#include "mupdf/fitz.h" /* * TIFF image loader. Should be enough to support TIFF files in XPS. * Baseline TIFF 6.0 plus CMYK, LZW, Flate and JPEG support. * Limited bit depths (1,2,4,8). * Limited planar configurations (1=chunky). * No tiles (easy fix if necessary). * TODO: RGBPal images */ struct tiff { fz_context *ctx; /* "file" */ unsigned char *bp, *rp, *ep; /* byte order */ unsigned order; /* offset of first ifd */ unsigned ifd_offset; /* where we can find the strips of image data */ unsigned rowsperstrip; unsigned *stripoffsets; unsigned *stripbytecounts; /* colormap */ unsigned *colormap; unsigned stripoffsetslen; unsigned stripbytecountslen; unsigned colormaplen; /* assorted tags */ unsigned subfiletype; unsigned photometric; unsigned compression; unsigned imagewidth; unsigned imagelength; unsigned samplesperpixel; unsigned bitspersample; unsigned planar; unsigned extrasamples; unsigned xresolution; unsigned yresolution; unsigned resolutionunit; unsigned fillorder; unsigned g3opts; unsigned g4opts; unsigned predictor; unsigned ycbcrsubsamp[2]; unsigned char *jpegtables; /* point into "file" buffer */ unsigned jpegtableslen; unsigned char *profile; int profilesize; /* decoded data */ fz_colorspace *colorspace; unsigned char *samples; int stride; }; enum { TII = 0x4949, /* 'II' */ TMM = 0x4d4d, /* 'MM' */ TBYTE = 1, TASCII = 2, TSHORT = 3, TLONG = 4, TRATIONAL = 5 }; #define NewSubfileType 254 #define ImageWidth 256 #define ImageLength 257 #define BitsPerSample 258 #define Compression 259 #define PhotometricInterpretation 262 #define FillOrder 266 #define StripOffsets 273 #define SamplesPerPixel 277 #define RowsPerStrip 278 #define StripByteCounts 279 #define XResolution 282 #define YResolution 283 #define PlanarConfiguration 284 #define T4Options 292 #define T6Options 293 #define ResolutionUnit 296 #define Predictor 317 #define ColorMap 320 #define TileWidth 322 #define TileLength 323 #define TileOffsets 324 #define TileByteCounts 325 #define ExtraSamples 338 #define JPEGTables 347 #define YCbCrSubSampling 520 #define ICCProfile 34675 static const unsigned char bitrev[256] = { 0x00, 0x80, 0x40, 0xc0, 0x20, 0xa0, 0x60, 0xe0, 0x10, 0x90, 0x50, 0xd0, 0x30, 0xb0, 0x70, 0xf0, 0x08, 0x88, 0x48, 0xc8, 0x28, 0xa8, 0x68, 0xe8, 0x18, 0x98, 0x58, 0xd8, 0x38, 0xb8, 0x78, 0xf8, 0x04, 0x84, 0x44, 0xc4, 0x24, 0xa4, 0x64, 0xe4, 0x14, 0x94, 0x54, 0xd4, 0x34, 0xb4, 0x74, 0xf4, 0x0c, 0x8c, 0x4c, 0xcc, 0x2c, 0xac, 0x6c, 0xec, 0x1c, 0x9c, 0x5c, 0xdc, 0x3c, 0xbc, 0x7c, 0xfc, 0x02, 0x82, 0x42, 0xc2, 0x22, 0xa2, 0x62, 0xe2, 0x12, 0x92, 0x52, 0xd2, 0x32, 0xb2, 0x72, 0xf2, 0x0a, 0x8a, 0x4a, 0xca, 0x2a, 0xaa, 0x6a, 0xea, 0x1a, 0x9a, 0x5a, 0xda, 0x3a, 0xba, 0x7a, 0xfa, 0x06, 0x86, 0x46, 0xc6, 0x26, 0xa6, 0x66, 0xe6, 0x16, 0x96, 0x56, 0xd6, 0x36, 0xb6, 0x76, 0xf6, 0x0e, 0x8e, 0x4e, 0xce, 0x2e, 0xae, 0x6e, 0xee, 0x1e, 0x9e, 0x5e, 0xde, 0x3e, 0xbe, 0x7e, 0xfe, 0x01, 0x81, 0x41, 0xc1, 0x21, 0xa1, 0x61, 0xe1, 0x11, 0x91, 0x51, 0xd1, 0x31, 0xb1, 0x71, 0xf1, 0x09, 0x89, 0x49, 0xc9, 0x29, 0xa9, 0x69, 0xe9, 0x19, 0x99, 0x59, 0xd9, 0x39, 0xb9, 0x79, 0xf9, 0x05, 0x85, 0x45, 0xc5, 0x25, 0xa5, 0x65, 0xe5, 0x15, 0x95, 0x55, 0xd5, 0x35, 0xb5, 0x75, 0xf5, 0x0d, 0x8d, 0x4d, 0xcd, 0x2d, 0xad, 0x6d, 0xed, 0x1d, 0x9d, 0x5d, 0xdd, 0x3d, 0xbd, 0x7d, 0xfd, 0x03, 0x83, 0x43, 0xc3, 0x23, 0xa3, 0x63, 0xe3, 0x13, 0x93, 0x53, 0xd3, 0x33, 0xb3, 0x73, 0xf3, 0x0b, 0x8b, 0x4b, 0xcb, 0x2b, 0xab, 0x6b, 0xeb, 0x1b, 0x9b, 0x5b, 0xdb, 0x3b, 0xbb, 0x7b, 0xfb, 0x07, 0x87, 0x47, 0xc7, 0x27, 0xa7, 0x67, 0xe7, 0x17, 0x97, 0x57, 0xd7, 0x37, 0xb7, 0x77, 0xf7, 0x0f, 0x8f, 0x4f, 0xcf, 0x2f, 0xaf, 0x6f, 0xef, 0x1f, 0x9f, 0x5f, 0xdf, 0x3f, 0xbf, 0x7f, 0xff }; static void fz_decode_tiff_uncompressed(struct tiff *tiff, fz_stream *stm, unsigned char *wp, int wlen) { fz_read(stm, wp, wlen); fz_close(stm); } static void fz_decode_tiff_packbits(struct tiff *tiff, fz_stream *chain, unsigned char *wp, int wlen) { fz_stream *stm = fz_open_rld(chain); fz_read(stm, wp, wlen); fz_close(stm); } static void fz_decode_tiff_lzw(struct tiff *tiff, fz_stream *chain, unsigned char *wp, int wlen) { fz_stream *stm = fz_open_lzwd(chain, 1); fz_read(stm, wp, wlen); fz_close(stm); } static void fz_decode_tiff_flate(struct tiff *tiff, fz_stream *chain, unsigned char *wp, int wlen) { fz_stream *stm = fz_open_flated(chain); fz_read(stm, wp, wlen); fz_close(stm); } static void fz_decode_tiff_fax(struct tiff *tiff, int comp, fz_stream *chain, unsigned char *wp, int wlen) { fz_stream *stm; int black_is_1 = tiff->photometric == 0; int k = comp == 4 ? -1 : 0; int encoded_byte_align = comp == 2; stm = fz_open_faxd(chain, k, 0, encoded_byte_align, tiff->imagewidth, tiff->imagelength, 0, black_is_1); fz_read(stm, wp, wlen); fz_close(stm); } static void fz_decode_tiff_jpeg(struct tiff *tiff, fz_stream *chain, unsigned char *wp, int wlen) { fz_stream *stm; fz_stream *jpegtables = NULL; int color_transform = -1; /* unset */ if (tiff->jpegtables && (int)tiff->jpegtableslen > 0) jpegtables = fz_open_memory(tiff->ctx, tiff->jpegtables, (int)tiff->jpegtableslen); if (tiff->photometric == 2 /* RGB */ || tiff->photometric == 3 /* RGBPal */) color_transform = 0; stm = fz_open_dctd(chain, color_transform, 0, jpegtables); fz_read(stm, wp, wlen); fz_close(stm); } static inline int getcomp(unsigned char *line, int x, int bpc) { switch (bpc) { case 1: return (line[x >> 3] >> ( 7 - (x & 7) ) ) & 1; case 2: return (line[x >> 2] >> ( ( 3 - (x & 3) ) << 1 ) ) & 3; case 4: return (line[x >> 1] >> ( ( 1 - (x & 1) ) << 2 ) ) & 15; case 8: return line[x]; case 16: return line[x << 1] << 8 | line[(x << 1) + 1]; } return 0; } static inline void putcomp(unsigned char *line, int x, int bpc, int value) { int maxval = (1 << bpc) - 1; switch (bpc) { case 1: line[x >> 3] &= ~(maxval << (7 - (x & 7))); break; case 2: line[x >> 2] &= ~(maxval << ((3 - (x & 3)) << 1)); break; case 4: line[x >> 1] &= ~(maxval << ((1 - (x & 1)) << 2)); break; } switch (bpc) { case 1: line[x >> 3] |= value << (7 - (x & 7)); break; case 2: line[x >> 2] |= value << ((3 - (x & 3)) << 1); break; case 4: line[x >> 1] |= value << ((1 - (x & 1)) << 2); break; case 8: line[x] = value; break; case 16: line[x << 1] = value >> 8; line[(x << 1) + 1] = value & 0xFF; break; } } static void fz_unpredict_tiff(unsigned char *line, int width, int comps, int bits) { unsigned char left[32]; int i, k, v; for (k = 0; k < comps; k++) left[k] = 0; for (i = 0; i < width; i++) { for (k = 0; k < comps; k++) { v = getcomp(line, i * comps + k, bits); v = v + left[k]; v = v % (1 << bits); putcomp(line, i * comps + k, bits, v); left[k] = v; } } } static void fz_invert_tiff(unsigned char *line, int width, int comps, int bits, int alpha) { int i, k, v; int m = (1 << bits) - 1; for (i = 0; i < width; i++) { for (k = 0; k < comps; k++) { v = getcomp(line, i * comps + k, bits); if (!alpha || k < comps - 1) v = m - v; putcomp(line, i * comps + k, bits, v); } } } static void fz_expand_tiff_colormap(struct tiff *tiff) { int maxval = 1 << tiff->bitspersample; unsigned char *samples; unsigned char *src, *dst; unsigned int x, y; unsigned int stride; /* colormap has first all red, then all green, then all blue values */ /* colormap values are 0..65535, bits is 4 or 8 */ /* image can be with or without extrasamples: comps is 1 or 2 */ if (tiff->samplesperpixel != 1 && tiff->samplesperpixel != 2) fz_throw(tiff->ctx, FZ_ERROR_GENERIC, "invalid number of samples for RGBPal"); if (tiff->bitspersample != 4 && tiff->bitspersample != 8) fz_throw(tiff->ctx, FZ_ERROR_GENERIC, "invalid number of bits for RGBPal"); if (tiff->colormaplen < (unsigned)maxval * 3) fz_throw(tiff->ctx, FZ_ERROR_GENERIC, "insufficient colormap data"); stride = tiff->imagewidth * (tiff->samplesperpixel + 2); samples = fz_malloc(tiff->ctx, stride * tiff->imagelength); for (y = 0; y < tiff->imagelength; y++) { src = tiff->samples + (unsigned int)(tiff->stride * y); dst = samples + (unsigned int)(stride * y); for (x = 0; x < tiff->imagewidth; x++) { if (tiff->extrasamples) { int c = getcomp(src, x * 2, tiff->bitspersample); int a = getcomp(src, x * 2 + 1, tiff->bitspersample); *dst++ = tiff->colormap[c + 0] >> 8; *dst++ = tiff->colormap[c + maxval] >> 8; *dst++ = tiff->colormap[c + maxval * 2] >> 8; *dst++ = a << (8 - tiff->bitspersample); } else { int c = getcomp(src, x, tiff->bitspersample); *dst++ = tiff->colormap[c + 0] >> 8; *dst++ = tiff->colormap[c + maxval] >> 8; *dst++ = tiff->colormap[c + maxval * 2] >> 8; } } } tiff->samplesperpixel += 2; tiff->bitspersample = 8; tiff->stride = stride; fz_free(tiff->ctx, tiff->samples); tiff->samples = samples; } static void fz_decode_tiff_strips(struct tiff *tiff) { fz_stream *stm; /* switch on compression to create a filter */ /* feed each strip to the filter */ /* read out the data and pack the samples into a pixmap */ /* type 32773 / packbits -- nothing special (same row-padding as PDF) */ /* type 2 / ccitt rle -- no EOL, no RTC, rows are byte-aligned */ /* type 3 and 4 / g3 and g4 -- each strip starts new section */ /* type 5 / lzw -- each strip is handled separately */ unsigned char *wp; unsigned row; unsigned strip; unsigned i; if (!tiff->rowsperstrip || !tiff->stripoffsets || !tiff->stripbytecounts) fz_throw(tiff->ctx, FZ_ERROR_GENERIC, "no image data in tiff; maybe it is tiled"); if (tiff->stripoffsetslen < (tiff->imagelength - 1) / tiff->rowsperstrip + 1 || tiff->stripbytecountslen < (tiff->imagelength - 1) / tiff->rowsperstrip + 1) fz_throw(tiff->ctx, FZ_ERROR_GENERIC, "insufficient strip offset data"); if (tiff->planar != 1) fz_throw(tiff->ctx, FZ_ERROR_GENERIC, "image data is not in chunky format"); tiff->stride = (tiff->imagewidth * tiff->samplesperpixel * tiff->bitspersample + 7) / 8; switch (tiff->photometric) { case 0: /* WhiteIsZero -- inverted */ tiff->colorspace = fz_device_gray(tiff->ctx); break; case 1: /* BlackIsZero */ tiff->colorspace = fz_device_gray(tiff->ctx); break; case 2: /* RGB */ tiff->colorspace = fz_device_rgb(tiff->ctx); break; case 3: /* RGBPal */ tiff->colorspace = fz_device_rgb(tiff->ctx); break; case 5: /* CMYK */ tiff->colorspace = fz_device_cmyk(tiff->ctx); break; case 6: /* YCbCr */ /* it's probably a jpeg ... we let jpeg convert to rgb */ tiff->colorspace = fz_device_rgb(tiff->ctx); break; default: fz_throw(tiff->ctx, FZ_ERROR_GENERIC, "unknown photometric: %d", tiff->photometric); } switch (tiff->resolutionunit) { case 2: /* no unit conversion needed */ break; case 3: tiff->xresolution = tiff->xresolution * 254 / 100; tiff->yresolution = tiff->yresolution * 254 / 100; break; default: tiff->xresolution = 96; tiff->yresolution = 96; break; } /* Note xres and yres could be 0 even if unit was set. If so default to 96dpi. */ if (tiff->xresolution == 0 || tiff->yresolution == 0) { tiff->xresolution = 96; tiff->yresolution = 96; } tiff->samples = fz_malloc_array(tiff->ctx, tiff->imagelength, tiff->stride); memset(tiff->samples, 0x55, tiff->imagelength * tiff->stride); wp = tiff->samples; strip = 0; for (row = 0; row < tiff->imagelength; row += tiff->rowsperstrip) { unsigned offset = tiff->stripoffsets[strip]; unsigned rlen = tiff->stripbytecounts[strip]; unsigned wlen = tiff->stride * tiff->rowsperstrip; unsigned char *rp = tiff->bp + offset; if (wp + wlen > tiff->samples + (unsigned int)(tiff->stride * tiff->imagelength)) wlen = tiff->samples + (unsigned int)(tiff->stride * tiff->imagelength) - wp; if (rp + rlen > tiff->ep) fz_throw(tiff->ctx, FZ_ERROR_GENERIC, "strip extends beyond the end of the file"); /* the bits are in un-natural order */ if (tiff->fillorder == 2) for (i = 0; i < rlen; i++) rp[i] = bitrev[rp[i]]; /* the strip decoders will close this */ stm = fz_open_memory(tiff->ctx, rp, rlen); switch (tiff->compression) { case 1: fz_decode_tiff_uncompressed(tiff, stm, wp, wlen); break; case 2: fz_decode_tiff_fax(tiff, 2, stm, wp, wlen); break; case 3: fz_decode_tiff_fax(tiff, 3, stm, wp, wlen); break; case 4: fz_decode_tiff_fax(tiff, 4, stm, wp, wlen); break; case 5: fz_decode_tiff_lzw(tiff, stm, wp, wlen); break; case 6: fz_warn(tiff->ctx, "deprecated JPEG in TIFF compression not fully supported"); /* fall through */ case 7: fz_decode_tiff_jpeg(tiff, stm, wp, wlen); break; case 8: fz_decode_tiff_flate(tiff, stm, wp, wlen); break; case 32773: fz_decode_tiff_packbits(tiff, stm, wp, wlen); break; default: fz_throw(tiff->ctx, FZ_ERROR_GENERIC, "unknown TIFF compression: %d", tiff->compression); } /* scramble the bits back into original order */ if (tiff->fillorder == 2) for (i = 0; i < rlen; i++) rp[i] = bitrev[rp[i]]; wp += tiff->stride * tiff->rowsperstrip; strip ++; } /* Predictor (only for LZW and Flate) */ if ((tiff->compression == 5 || tiff->compression == 8) && tiff->predictor == 2) { unsigned char *p = tiff->samples; for (i = 0; i < tiff->imagelength; i++) { fz_unpredict_tiff(p, tiff->imagewidth, tiff->samplesperpixel, tiff->bitspersample); p += tiff->stride; } } /* RGBPal */ if (tiff->photometric == 3 && tiff->colormap) fz_expand_tiff_colormap(tiff); /* WhiteIsZero .. invert */ if (tiff->photometric == 0) { unsigned char *p = tiff->samples; for (i = 0; i < tiff->imagelength; i++) { fz_invert_tiff(p, tiff->imagewidth, tiff->samplesperpixel, tiff->bitspersample, tiff->extrasamples); p += tiff->stride; } } /* Premultiplied transparency */ if (tiff->extrasamples == 1) { /* In GhostXPS we undo the premultiplication here; muxps holds * all our images premultiplied by default, so nothing to do. */ } /* Non-premultiplied transparency */ if (tiff->extrasamples == 2) { /* Premultiplied files are corrected for elsewhere */ } } static inline int readbyte(struct tiff *tiff) { if (tiff->rp < tiff->ep) return *tiff->rp++; return EOF; } static inline unsigned readshort(struct tiff *tiff) { unsigned a = readbyte(tiff); unsigned b = readbyte(tiff); if (tiff->order == TII) return (b << 8) | a; return (a << 8) | b; } static inline unsigned readlong(struct tiff *tiff) { unsigned a = readbyte(tiff); unsigned b = readbyte(tiff); unsigned c = readbyte(tiff); unsigned d = readbyte(tiff); if (tiff->order == TII) return (d << 24) | (c << 16) | (b << 8) | a; return (a << 24) | (b << 16) | (c << 8) | d; } static void fz_read_tiff_bytes(unsigned char *p, struct tiff *tiff, unsigned ofs, unsigned n) { tiff->rp = tiff->bp + ofs; if (tiff->rp > tiff->ep) tiff->rp = tiff->bp; while (n--) *p++ = readbyte(tiff); } static void fz_read_tiff_tag_value(unsigned *p, struct tiff *tiff, unsigned type, unsigned ofs, unsigned n) { tiff->rp = tiff->bp + ofs; if (tiff->rp > tiff->ep) tiff->rp = tiff->bp; while (n--) { switch (type) { case TRATIONAL: *p = readlong(tiff); *p = *p / readlong(tiff); p ++; break; case TBYTE: *p++ = readbyte(tiff); break; case TSHORT: *p++ = readshort(tiff); break; case TLONG: *p++ = readlong(tiff); break; default: *p++ = 0; break; } } } static void fz_read_tiff_tag(struct tiff *tiff, unsigned offset) { unsigned tag; unsigned type; unsigned count; unsigned value; tiff->rp = tiff->bp + offset; tag = readshort(tiff); type = readshort(tiff); count = readlong(tiff); if ((type == TBYTE && count <= 4) || (type == TSHORT && count <= 2) || (type == TLONG && count <= 1)) value = tiff->rp - tiff->bp; else value = readlong(tiff); switch (tag) { case NewSubfileType: fz_read_tiff_tag_value(&tiff->subfiletype, tiff, type, value, 1); break; case ImageWidth: fz_read_tiff_tag_value(&tiff->imagewidth, tiff, type, value, 1); break; case ImageLength: fz_read_tiff_tag_value(&tiff->imagelength, tiff, type, value, 1); break; case BitsPerSample: fz_read_tiff_tag_value(&tiff->bitspersample, tiff, type, value, 1); break; case Compression: fz_read_tiff_tag_value(&tiff->compression, tiff, type, value, 1); break; case PhotometricInterpretation: fz_read_tiff_tag_value(&tiff->photometric, tiff, type, value, 1); break; case FillOrder: fz_read_tiff_tag_value(&tiff->fillorder, tiff, type, value, 1); break; case SamplesPerPixel: fz_read_tiff_tag_value(&tiff->samplesperpixel, tiff, type, value, 1); break; case RowsPerStrip: fz_read_tiff_tag_value(&tiff->rowsperstrip, tiff, type, value, 1); break; case XResolution: fz_read_tiff_tag_value(&tiff->xresolution, tiff, type, value, 1); break; case YResolution: fz_read_tiff_tag_value(&tiff->yresolution, tiff, type, value, 1); break; case PlanarConfiguration: fz_read_tiff_tag_value(&tiff->planar, tiff, type, value, 1); break; case T4Options: fz_read_tiff_tag_value(&tiff->g3opts, tiff, type, value, 1); break; case T6Options: fz_read_tiff_tag_value(&tiff->g4opts, tiff, type, value, 1); break; case Predictor: fz_read_tiff_tag_value(&tiff->predictor, tiff, type, value, 1); break; case ResolutionUnit: fz_read_tiff_tag_value(&tiff->resolutionunit, tiff, type, value, 1); break; case YCbCrSubSampling: fz_read_tiff_tag_value(tiff->ycbcrsubsamp, tiff, type, value, 2); break; case ExtraSamples: fz_read_tiff_tag_value(&tiff->extrasamples, tiff, type, value, 1); break; case ICCProfile: tiff->profile = fz_malloc(tiff->ctx, count); /* ICC profile data type is set to UNDEFINED. * TBYTE reading not correct in fz_read_tiff_tag_value */ fz_read_tiff_bytes(tiff->profile, tiff, value, count); tiff->profilesize = count; break; case JPEGTables: tiff->jpegtables = tiff->bp + value; tiff->jpegtableslen = count; break; case StripOffsets: tiff->stripoffsets = fz_malloc_array(tiff->ctx, count, sizeof(unsigned)); fz_read_tiff_tag_value(tiff->stripoffsets, tiff, type, value, count); tiff->stripoffsetslen = count; break; case StripByteCounts: tiff->stripbytecounts = fz_malloc_array(tiff->ctx, count, sizeof(unsigned)); fz_read_tiff_tag_value(tiff->stripbytecounts, tiff, type, value, count); tiff->stripbytecountslen = count; break; case ColorMap: tiff->colormap = fz_malloc_array(tiff->ctx, count, sizeof(unsigned)); fz_read_tiff_tag_value(tiff->colormap, tiff, type, value, count); tiff->colormaplen = count; break; case TileWidth: case TileLength: case TileOffsets: case TileByteCounts: fz_throw(tiff->ctx, FZ_ERROR_GENERIC, "tiled tiffs not supported"); default: /* fz_warn(tiff->ctx, "unknown tag: %d t=%d n=%d", tag, type, count); */ break; } } static void fz_swap_tiff_byte_order(unsigned char *buf, int n) { int i, t; for (i = 0; i < n; i++) { t = buf[i * 2 + 0]; buf[i * 2 + 0] = buf[i * 2 + 1]; buf[i * 2 + 1] = t; } } static void fz_decode_tiff_header(fz_context *ctx, struct tiff *tiff, unsigned char *buf, int len) { unsigned version; memset(tiff, 0, sizeof(struct tiff)); tiff->ctx = ctx; tiff->bp = buf; tiff->rp = buf; tiff->ep = buf + len; /* tag defaults, where applicable */ tiff->bitspersample = 1; tiff->compression = 1; tiff->samplesperpixel = 1; tiff->resolutionunit = 2; tiff->rowsperstrip = 0xFFFFFFFF; tiff->fillorder = 1; tiff->planar = 1; tiff->subfiletype = 0; tiff->predictor = 1; tiff->ycbcrsubsamp[0] = 2; tiff->ycbcrsubsamp[1] = 2; /* * Read IFH */ /* get byte order marker */ tiff->order = TII; tiff->order = readshort(tiff); if (tiff->order != TII && tiff->order != TMM) fz_throw(tiff->ctx, FZ_ERROR_GENERIC, "not a TIFF file, wrong magic marker"); /* check version */ version = readshort(tiff); if (version != 42) fz_throw(tiff->ctx, FZ_ERROR_GENERIC, "not a TIFF file, wrong version marker"); /* get offset of IFD */ tiff->ifd_offset = readlong(tiff); } static unsigned fz_next_ifd(fz_context *ctx, struct tiff *tiff, unsigned offset) { unsigned count; tiff->rp = tiff->bp + offset; if (tiff->rp <= tiff->bp || tiff->rp > tiff->ep) fz_throw(tiff->ctx, FZ_ERROR_GENERIC, "invalid IFD offset %u", offset); count = readshort(tiff); if (count * 12 > (unsigned)(tiff->ep - tiff->rp)) fz_throw(tiff->ctx, FZ_ERROR_GENERIC, "overlarge IFD entry count %u", count); tiff->rp += count * 12; offset = readlong(tiff); return offset; } static void fz_seek_ifd(fz_context *ctx, struct tiff *tiff, int subimage) { unsigned offset = tiff->ifd_offset; while (subimage--) { offset = fz_next_ifd(ctx, tiff, offset); if (offset == 0) fz_throw(tiff->ctx, FZ_ERROR_GENERIC, "subimage index %i out of range", subimage); } tiff->rp = tiff->bp + offset; if (tiff->rp < tiff->bp || tiff->rp > tiff->ep) fz_throw(tiff->ctx, FZ_ERROR_GENERIC, "invalid IFD offset %u", tiff->ifd_offset); } static void fz_decode_tiff_ifd(fz_context *ctx, struct tiff *tiff) { unsigned offset; unsigned count; unsigned i; offset = tiff->rp - tiff->bp; count = readshort(tiff); if (count * 12 > (unsigned)(tiff->ep - tiff->rp)) fz_throw(tiff->ctx, FZ_ERROR_GENERIC, "overlarge IFD entry count %u", count); offset += 2; for (i = 0; i < count; i++) { fz_read_tiff_tag(tiff, offset); offset += 12; } } fz_pixmap * fz_load_tiff_subimage(fz_context *ctx, unsigned char *buf, int len, int subimage) { fz_pixmap *image; struct tiff tiff = { 0 }; fz_try(ctx) { fz_decode_tiff_header(ctx, &tiff, buf, len); fz_seek_ifd(ctx, &tiff, subimage); fz_decode_tiff_ifd(ctx, &tiff); /* Decode the image strips */ if (tiff.rowsperstrip > tiff.imagelength) tiff.rowsperstrip = tiff.imagelength; fz_decode_tiff_strips(&tiff); /* Byte swap 16-bit images to big endian if necessary */ if (tiff.bitspersample == 16) if (tiff.order == TII) fz_swap_tiff_byte_order(tiff.samples, tiff.imagewidth * tiff.imagelength * tiff.samplesperpixel); /* Expand into fz_pixmap struct */ image = fz_new_pixmap(tiff.ctx, tiff.colorspace, tiff.imagewidth, tiff.imagelength); image->xres = tiff.xresolution; image->yres = tiff.yresolution; fz_unpack_tile(image, tiff.samples, tiff.samplesperpixel, tiff.bitspersample, tiff.stride, 0); /* We should only do this on non-pre-multiplied images, but files in the wild are bad */ if (tiff.extrasamples /* == 2 */) { /* CMYK is a subtractive colorspace, we want additive for premul alpha */ if (image->n == 5) { fz_pixmap *rgb = fz_new_pixmap(tiff.ctx, fz_device_rgb(ctx), image->w, image->h); fz_convert_pixmap(tiff.ctx, rgb, image); rgb->xres = image->xres; rgb->yres = image->yres; fz_drop_pixmap(ctx, image); image = rgb; } fz_premultiply_pixmap(ctx, image); } } fz_always(ctx) { /* Clean up scratch memory */ if (tiff.colormap) fz_free(ctx, tiff.colormap); if (tiff.stripoffsets) fz_free(ctx, tiff.stripoffsets); if (tiff.stripbytecounts) fz_free(ctx, tiff.stripbytecounts); if (tiff.samples) fz_free(ctx, tiff.samples); if (tiff.profile) fz_free(ctx, tiff.profile); } fz_catch(ctx) { fz_rethrow_message(ctx, "out of memory loading tiff"); } return image; } fz_pixmap * fz_load_tiff(fz_context *ctx, unsigned char *buf, int len) { return fz_load_tiff_subimage(ctx, buf, len, 0); } void fz_load_tiff_info_subimage(fz_context *ctx, unsigned char *buf, int len, int *wp, int *hp, int *xresp, int *yresp, fz_colorspace **cspacep, int subimage) { struct tiff tiff = { 0 }; fz_try(ctx) { fz_decode_tiff_header(ctx, &tiff, buf, len); fz_seek_ifd(ctx, &tiff, subimage); fz_decode_tiff_ifd(ctx, &tiff); *wp = tiff.imagewidth; *hp = tiff.imagelength; *xresp = tiff.xresolution; *yresp = tiff.yresolution; *cspacep = tiff.colorspace; } fz_always(ctx) { /* Clean up scratch memory */ if (tiff.colormap) fz_free(ctx, tiff.colormap); if (tiff.stripoffsets) fz_free(ctx, tiff.stripoffsets); if (tiff.stripbytecounts) fz_free(ctx, tiff.stripbytecounts); if (tiff.samples) fz_free(ctx, tiff.samples); if (tiff.profile) fz_free(ctx, tiff.profile); } fz_catch(ctx) { fz_rethrow_message(ctx, "out of memory loading tiff"); } } void fz_load_tiff_info(fz_context *ctx, unsigned char *buf, int len, int *wp, int *hp, int *xresp, int *yresp, fz_colorspace **cspacep) { fz_load_tiff_info_subimage(ctx, buf, len, wp, hp, xresp, yresp, cspacep, 0); } int fz_load_tiff_subimage_count(fz_context *ctx, unsigned char *buf, int len) { unsigned offset; unsigned subimage_count = 0; struct tiff tiff = { 0 }; fz_try(ctx) { fz_decode_tiff_header(ctx, &tiff, buf, len); offset = tiff.ifd_offset; do { subimage_count++; offset = fz_next_ifd(ctx, &tiff, offset); } while (offset != 0); } fz_catch(ctx) { fz_rethrow_message(ctx, "error while counting subimages in tiff"); } return subimage_count; }