diff options
Diffstat (limited to 'converter/other/pamtoxvmini.c')
| -rw-r--r-- | converter/other/pamtoxvmini.c | 250 |
1 files changed, 250 insertions, 0 deletions
diff --git a/converter/other/pamtoxvmini.c b/converter/other/pamtoxvmini.c new file mode 100644 index 00000000..dc56e912 --- /dev/null +++ b/converter/other/pamtoxvmini.c @@ -0,0 +1,250 @@ +/*============================================================================= + pamtoxvmini +=============================================================================== + Convert Netpbm image to XV mini thumbnail. + + Written by Bryan Henderson in April 2006 and contributed to the public + domain. +=============================================================================*/ + +#include <assert.h> +#include <limits.h> +#include <string.h> + +#include "pm_c_util.h" +#include "nstring.h" +#include "pam.h" +#include "pammap.h" + +typedef struct xvPalette { + unsigned int red[256]; + unsigned int grn[256]; + unsigned int blu[256]; +} xvPalette; + + +struct cmdlineInfo { + const char * inputFileName; +}; + + + +static void +parseCommandLine(int const argc, + char * argv[], + struct cmdlineInfo * const cmdlineP) { + + if (argc-1 < 1) + cmdlineP->inputFileName = "-"; + else { + cmdlineP->inputFileName = argv[1]; + + if (argc-1 > 1) + pm_error("Too many arguments: %u. Only argument is optional " + "input file name.", argc-1); + } +} + + + +static void +makeXvPalette(xvPalette * const xvPaletteP) { + + unsigned int paletteIndex; + unsigned int r; + + paletteIndex = 0; + + for (r = 0; r < 8; ++r) { + unsigned int g; + for (g = 0; g < 8; ++g) { + unsigned int b; + for (b = 0; b < 4; ++b) { + xvPaletteP->red[paletteIndex] = (r*255)/7; + xvPaletteP->grn[paletteIndex] = (g*255)/7; + xvPaletteP->blu[paletteIndex] = (b*255)/3; + ++paletteIndex; + } + } + } + +} + + + +static void +writeXvHeader(FILE * const ofP, + unsigned int const cols, + unsigned int const rows, + unsigned int const maxval) { + + fprintf(ofP, "P7 332\n"); + + fprintf(ofP, "# Created by Pamtoxvmini\n"); + fprintf(ofP, "#END_OF_COMMENTS\n"); + + fprintf(ofP, "%u %u %u\n", cols, rows, maxval); +} + + + +static void +findClosestColor(struct pam * const pamP, + tuple const tuple, + const xvPalette * const xvPaletteP, + unsigned int * const paletteIndexP) { +/*---------------------------------------------------------------------------- + Find the color in the palette *xvPaletteP that is closest to the color + 'tuple' and return its index in the palette. +-----------------------------------------------------------------------------*/ + unsigned int paletteIndex; + unsigned int bestPaletteIndex; + unsigned int bestDistanceSoFar; + + /* An entry condition is that the tuple have the same form as the + colors in the XV palette: + */ + assert(pamP->depth >= 3); + assert(pamP->maxval = 255); + + bestPaletteIndex = 0; + bestDistanceSoFar = UINT_MAX; + + for (paletteIndex = 0; paletteIndex < 256; ++paletteIndex) { + unsigned int const tupleRed = tuple[PAM_RED_PLANE]; + unsigned int const tupleGrn = tuple[PAM_GRN_PLANE]; + unsigned int const tupleBlu = tuple[PAM_BLU_PLANE]; + + unsigned int const paletteRed = xvPaletteP->red[paletteIndex]; + unsigned int const paletteGrn = xvPaletteP->grn[paletteIndex]; + unsigned int const paletteBlu = xvPaletteP->blu[paletteIndex]; + + unsigned int const distance = + SQR((int)tupleRed - (int)paletteRed) + + SQR((int)tupleGrn - (int)paletteGrn) + + SQR((int)tupleBlu - (int)paletteBlu); + + if (distance < bestDistanceSoFar) { + bestDistanceSoFar = distance; + bestPaletteIndex = paletteIndex; + } + } + *paletteIndexP = bestPaletteIndex; +} + + + +static void +getPaletteIndexThroughCache(struct pam * const pamP, + tuple const tuple, + const xvPalette * const xvPaletteP, + tuplehash const paletteHash, + unsigned int * const paletteIndexP) { +/*---------------------------------------------------------------------------- + Return as *paletteIndexP the index into the palette *xvPaletteP of + the color that most closely resembles the color 'tuple'. + + Use the hash table *paletteIndexP as a cache to speed up the search. + If the tuple-index association is in *paletteIndexP, use it. If not, + find it the hard way and add it to *palettedIndexP for the next guy. +-----------------------------------------------------------------------------*/ + bool found; + int paletteIndex; + + pnm_lookuptuple(pamP, paletteHash, tuple, &found, &paletteIndex); + if (found) + *paletteIndexP = paletteIndex; + else { + bool fits; + findClosestColor(pamP, tuple, xvPaletteP, paletteIndexP); + + pnm_addtotuplehash(pamP, paletteHash, tuple, *paletteIndexP, &fits); + + if (!fits) + pm_error("Can't get memory for palette hash."); + } +} + + + +static void +writeXvRaster(struct pam * const pamP, + xvPalette * const xvPaletteP, + FILE * const ofP) { +/*---------------------------------------------------------------------------- + Write out the XV image, from the Netpbm input file ifP, which is + positioned to the raster. + + The XV raster contains palette indices into the palette *xvPaletteP. + + If there is any color in the image which is not in the palette, we + fail the program. We really should use the closest color in the palette + instead. +-----------------------------------------------------------------------------*/ + tuplehash paletteHash; + tuple * tuplerow; + unsigned int row; + unsigned char * xvrow; + + paletteHash = pnm_createtuplehash(); + + tuplerow = pnm_allocpamrow(pamP); + xvrow = (unsigned char*)pm_allocrow(pamP->width, 1); + + for (row = 0; row < pamP->height; ++row) { + unsigned int col; + + pnm_readpamrow(pamP, tuplerow); + pnm_scaletuplerow(pamP, tuplerow, tuplerow, 255); + pnm_makerowrgb(pamP, tuplerow); + + for (col = 0; col < pamP->width; ++col) { + unsigned int paletteIndex; + + getPaletteIndexThroughCache(pamP, tuplerow[col], xvPaletteP, + paletteHash, &paletteIndex); + + assert(paletteIndex < 256); + + xvrow[col] = paletteIndex; + } + fwrite(xvrow, 1, pamP->width, ofP); + } + + pm_freerow((char*)xvrow); + pnm_freepamrow(pamP); + + pnm_destroytuplehash(paletteHash); +} + + + +int +main(int argc, + char * argv[]) { + + struct cmdlineInfo cmdline; + FILE * ifP; + struct pam pam; + xvPalette xvPalette; + + ppm_init(&argc, argv); + + parseCommandLine(argc, argv, &cmdline); + + ifP = pm_openr(cmdline.inputFileName); + + makeXvPalette(&xvPalette); + + pnm_readpaminit(ifP, &pam, PAM_STRUCT_SIZE(allocation_depth)); + + pnm_setminallocationdepth(&pam, 3); + + writeXvHeader(stdout, pam.width, pam.height, pam.maxval); + + writeXvRaster(&pam, &xvPalette, stdout); + + pm_close(ifP); + + return 0; +} |