diff options
Diffstat (limited to 'png2ff.c')
| -rw-r--r-- | png2ff.c | 96 |
1 files changed, 80 insertions, 16 deletions
@@ -5,11 +5,21 @@ #include <stdint.h> #include <stdio.h> #include <stdlib.h> +#include <string.h> +#include <lcms2.h> #include <png.h> static char *argv0; +/* ProPhoto RGB */ +static cmsCIExyYTRIPLE primaries = { + /* x, y, Y */ + { 0.7347, 0.2653, 0.288040 }, /* red */ + { 0.1596, 0.8404, 0.711874 }, /* green */ + { 0.0366, 0.0001, 0.000086 }, /* blue */ +}; + void pngerr(png_structp png_struct_p, png_const_charp msg) { @@ -20,11 +30,16 @@ pngerr(png_structp png_struct_p, png_const_charp msg) int main(int argc, char *argv[]) { + cmsHPROFILE in_profile, out_profile; + cmsHTRANSFORM transform; + cmsToneCurve *gamma18, *out_curves[3]; png_structp png_struct_p; png_infop png_info_p; - png_bytepp png_row_p; - uint32_t width, height, png_row_len, tmp32, r, i; - uint16_t tmp16; + png_bytepp png_row_p, icc_data = NULL; + png_charpp icc_name = NULL; + uint32_t width, height, icc_len, outrowlen, tmp32, r, i; + uint16_t *inrow, *outrow; + int icc_compression; argv0 = argv[0], argc--, argv++; @@ -53,9 +68,33 @@ main(int argc, char *argv[]) PNG_TRANSFORM_EXPAND, NULL); width = png_get_image_width(png_struct_p, png_info_p); height = png_get_image_height(png_struct_p, png_info_p); - png_row_len = png_get_rowbytes(png_struct_p, png_info_p); png_row_p = png_get_rows(png_struct_p, png_info_p); + /* icc profile (output ProPhoto RGB) */ + if (png_get_valid(png_struct_p, png_info_p, PNG_INFO_iCCP)) { + png_get_iCCP(png_struct_p, png_info_p, icc_name, + &icc_compression, icc_data, &icc_len); + if (!(in_profile = cmsOpenProfileFromMem(icc_data, + icc_len))) + goto lcmserr; + } else { + if (!(in_profile = cmsCreate_sRGBProfile())) + goto lcmserr; + } + if (!(gamma18 = cmsBuildGamma(NULL, 1.8))) + goto lcmserr; + out_curves[0] = out_curves[1] = out_curves[2] = gamma18; + if (!(out_profile = cmsCreateRGBProfile(cmsD50_xyY(), &primaries, + out_curves))) + goto lcmserr; + + /* allocate row buffer */ + outrowlen = width * strlen("RGBA"); + if (!(outrow = malloc(outrowlen * sizeof(uint16_t)))) { + fprintf(stderr, "%s: malloc: out of memory\n", argv0); + return 1; + } + /* write header */ fputs("farbfeld", stdout); tmp32 = htonl(width); @@ -68,25 +107,46 @@ main(int argc, char *argv[]) /* write data */ switch(png_get_bit_depth(png_struct_p, png_info_p)) { case 8: + if (!(transform = cmsCreateTransform(in_profile, + TYPE_RGBA_8, out_profile, TYPE_RGBA_16, + INTENT_RELATIVE_COLORIMETRIC, 0))) + goto lcmserr; for (r = 0; r < height; ++r) { - for (i = 0; i < png_row_len; i++) { - /* ((2^16-1) / 255) == 257 */ - tmp16 = htons(257 * png_row_p[r][i]); - if (fwrite(&tmp16, sizeof(uint16_t), 1, - stdout) != 1) - goto writerr; + cmsDoTransform(transform, png_row_p[r], outrow, width); + for (i = 0; i < outrowlen; i++) { + /* re-add alpha */ + if (i >= 3 && (i - 3) % 4 == 0) + outrow[i] = 257 * png_row_p[r][i]; + /* swap endiannes to BE */ + outrow[i] = htons(outrow[i]); } + if (fwrite(outrow, sizeof(uint16_t), outrowlen, + stdout) != outrowlen) + goto writerr; } break; case 16: + if (!(transform = cmsCreateTransform(in_profile, + TYPE_RGBA_16, out_profile, TYPE_RGBA_16, + INTENT_RELATIVE_COLORIMETRIC, 0))) + goto lcmserr; for (r = 0; r < height; ++r) { - for (i = 0; i < png_row_len / 2; i++) { - tmp16 = *((uint16_t *)(png_row_p[r] + - 2 * i)); - if (fwrite(&tmp16, sizeof(uint16_t), 1, - stdout) != 1) - goto writerr; + inrow = (uint16_t *)png_row_p[r]; + for (i = 0; i < outrowlen; i++) { + /* swap endianness to LE */ + inrow[i] = ntohs(inrow[i]); + } + cmsDoTransform(transform, png_row_p[r], outrow, width); + for (i = 0; i < outrowlen; ++i) { + /* re-add alpha */ + if (i >= 3 && (i - 3) % 4 == 0) + outrow[i] = inrow[i]; + /* swap endianness to BE */ + outrow[i] = htons(outrow[i]); } + if (fwrite(outrow, sizeof(uint16_t), outrowlen, + stdout) != outrowlen) + goto writerr; } break; default: @@ -102,4 +162,8 @@ writerr: perror(NULL); return 1; +lcmserr: + fprintf(stderr, "%s: lcms error\n", argv0); + + return 1; } |