLACKANDWHITE. " "The only depth to which I know how to convert " "a GRAYSCALE or BLACKANDWHITE tuple is 3.", newDepth, pamP->depth); } else *adjustmentP = ADJUST_GRAYSCALETO3; } else { pm_error("Map image depth of %u differs from input image depth " "of %u, and the input image does not have a tuple type " "that I know how to convert to the map depth. " "I can convert RGB, GRAYSCALE, and BLACKANDWHITE. " "The input image is '%.*s'.", newDepth, pamP->depth, (int)sizeof(pamP->tuple_type), pamP->tuple_type); } } } static void computeColorMapFromMap(struct pam * const mappamP, tuple ** const maptuples, tupletable * const colormapP, unsigned int * const newcolorsP) { /*---------------------------------------------------------------------------- Produce a colormap containing the colors that we will use in the output. Make it include exactly those colors that are in the image described by *mappamP and maptuples[][]. Return the number of colors in the returned colormap as *newcolorsP. -----------------------------------------------------------------------------*/ unsigned int colors; if (mappamP->width == 0 || mappamP->height == 0) pm_error("colormap file contains no pixels"); *colormapP = pnm_computetuplefreqtable(mappamP, maptuples, MAXCOLORS, &colors); if (*colormapP == NULL) pm_error("too many colors in colormap!"); pm_message("%u colors found in colormap", colors); *newcolorsP = colors; } #define FS_SCALE 1024 struct Fserr { unsigned int width; /* Width of the image being dithered */ long ** thiserr; long ** nexterr; bool fsForward; /* We are in a left-to-right row */ int begCol; /* First column in the sweep. Determined by 'fsForward': either the leftmost or rightmost column in the row */ int endCol; /* Column after the last column in the sweep. Determined by 'fsForward': either one past the left end or one past the right end of the row. */ int step; /* What we add to a column number to get the next one in the sweep. Determined by 'fsForward': +1 or -1. */ }; static void randomizeError(long ** const err, unsigned int const width, unsigned int const depth, struct Random const random) { /*---------------------------------------------------------------------------- Set a random error in the range [-1 .. 1] (normalized via FS_SCALE) in the error array err[][]. -----------------------------------------------------------------------------*/ unsigned int col; struct pm_randSt randSt; assert(random.init != RANDOM_NONE); pm_randinit(&randSt); pm_srand2(&randSt, random.init == RANDOM_WITHSEED, random.seed); for (col = 0; col < width; ++col) { unsigned int plane; for (plane = 0; plane < depth; ++plane) err[plane][col] = pm_rand(&randSt) % (FS_SCALE * 2) - FS_SCALE; } pm_randterm(&randSt); } static void zeroError(long ** const err, unsigned int const width, unsigned int const depth) { /*---------------------------------------------------------------------------- Set all errors to zero in the error array err[][]. -----------------------------------------------------------------------------*/ unsigned int col; for (col = 0; col < width; ++col) { unsigned int plane; for (plane = 0; plane < depth; ++plane) err[plane][col] = 0; } } static void fserr_setForward(struct Fserr * const fserrP) { fserrP->fsForward = TRUE; fserrP->begCol = 0; fserrP->endCol = fserrP->width; fserrP->step = +1; } static void fserr_setBackward(struct Fserr * const fserrP) { fserrP->fsForward = FALSE; fserrP->begCol = fserrP->width - 1; fserrP->endCol = -1; fserrP->step = -1; } static void fserr_init(struct pam * const pamP, struct Fserr * const fserrP, struct Random const random) { /*---------------------------------------------------------------------------- Initialize the Floyd-Steinberg error vectors -----------------------------------------------------------------------------*/ unsigned int plane; unsigned int const fserrSz = pamP->width + 2; fserrP->width = pamP->width; MALLOCARRAY(fserrP->thiserr, pamP->depth); if (fserrP->thiserr == NULL) pm_error("Out of memory allocating Floyd-Steinberg structures " "for depth %u", pamP->depth); MALLOCARRAY(fserrP->nexterr, pamP->depth); if (fserrP->nexterr == NULL) pm_error("Out of memory allocating Floyd-Steinberg structures " "for depth %u", pamP->depth); for (plane = 0; plane < pamP->depth; ++plane) { MALLOCARRAY(fserrP->thiserr[plane], fserrSz); if (fserrP->thiserr[plane] == NULL) pm_error("Out of memory allocating Floyd-Steinberg structures " "for Plane %u, size %u", plane, fserrSz); MALLOCARRAY(fserrP->nexterr[plane], fserrSz); if (fserrP->nexterr[plane] == NULL) pm_error("Out of memory allocating Floyd-Steinberg structures " "for Plane %u, size %u", plane, fserrSz); } if (random.init != RANDOM_NONE) randomizeError(fserrP->thiserr, fserrSz, pamP->depth, random); else zeroError(fserrP->thiserr, fserrSz, pamP->depth); fserr_setForward(fserrP); } static void floydInitRow(struct pam * const pamP, struct Fserr * const fserrP) { unsigned int col; for (col = 0; col < pamP->width + 2; ++col) { unsigned int plane; for (plane = 0; plane < pamP->depth; ++plane) fserrP->nexterr[plane][col] = 0; } } static void floydAdjustColor(struct pam * const pamP, tuple const intuple, tuple const outtuple, struct Fserr * const fserrP, int const col) { /*---------------------------------------------------------------------------- Use Floyd-Steinberg errors to adjust actual color. -----------------------------------------------------------------------------*/ unsigned int plane; for (plane = 0; plane < pamP->depth; ++plane) { long int const s = intuple[plane] + fserrP->thiserr[plane][col+1] / FS_SCALE; outtuple[plane] = MIN(pamP->maxval, MAX(0,s)); } } static void floydPropagateErr(struct pam * const pamP, struct Fserr * const fserrP, int const col, tuple const oldtuple, tuple const newtuple) { /*---------------------------------------------------------------------------- Propagate Floyd-Steinberg error terms. The error is due to substituting the tuple value 'newtuple' for the tuple value 'oldtuple' (both described by *pamP). The error terms are meant to be used to introduce a compensating error into the future selection of tuples nearby in the image. -----------------------------------------------------------------------------*/ unsigned int plane; for (plane = 0; plane < pamP->depth; ++plane) { long const newSample = newtuple[plane]; long const oldSample = oldtuple[plane]; long const err = (oldSample - newSample) * FS_SCALE; if (fserrP->fsForward) { fserrP->thiserr[plane][col + 2] += ( err * 7 ) / 16; fserrP->nexterr[plane][col ] += ( err * 3 ) / 16; fserrP->nexterr[plane][col + 1] += ( err * 5 ) / 16; fserrP->nexterr[plane][col + 2] += ( err ) / 16; } else { fserrP->thiserr[plane][col ] += ( err * 7 ) / 16; fserrP->nexterr[plane][col + 2] += ( err * 3 ) / 16; fserrP->nexterr[plane][col + 1] += ( err * 5 ) / 16; fserrP->nexterr[plane][col ] += ( err ) / 16; } } } static void floydSwitchDir(struct pam * const pamP, struct Fserr * const fserrP) { unsigned int plane; for (plane = 0; plane < pamP->depth; ++plane) { long * const temperr = fserrP->thiserr[plane]; fserrP->thiserr[plane] = fserrP->nexterr[plane]; fserrP->nexterr[plane] = temperr; } if (fserrP->fsForward) fserr_setBackward(fserrP); else fserr_setForward(fserrP); } struct colormapFinder { /*---------------------------------------------------------------------------- This is an object that finds a color in a colormap. The methods 'searchColormapClose' and 'searchColormapExact' belong to it. This object ought to encompass the hash table as well some day and possibly encapsulate the color map altogether and just be an object that opaquely maps input colors to output colors. -----------------------------------------------------------------------------*/ tupletable colormap; unsigned int colors; /* Number of colors in 'colormap'. At least 1 */ unsigned int distanceDivider; /* The value by which our intermediate distance calculations have to be divided to make sure we don't overflow our unsigned int data structure. To the extent 'distanceDivider' is greater than 1, closest color results will be approximate -- there could conceivably be a closer one that we miss. */ }; static void createColormapFinder(struct pam * const pamP, tupletable const colormap, unsigned int const colors, struct colormapFinder ** const colormapFinderPP) { struct colormapFinder * colormapFinderP; MALLOCVAR_NOFAIL(colormapFinderP); colormapFinderP->colormap = colormap; colormapFinderP->colors = colors; { unsigned int const maxHandleableSqrDiff = (unsigned int)UINT_MAX / pamP->depth; if (SQR(pamP->maxval) > maxHandleableSqrDiff) colormapFinderP->distanceDivider = (unsigned int) (SQR(pamP->maxval) / maxHandleableSqrDiff + 0.1 + 1.0); /* The 0.1 is a fudge factor to keep us out of rounding trouble. The 1.0 effects a round-up. */ else colormapFinderP->distanceDivider = 1; } *colormapFinderPP = colormapFinderP; } static void destroyColormapFinder(struct colormapFinder * const colormapFinderP) { free(colormapFinderP); } static void searchColormapClose(struct pam * const pamP, tuple const tuple, struct colormapFinder * const colorFinderP, int * const colormapIndexP) { /*---------------------------------------------------------------------------- Search the colormap indicated by *colorFinderP for the color closest to that of tuple 'tuple'. Return its index as *colormapIndexP. *pamP describes the tuple 'tuple' and *colorFinderP has to be compatible with it (i.e. the tuples in the color map must also be described by *pamP). We compute distance between colors simply as the cartesian distance between them in the RGB space. An alternative would be to look at the chromaticities and luminosities of the colors. In experiments in 2003, we found that this was actually worse in many cases. One might think that two colors are closer if they have similar hues than when they are simply different brightnesses of the same hue. Human subjects asked to compare two colors normally say so. But when replacing the color of a pixel in an image, the luminosity is much more important, because you need to retain the luminosity relationship between adjacent pixels. If you replace a pixel with one that has the same chromaticity as the original, but much darker, it may stand out among its neighbors in a way the original pixel did not. In fact, on an image with blurred edges, we saw ugly effects at the edges when we substituted colors using a chromaticity-first color closeness formula. -----------------------------------------------------------------------------*/ unsigned int i; unsigned int dist; /* The closest distance we've found so far between the value of tuple 'tuple' and a tuple in the colormap. This is measured as the square of the cartesian distance between the tuples, except that it's divided by 'distanceDivider' to make sure it will fit in an unsigned int. */ dist = UINT_MAX; /* initial value */ assert(colorFinderP->colors > 0); for (i = 0; i < colorFinderP->colors; ++i) { unsigned int newdist; /* candidate for new 'dist' value */ unsigned int plane; newdist = 0; for (plane=0; plane < pamP->depth; ++plane) { newdist += SQR(tuple[plane] - colorFinderP->colormap[i]->tuple[plane]) / colorFinderP->distanceDivider; } if (newdist < dist) { *colormapIndexP = i; dist = newdist; } } } static void searchColormapExact(struct pam * const pamP, struct colormapFinder * const colorFinderP, tuple const tuple, int * const colormapIndexP, bool * const foundP) { /*---------------------------------------------------------------------------- Search the colormap indicated by *colorFinderP for the color of tuple 'tuple'. If it's in the map, return its index as *colormapIndexP and return *foundP == TRUE. Otherwise, return *foundP = FALSE. *pamP describes the tuple 'tuple' and *colorFinderP has to be compatible with it (i.e. the tuples in the color map must also be described by *pamP). -----------------------------------------------------------------------------*/ unsigned int i; bool found; found = FALSE; /* initial value */ for (i = 0; i < colorFinderP->colors && !found; ++i) { unsigned int plane; found = TRUE; /* initial assumption */ for (plane=0; plane < pamP->depth; ++plane) if (tuple[plane] != colorFinderP->colormap[i]->tuple[plane]) found = FALSE; if (found) *colormapIndexP = i; } *foundP = found; } static void lookupThroughHash(struct pam * const pamP, tuple const tuple, bool const needExactMatch, struct colormapFinder * const colorFinderP, tuplehash const colorhash, int * const colormapIndexP, bool * const usehashP) { /*---------------------------------------------------------------------------- Look up the color of tuple 'tuple' in the color map indicated by 'colorFinderP' and, if it's in there, return its index as *colormapIndexP. If not, return *colormapIndexP == -1. Both the tuple 'tuple' and the colors in color map 'colormap' are described by *pamP. If 'needExactMatch' isn't true, we find the closest color in the color map, and never return *colormapIndex == -1. lookaside at the hash table 'colorhash' to possibly avoid the cost of a full lookup. If we do a full lookup, we add the result to 'colorhash' unless *usehashP is false, and if that makes 'colorhash' full, we set *usehashP false. -----------------------------------------------------------------------------*/ int found; /* Check hash table to see if we have already matched this color. */ pnm_lookuptuple(pamP, colorhash, tuple, &found, colormapIndexP); if (!found) { /* No, have to do a full lookup */ if (needExactMatch) { bool found; searchColormapExact(pamP, colorFinderP, tuple, colormapIndexP, &found); if (!found) *colormapIndexP = -1; } else searchColormapClose(pamP, tuple, colorFinderP, colormapIndexP); if (*usehashP) { int fits; pnm_addtotuplehash(pamP, colorhash, tuple, *colormapIndexP, &fits); if (!fits) { pm_message("out of memory adding to hash table; " "proceeding without it"); *usehashP = FALSE; } } } } static void mapTuple(struct pam * const pamP, tuple const inTuple, tuple const defaultColor, tupletable const colormap, struct colormapFinder * const colorFinderP, tuplehash const colorhash, bool * const usehashP, tuple const outTuple, bool * const missingP) { int colormapIndex; /* Index into the colormap of the replacement color, or -1 if there is no usable color in the color map. */ lookupThroughHash(pamP, inTuple, !!defaultColor, colorFinderP, colorhash, &colormapIndex, usehashP); if (colormapIndex == -1) { *missingP = TRUE; assert(defaultColor); /* Otherwise, lookup would have succeeded */ pnm_assigntuple(pamP, outTuple, defaultColor); } else { *missingP = FALSE; pnm_assigntuple(pamP, outTuple, colormap[colormapIndex]->tuple); } } static void convertRowStraight(struct pam * const inpamP, struct pam * const outpamP, tuple inrow[], depthAdjustment const depthAdjustment, tupletable const colormap, struct colormapFinder * const colorFinderP, tuplehash const colorhash, bool * const usehashP, tuple const defaultColor, tuple outrow[], unsigned int * const missingCountP) { /*---------------------------------------------------------------------------- Like convertRow(), compute outrow[] from inrow[], replacing each pixel with the new colors. Do a straight pixel for pixel remap; no dithering. Return the number of pixels that were not matched in the color map as *missingCountP. *colorFinderP is a color finder based on 'colormap' -- it tells us what index of 'colormap' corresponds to a certain color. -----------------------------------------------------------------------------*/ unsigned int col; unsigned int missingCount; /* The following modify tuplerow, to make it consistent with *outpamP instead of *inpamP. */ assert(outpamP->allocation_depth >= inpamP->depth); pnm_scaletuplerow(inpamP, outrow, inrow, outpamP->maxval); adjustDepthRow(outrow, outpamP->width, depthAdjustment); missingCount = 0; /* initial value */ for (col = 0; col < outpamP->width; ++col) { bool missing; mapTuple(outpamP, outrow[col], defaultColor, colormap, colorFinderP, colorhash, usehashP, outrow[col], &missing); if (missing) ++missingCount; } *missingCountP = missingCount; } static void convertRowDither(struct pam * const inpamP, struct pam * const outpamP, tuple const inrow[], depthAdjustment const depthAdjustment, tupletable const colormap, struct colormapFinder * const colorFinderP, tuplehash const colorhash, bool * const usehashP, tuple const defaultColor, struct Fserr * const fserrP, tuple outrow[], unsigned int * const missingCountP) { /*---------------------------------------------------------------------------- Like convertRow(), compute outrow[] from inrow[], replacing each pixel with the new colors. Do a Floyd-Steinberg dither, using and updating the error accumulator *fserrP. Return the number of pixels that were not matched in the color map as *missingCountP. *colorFinderP is a color finder based on 'colormap' -- it tells us what index of 'colormap' corresponds to a certain color. -----------------------------------------------------------------------------*/ tuple const ditheredTuple = pnm_allocpamtuple(inpamP); /* The input tuple we're converting, adjusted by the dither */ tuple const normTuple = pnm_allocpamtuple(outpamP); /* Same as above, normalized to the maxval of the output file / colormap. */ unsigned int missingCount; int col; floydInitRow(inpamP, fserrP); missingCount = 0; /* initial value */ for (col = fserrP->begCol; col != fserrP->endCol; col += fserrP->step) { bool missing; floydAdjustColor(inpamP, inrow[col], ditheredTuple, fserrP, col); /* Convert tuple to the form of those in the colormap */ assert(outpamP->allocation_depth >= inpamP->depth); pnm_scaletuple(inpamP, normTuple, ditheredTuple, outpamP->maxval); adjustDepthTuple(normTuple, depthAdjustment); mapTuple(outpamP, normTuple, defaultColor, colormap, colorFinderP, colorhash, usehashP, outrow[col], &missing); if (missing) ++missingCount; /* Convert tuple back to the form of the input, where dithering takes place. */ pnm_scaletuple(outpamP, normTuple, outrow[col], inpamP->maxval); inverseAdjustDepthTuple(normTuple, depthAdjustment); floydPropagateErr(inpamP, fserrP, col, inrow[col], normTuple); } floydSwitchDir(inpamP, fserrP); pnm_freepamtuple(normTuple); pnm_freepamtuple(ditheredTuple); *missingCountP = missingCount; } static void convertRow(struct pam * const inpamP, struct pam * const outpamP, tuple inrow[], depthAdjustment depthAdjustment, tupletable const colormap, struct colormapFinder * const colorFinderP, tuplehash const colorhash, bool * const usehashP, bool const floyd, tuple const defaultColor, struct Fserr * const fserrP, tuple outrow[], unsigned int * const missingCountP) { /*---------------------------------------------------------------------------- Replace the colors in row tuplerow[] (described by *inpamP) with the new colors and convert so it is described by *outpamP. Use and update the Floyd-Steinberg state *fserrP. Return the number of pixels that were not matched in the color map as *missingCountP. *colorFinderP is a color finder based on 'colormap' -- it tells us what index of 'colormap' corresponds to a certain color. outrow[] doubles as a work space, so we require it to have an allocation depth at least as great as that of inrow[]. -----------------------------------------------------------------------------*/ /* The following both consults and adds to 'colorhash' and its associated '*usehashP'. It modifies 'tuplerow' too. */ if (floyd) convertRowDither(inpamP, outpamP, inrow, depthAdjustment, colormap, colorFinderP, colorhash, usehashP, defaultColor, fserrP, outrow, missingCountP); else convertRowStraight(inpamP, outpamP, inrow, depthAdjustment, colormap, colorFinderP, colorhash, usehashP, defaultColor, outrow, missingCountP); } static void copyRaster(struct pam * const inpamP, struct pam * const outpamP, tupletable const colormap, unsigned int const colormapSz, bool const floyd, struct Random const random, tuple const defaultColor, unsigned int * const missingCountP) { tuplehash const colorhash = pnm_createtuplehash(); tuple * inrow; tuple * outrow; struct pam workpam; /* This is for work space we use for building up the output pixels. To save time and memory, we modify them in place in a buffer, which ultimately holds the output pixels. This pam structure is thus the same as the *outpamP, but with a tuple allocation depth large enough to handle intermediate results. */ depthAdjustment depthAdjustment; struct colormapFinder * colorFinderP; bool usehash; struct Fserr fserr; int row; workpam = *outpamP; workpam.allocation_depth = MAX(workpam.depth, inpamP->depth); workpam.size = sizeof(workpam); workpam.len = PAM_STRUCT_SIZE(allocation_depth); inrow = pnm_allocpamrow(inpamP); outrow = pnm_allocpamrow(&workpam); selectDepthAdjustment(inpamP, outpamP->depth, &depthAdjustment); usehash = TRUE; createColormapFinder(outpamP, colormap, colormapSz, &colorFinderP); if (floyd) fserr_init(inpamP, &fserr, random); *missingCountP = 0; /* initial value */ for (row = 0; row < inpamP->height; ++row) { unsigned int missingCount; pnm_readpamrow(inpamP, inrow); convertRow(inpamP, &workpam, inrow, depthAdjustment, colormap, colorFinderP, colorhash, &usehash, floyd, defaultColor, &fserr, outrow, &missingCount); *missingCountP += missingCount; pnm_writepamrow(outpamP, outrow); } destroyColormapFinder(colorFinderP); pnm_freepamrow(inrow); pnm_freepamrow(outrow); pnm_destroytuplehash(colorhash); } static void remap(FILE * const ifP, const struct pam * const outpamCommonP, tupletable const colormap, unsigned int const colormapSz, bool const floyd, struct Random const random, tuple const defaultColor, bool const verbose) { /*---------------------------------------------------------------------------- Remap the pixels from the raster on *ifP to the 'colormapSz' colors in 'colormap'. Where the input pixel's color is in the map, just use that for the output. Where it isn't, use 'defaultColor', except if that is NULL, use the closest color in the map to the input color. But if 'floyd' is true and 'defaultColor' is NULL, also do Floyd-Steinberg dithering on the output so the aggregate color of a region is about the same as that of the input even though the individual pixels have different colors. -----------------------------------------------------------------------------*/ int eof; eof = FALSE; while (!eof) { struct pam inpam, outpam; unsigned int missingCount; /* Number of pixels that were mapped to 'defaultColor' because they weren't present in the color map. */ pnm_readpaminit(ifP, &inpam, PAM_STRUCT_SIZE(allocation_depth)); outpam = *outpamCommonP; outpam.width = inpam.width; outpam.height = inpam.height; if (outpam.maxval != inpam.maxval && defaultColor) pm_error("The maxval of the colormap (%u) is not equal to the " "maxval of the input image (%u). This is allowable only " "if you are doing an approximate mapping (i.e. you don't " "specify -firstisdefault or -missingcolor)", (unsigned int)outpam.maxval, (unsigned int)inpam.maxval); pnm_writepaminit(&outpam); /* Set up so input buffers have extra space as needed to convert the input to the output depth. */ pnm_setminallocationdepth(&inpam, outpam.depth); copyRaster(&inpam, &outpam, colormap, colormapSz, floyd, random, defaultColor, &missingCount); if (verbose) pm_message("%u pixels not matched in color map", missingCount); pnm_nextimage(ifP, &eof); } } static void processMapFile(const char * const mapFileNm, struct pam * const outpamCommonP, tupletable * const colormapP, unsigned int * const colormapSzP, tuple * const firstColorP) { /*---------------------------------------------------------------------------- Read a color map from the file named 'mapFileNm'. It's a map that associates each color in that file with a unique whole number. Return the map as *colormapP, with the number of entries in it as *colormapSzP. Also determine the first color (top left) in the map file and return that as *firstColorP. -----------------------------------------------------------------------------*/ FILE * mapfile; struct pam mappam; tuple ** maptuples; tuple firstColor; mapfile = pm_openr(mapFileNm); maptuples = pnm_readpam(mapfile, &mappam, PAM_STRUCT_SIZE(tuple_type)); pm_close(mapfile); computeColorMapFromMap(&mappam, maptuples, colormapP, colormapSzP); firstColor = pnm_allocpamtuple(&mappam); pnm_assigntuple(&mappam, firstColor, maptuples[0][0]); *firstColorP = firstColor; pnm_freepamarray(maptuples, &mappam); *outpamCommonP = mappam; outpamCommonP->file = stdout; } static void getSpecifiedMissingColor(struct pam * const pamP, const char * const colorNm, tuple * const specColorP) { tuple specColor; specColor = pnm_allocpamtuple(pamP); if (colorNm) { pixel const color = ppm_parsecolor(colorNm, pamP->maxval); if (pamP->depth == 3) { specColor[PAM_RED_PLANE] = PPM_GETR(color); specColor[PAM_GRN_PLANE] = PPM_GETG(color); specColor[PAM_BLU_PLANE] = PPM_GETB(color); } else if (pamP->depth == 1) { specColor[0] = ppm_luminosity(color); } else { pm_error("You may not use -missing with a colormap that is not " "of depth 1 or 3. Yours has depth %u", pamP->depth); } } *specColorP = specColor; } int main(int argc, const char * argv[] ) { struct CmdlineInfo cmdline; FILE * ifP; struct pam outpamCommon; /* Describes the output images. Width and height fields are not meaningful, because different output images might have different dimensions. The rest of the information is common across all output images. */ tupletable colormap; unsigned int colormapSz; tuple specColor; /* A tuple of the color the user specified to use for input colors that are not in the colormap. Arbitrary tuple if he didn't specify any. */ tuple firstColor; /* A tuple of the first color present in the map file */ tuple defaultColor; /* The color to which we will map an input color that is not in the colormap. NULL if we are not to map such a color to a particular color (i.e. we'll choose an approximate match from the map). */ pm_proginit(&argc, argv); parseCommandLine(argc, argv, &cmdline); ifP = pm_openr(cmdline.inputFilespec); processMapFile(cmdline.mapFilespec, &outpamCommon, &colormap, &colormapSz, &firstColor); getSpecifiedMissingColor(&outpamCommon, cmdline.missingcolor, &specColor); switch (cmdline.missingMethod) { case MISSING_CLOSE: defaultColor = NULL; break; case MISSING_FIRST: defaultColor = firstColor; break; case MISSING_SPECIFIED: defaultColor = specColor; break; } remap(ifP, &outpamCommon, colormap, colormapSz, cmdline.floyd, cmdline.random, defaultColor, cmdline.verbose); pnm_freepamtuple(firstColor); pnm_freepamtuple(specColor); pm_close(stdout); pm_close(ifP); return 0; }