thumbnail.c

/*
 * Copyright (c) 1994-1997 Sam Leffler
 * Copyright (c) 1994-1997 Silicon Graphics, Inc.
 *
 * Permission to use, copy, modify, distribute, and sell this software and
 * its documentation for any purpose is hereby granted without fee, provided
 * that (i) the above copyright notices and this permission notice appear in
 * all copies of the software and related documentation, and (ii) the names of
 * Sam Leffler and Silicon Graphics may not be used in any advertising or
 * publicity relating to the software without the specific, prior written
 * permission of Sam Leffler and Silicon Graphics.
 *
 * THE SOFTWARE IS PROVIDED "AS-IS" AND WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS, IMPLIED OR OTHERWISE, INCLUDING WITHOUT LIMITATION, ANY
 * WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
 *
 * IN NO EVENT SHALL SAM LEFFLER OR SILICON GRAPHICS BE LIABLE FOR
 * ANY SPECIAL, INCIDENTAL, INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY KIND,
 * OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
 * WHETHER OR NOT ADVISED OF THE POSSIBILITY OF DAMAGE, AND ON ANY THEORY OF
 * LIABILITY, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
 * OF THIS SOFTWARE.
 */

#include "tiff_tools_internal.h"

#include <math.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif

#include <tiffio.h>

#ifndef EXIT_SUCCESS
#define EXIT_SUCCESS 0
#endif
#ifndef EXIT_FAILURE
#define EXIT_FAILURE 1
#endif

#define streq(a, b) (strcmp(a, b) == 0)

#ifndef TIFFhowmany8
#define TIFFhowmany8(x)                                                        \
    (((x)&0x07) ? ((uint32_t)(x) >> 3) + 1 : (uint32_t)(x) >> 3)
#endif

typedef enum
{
    EXP50,
    EXP60,
    EXP70,
    EXP80,
    EXP90,
    EXP,
    LINEAR
} Contrast;

static uint32_t tnw = 216;         /* thumbnail width */
static uint32_t tnh = 274;         /* thumbnail height */
static Contrast contrast = LINEAR; /* current contrast */
static uint8_t *thumbnail;

static int cpIFD(TIFF *, TIFF *);
static int generateThumbnail(TIFF *, TIFF *);
static void initScale();
static void usage(int code);

#if !HAVE_DECL_OPTARG
extern char *optarg;
extern int optind;
#endif

int main(int argc, char *argv[])
{
    TIFF *in;
    TIFF *out;
    int c;

    while ((c = getopt(argc, argv, "w:h:c:")) != -1)
    {
        switch (c)
        {
            case 'w':
                tnw = strtoul(optarg, NULL, 0);
                break;
            case 'h':
                tnh = strtoul(optarg, NULL, 0);
                break;
            case 'c':
                contrast = streq(optarg, "exp50")    ? EXP50
                           : streq(optarg, "exp60")  ? EXP60
                           : streq(optarg, "exp70")  ? EXP70
                           : streq(optarg, "exp80")  ? EXP80
                           : streq(optarg, "exp90")  ? EXP90
                           : streq(optarg, "exp")    ? EXP
                           : streq(optarg, "linear") ? LINEAR
                                                     : EXP;
                break;
            default:
                usage(EXIT_FAILURE);
        }
    }
    if (argc - optind != 2)
        usage(EXIT_FAILURE);

    out = TIFFOpen(argv[optind + 1], "w");
    if (out == NULL)
        return 2;
    in = TIFFOpen(argv[optind], "r");
    if (in == NULL)
        return 2;

    thumbnail = (uint8_t *)_TIFFmalloc(tnw * tnh);
    if (!thumbnail)
    {
        TIFFError(TIFFFileName(in),
                  "Can't allocate space for thumbnail buffer.");
        return EXIT_FAILURE;
    }

    if (in != NULL)
    {
        initScale();
        do
        {
            if (!generateThumbnail(in, out))
                goto bad;
            if (!cpIFD(in, out) || !TIFFWriteDirectory(out))
                goto bad;
        } while (TIFFReadDirectory(in));
        (void)TIFFClose(in);
    }
    (void)TIFFClose(out);
    return EXIT_SUCCESS;
bad:
    (void)TIFFClose(out);
    return EXIT_FAILURE;
}

#define CopyField(tag, v)                                                      \
    if (TIFFGetField(in, tag, &v))                                             \
    TIFFSetField(out, tag, v)
#define CopyField2(tag, v1, v2)                                                \
    if (TIFFGetField(in, tag, &v1, &v2))                                       \
    TIFFSetField(out, tag, v1, v2)
#define CopyField3(tag, v1, v2, v3)                                            \
    if (TIFFGetField(in, tag, &v1, &v2, &v3))                                  \
    TIFFSetField(out, tag, v1, v2, v3)
#define CopyField4(tag, v1, v2, v3, v4)                                        \
    if (TIFFGetField(in, tag, &v1, &v2, &v3, &v4))                             \
    TIFFSetField(out, tag, v1, v2, v3, v4)

static void cpTag(TIFF *in, TIFF *out, uint16_t tag, uint16_t count,
                  TIFFDataType type)
{
    switch (type)
    {
        case TIFF_SHORT:
            if (count == 1)
            {
                uint16_t shortv;
                CopyField(tag, shortv);
            }
            else if (count == 2)
            {
                uint16_t shortv1, shortv2;
                CopyField2(tag, shortv1, shortv2);
            }
            else if (count == 4)
            {
                uint16_t *tr, *tg, *tb, *ta;
                CopyField4(tag, tr, tg, tb, ta);
            }
            else if (count == (uint16_t)-1)
            {
                uint16_t shortv1;
                uint16_t *shortav;
                CopyField2(tag, shortv1, shortav);
            }
            break;
        case TIFF_LONG:
        {
            uint32_t longv;
            CopyField(tag, longv);
        }
        break;
        case TIFF_LONG8:
        {
            uint64_t longv8;
            CopyField(tag, longv8);
        }
        break;
        case TIFF_SLONG8:
        {
            int64_t longv8;
            CopyField(tag, longv8);
        }
        break;
        case TIFF_RATIONAL:
            if (count == 1)
            {
                float floatv;
                CopyField(tag, floatv);
            }
            else if (count == (uint16_t)-1)
            {
                float *floatav;
                CopyField(tag, floatav);
            }
            break;
        case TIFF_ASCII:
        {
            char *stringv;
            CopyField(tag, stringv);
        }
        break;
        case TIFF_DOUBLE:
            if (count == 1)
            {
                double doublev;
                CopyField(tag, doublev);
            }
            else if (count == (uint16_t)-1)
            {
                double *doubleav;
                CopyField(tag, doubleav);
            }
            break;
        case TIFF_IFD8:
        {
            toff_t ifd8;
            CopyField(tag, ifd8);
        }
        break;
        default:
            TIFFError(TIFFFileName(in),
                      "Data type %d is not supported, tag %d skipped.", tag,
                      type);
    }
}

#undef CopyField4
#undef CopyField3
#undef CopyField2
#undef CopyField

static const struct cpTag
{
    uint16_t tag;
    uint16_t count;
    TIFFDataType type;
} tags[] = {
    {TIFFTAG_IMAGEWIDTH, 1, TIFF_LONG},
    {TIFFTAG_IMAGELENGTH, 1, TIFF_LONG},
    {TIFFTAG_BITSPERSAMPLE, 1, TIFF_SHORT},
    {TIFFTAG_COMPRESSION, 1, TIFF_SHORT},
    {TIFFTAG_FILLORDER, 1, TIFF_SHORT},
    {TIFFTAG_SAMPLESPERPIXEL, 1, TIFF_SHORT},
    {TIFFTAG_ROWSPERSTRIP, 1, TIFF_LONG},
    {TIFFTAG_PLANARCONFIG, 1, TIFF_SHORT},
    {TIFFTAG_GROUP3OPTIONS, 1, TIFF_LONG},
    {TIFFTAG_SUBFILETYPE, 1, TIFF_LONG},
    {TIFFTAG_PHOTOMETRIC, 1, TIFF_SHORT},
    {TIFFTAG_THRESHHOLDING, 1, TIFF_SHORT},
    {TIFFTAG_DOCUMENTNAME, 1, TIFF_ASCII},
    {TIFFTAG_IMAGEDESCRIPTION, 1, TIFF_ASCII},
    {TIFFTAG_MAKE, 1, TIFF_ASCII},
    {TIFFTAG_MODEL, 1, TIFF_ASCII},
    {TIFFTAG_ORIENTATION, 1, TIFF_SHORT},
    {TIFFTAG_MINSAMPLEVALUE, 1, TIFF_SHORT},
    {TIFFTAG_MAXSAMPLEVALUE, 1, TIFF_SHORT},
    {TIFFTAG_XRESOLUTION, 1, TIFF_RATIONAL},
    {TIFFTAG_YRESOLUTION, 1, TIFF_RATIONAL},
    {TIFFTAG_PAGENAME, 1, TIFF_ASCII},
    {TIFFTAG_XPOSITION, 1, TIFF_RATIONAL},
    {TIFFTAG_YPOSITION, 1, TIFF_RATIONAL},
    {TIFFTAG_GROUP4OPTIONS, 1, TIFF_LONG},
    {TIFFTAG_RESOLUTIONUNIT, 1, TIFF_SHORT},
    {TIFFTAG_PAGENUMBER, 2, TIFF_SHORT},
    {TIFFTAG_SOFTWARE, 1, TIFF_ASCII},
    {TIFFTAG_DATETIME, 1, TIFF_ASCII},
    {TIFFTAG_ARTIST, 1, TIFF_ASCII},
    {TIFFTAG_HOSTCOMPUTER, 1, TIFF_ASCII},
    {TIFFTAG_WHITEPOINT, 2, TIFF_RATIONAL},
    {TIFFTAG_PRIMARYCHROMATICITIES, (uint16_t)-1, TIFF_RATIONAL},
    {TIFFTAG_HALFTONEHINTS, 2, TIFF_SHORT},
    {TIFFTAG_BADFAXLINES, 1, TIFF_LONG},
    {TIFFTAG_CLEANFAXDATA, 1, TIFF_SHORT},
    {TIFFTAG_CONSECUTIVEBADFAXLINES, 1, TIFF_LONG},
    {TIFFTAG_INKSET, 1, TIFF_SHORT},
    /*{ TIFFTAG_INKNAMES,			1, TIFF_ASCII },*/ /* Needs much
                                                                      more
                                                                      complicated
                                                                      logic. See
                                                                      tiffcp */
    {TIFFTAG_DOTRANGE, 2, TIFF_SHORT},
    {TIFFTAG_TARGETPRINTER, 1, TIFF_ASCII},
    {TIFFTAG_SAMPLEFORMAT, 1, TIFF_SHORT},
    {TIFFTAG_YCBCRCOEFFICIENTS, (uint16_t)-1, TIFF_RATIONAL},
    {TIFFTAG_YCBCRSUBSAMPLING, 2, TIFF_SHORT},
    {TIFFTAG_YCBCRPOSITIONING, 1, TIFF_SHORT},
    {TIFFTAG_REFERENCEBLACKWHITE, (uint16_t)-1, TIFF_RATIONAL},
    {TIFFTAG_EXTRASAMPLES, (uint16_t)-1, TIFF_SHORT},
};
#define NTAGS (sizeof(tags) / sizeof(tags[0]))

static void cpTags(TIFF *in, TIFF *out)
{
    const struct cpTag *p;
    for (p = tags; p < &tags[NTAGS]; p++)
    {
        /* Horrible: but TIFFGetField() expects 2 arguments to be passed */
        /* if we request a tag that is defined in a codec, but that codec */
        /* isn't used */
        if (p->tag == TIFFTAG_GROUP3OPTIONS)
        {
            uint16_t compression;
            if (!TIFFGetField(in, TIFFTAG_COMPRESSION, &compression) ||
                compression != COMPRESSION_CCITTFAX3)
                continue;
        }
        if (p->tag == TIFFTAG_GROUP4OPTIONS)
        {
            uint16_t compression;
            if (!TIFFGetField(in, TIFFTAG_COMPRESSION, &compression) ||
                compression != COMPRESSION_CCITTFAX4)
                continue;
        }
        cpTag(in, out, p->tag, p->count, p->type);
    }
}
#undef NTAGS

static int cpStrips(TIFF *in, TIFF *out)
{
    tsize_t bufsize = TIFFStripSize(in);
    unsigned char *buf = (unsigned char *)_TIFFmalloc(bufsize);

    if (buf)
    {
        tstrip_t s, ns = TIFFNumberOfStrips(in);
        uint64_t *bytecounts;

        TIFFGetField(in, TIFFTAG_STRIPBYTECOUNTS, &bytecounts);
        for (s = 0; s < ns; s++)
        {
            if (bytecounts[s] > (uint64_t)bufsize)
            {
                buf =
                    (unsigned char *)_TIFFrealloc(buf, (tmsize_t)bytecounts[s]);
                if (!buf)
                    goto bad;
                bufsize = (tmsize_t)bytecounts[s];
            }
            if (TIFFReadRawStrip(in, s, buf, (tmsize_t)bytecounts[s]) < 0 ||
                TIFFWriteRawStrip(out, s, buf, (tmsize_t)bytecounts[s]) < 0)
            {
                _TIFFfree(buf);
                return 0;
            }
        }
        _TIFFfree(buf);
        return 1;
    }

bad:
    TIFFError(TIFFFileName(in), "Can't allocate space for strip buffer.");
    return 0;
}

static int cpTiles(TIFF *in, TIFF *out)
{
    tsize_t bufsize = TIFFTileSize(in);
    unsigned char *buf = (unsigned char *)_TIFFmalloc(bufsize);

    if (buf)
    {
        ttile_t t, nt = TIFFNumberOfTiles(in);
        uint64_t *bytecounts;

        TIFFGetField(in, TIFFTAG_TILEBYTECOUNTS, &bytecounts);
        for (t = 0; t < nt; t++)
        {
            if (bytecounts[t] > (uint64_t)bufsize)
            {
                buf =
                    (unsigned char *)_TIFFrealloc(buf, (tmsize_t)bytecounts[t]);
                if (!buf)
                    goto bad;
                bufsize = (tmsize_t)bytecounts[t];
            }
            if (TIFFReadRawTile(in, t, buf, (tmsize_t)bytecounts[t]) < 0 ||
                TIFFWriteRawTile(out, t, buf, (tmsize_t)bytecounts[t]) < 0)
            {
                _TIFFfree(buf);
                return 0;
            }
        }
        _TIFFfree(buf);
        return 1;
    }

bad:
    TIFFError(TIFFFileName(in), "Can't allocate space for tile buffer.");
    return (0);
}

static int cpIFD(TIFF *in, TIFF *out)
{
    cpTags(in, out);
    if (TIFFIsTiled(in))
    {
        if (!cpTiles(in, out))
            return (0);
    }
    else
    {
        if (!cpStrips(in, out))
            return (0);
    }
    return (1);
}

static uint16_t photometric;  /* current photometric of raster */
static uint16_t filterWidth;  /* filter width in pixels */
static uint32_t stepSrcWidth; /* src image stepping width */
static uint32_t stepDstWidth; /* dest stepping width */
static uint8_t *src0;         /* horizontal bit stepping (start) */
static uint8_t *src1;         /* horizontal bit stepping (middle) */
static uint8_t *src2;         /* horizontal bit stepping (end) */
static uint32_t *rowoff;      /* row offset for stepping */
static uint8_t cmap[256];     /* colormap indexes */
static uint8_t bits[256];     /* count of bits set */

static void setupBitsTables()
{
    int i;
    for (i = 0; i < 256; i++)
    {
        int n = 0;
        if (i & 0x01)
            n++;
        if (i & 0x02)
            n++;
        if (i & 0x04)
            n++;
        if (i & 0x08)
            n++;
        if (i & 0x10)
            n++;
        if (i & 0x20)
            n++;
        if (i & 0x40)
            n++;
        if (i & 0x80)
            n++;
        bits[i] = n;
    }
}

static int clamp(float v, int low, int high)
{
    return (v < low ? low : v > high ? high : (int)v);
}

#ifndef M_E
#define M_E 2.7182818284590452354
#endif

static void expFill(float pct[], uint32_t p, uint32_t n)
{
    uint32_t i;
    uint32_t c = (p * n) / 100;
    for (i = 1; i < c; i++)
        pct[i] = (float)(1 - exp(i / ((double)(n - 1))) / M_E);
    for (; i < n; i++)
        pct[i] = 0.;
}

static void setupCmap()
{
    float pct[256]; /* known to be large enough */
    uint32_t i;
    pct[0] = 1; /* force white */
    switch (contrast)
    {
        case EXP50:
            expFill(pct, 50, 256);
            break;
        case EXP60:
            expFill(pct, 60, 256);
            break;
        case EXP70:
            expFill(pct, 70, 256);
            break;
        case EXP80:
            expFill(pct, 80, 256);
            break;
        case EXP90:
            expFill(pct, 90, 256);
            break;
        case EXP:
            expFill(pct, 100, 256);
            break;
        case LINEAR:
            for (i = 1; i < 256; i++)
                pct[i] = 1 - ((float)i) / (256 - 1);
            break;
    }
    switch (photometric)
    {
        case PHOTOMETRIC_MINISWHITE:
            for (i = 0; i < 256; i++)
                cmap[i] = clamp(255 * pct[(256 - 1) - i], 0, 255);
            break;
        case PHOTOMETRIC_MINISBLACK:
            for (i = 0; i < 256; i++)
                cmap[i] = clamp(255 * pct[i], 0, 255);
            break;
    }
}

static void initScale()
{
    src0 = (uint8_t *)_TIFFmalloc(sizeof(uint8_t) * tnw);
    src1 = (uint8_t *)_TIFFmalloc(sizeof(uint8_t) * tnw);
    src2 = (uint8_t *)_TIFFmalloc(sizeof(uint8_t) * tnw);
    rowoff = (uint32_t *)_TIFFmalloc(sizeof(uint32_t) * tnw);
    filterWidth = 0;
    stepDstWidth = stepSrcWidth = 0;
    setupBitsTables();
}

/*
 * Calculate the horizontal accumulation parameteres
 * according to the widths of the src and dst images.
 */
static void setupStepTables(uint32_t sw)
{
    if (stepSrcWidth != sw || stepDstWidth != tnw)
    {
        int step = sw;
        int limit = tnw;
        int err = 0;
        uint32_t sx = 0;
        uint32_t x;
        int fw;
        uint8_t b;
        for (x = 0; x < tnw; x++)
        {
            uint32_t sx0 = sx;
            err += step;
            while (err >= limit)
            {
                err -= limit;
                sx++;
            }
            rowoff[x] = sx0 >> 3;
            fw = sx - sx0; /* width */
            b = (fw < 8) ? 0xff << (8 - fw) : 0xff;
            src0[x] = b >> (sx0 & 7);
            fw -= 8 - (sx0 & 7);
            if (fw < 0)
                fw = 0;
            src1[x] = fw >> 3;
            fw -= (fw >> 3) << 3;
            src2[x] = 0xff << (8 - fw);
        }
        stepSrcWidth = sw;
        stepDstWidth = tnw;
    }
}

static void setrow(uint8_t *row, uint32_t nrows, const uint8_t *rows[])
{
    uint32_t x;
    uint32_t area = nrows * filterWidth;
    for (x = 0; x < tnw; x++)
    {
        uint32_t mask0 = src0[x];
        uint32_t fw = src1[x];
        uint32_t mask1 = src1[x];
        uint32_t off = rowoff[x];
        uint32_t acc = 0;
        uint32_t y, i;
        for (y = 0; y < nrows; y++)
        {
            const uint8_t *src = rows[y] + off;
            acc += bits[*src++ & mask0];
            switch (fw)
            {
                default:
                    for (i = fw; i > 8; i--)
                        acc += bits[*src++];
                    /* fall through... */
                case 8:
                    acc += bits[*src++]; /* fall through */
                case 7:
                    acc += bits[*src++]; /* fall through */
                case 6:
                    acc += bits[*src++]; /* fall through */
                case 5:
                    acc += bits[*src++]; /* fall through */
                case 4:
                    acc += bits[*src++]; /* fall through */
                case 3:
                    acc += bits[*src++]; /* fall through */
                case 2:
                    acc += bits[*src++]; /* fall through */
                case 1:
                    acc += bits[*src++]; /* fall through */
                case 0:
                    break;
            }
            acc += bits[*src & mask1];
        }
        *row++ = cmap[(255 * acc) / area];
    }
}

/*
 * Install the specified image.  The
 * image is resized to fit the display page using
 * a box filter.  The resultant pixels are mapped
 * with a user-selectable contrast curve.
 */
static void setImage1(const uint8_t *br, uint32_t rw, uint32_t rh)
{
    int step = rh;
    int limit = tnh;
    int err = 0;
    int bpr = TIFFhowmany8(rw);
    int sy = 0;
    uint8_t *row = thumbnail;
    uint32_t dy;
    for (dy = 0; dy < tnh; dy++)
    {
        const uint8_t *rows[256];
        uint32_t nrows = 1;
        fprintf(stderr, "bpr=%d, sy=%d, bpr*sy=%d\n", bpr, sy, bpr * sy);
        rows[0] = br + bpr * sy;
        err += step;
        while (err >= limit)
        {
            err -= limit;
            sy++;
            if (err >= limit)
            {
                /* We should perhaps error loudly, but I can't make sense of
                 * that */
                /* code... */
                if (nrows == 256)
                    break;
                rows[nrows++] = br + bpr * sy;
            }
        }
        setrow(row, nrows, rows);
        row += tnw;
    }
}

static void setImage(const uint8_t *br, uint32_t rw, uint32_t rh)
{
    filterWidth = (uint16_t)ceil((double)rw / (double)tnw);
    setupStepTables(rw);
    setImage1(br, rw, rh);
}

static int generateThumbnail(TIFF *in, TIFF *out)
{
    unsigned char *raster;
    unsigned char *rp;
    uint32_t sw, sh, rps;
    uint16_t bps, spp;
    tsize_t rowsize, rastersize;
    tstrip_t s, ns = TIFFNumberOfStrips(in);
    toff_t diroff[1];

    TIFFGetField(in, TIFFTAG_IMAGEWIDTH, &sw);
    TIFFGetField(in, TIFFTAG_IMAGELENGTH, &sh);
    TIFFGetFieldDefaulted(in, TIFFTAG_BITSPERSAMPLE, &bps);
    TIFFGetFieldDefaulted(in, TIFFTAG_SAMPLESPERPIXEL, &spp);
    TIFFGetFieldDefaulted(in, TIFFTAG_ROWSPERSTRIP, &rps);
    if (spp != 1 || bps != 1)
        return 0;
    rowsize = TIFFScanlineSize(in);
    rastersize = sh * rowsize;
    fprintf(stderr, "rastersize=%u\n", (unsigned int)rastersize);
    /* +3 : add a few guard bytes since setrow() can read a bit */
    /* outside buffer */
    raster = (unsigned char *)_TIFFmalloc(rastersize + 3);
    if (!raster)
    {
        TIFFError(TIFFFileName(in), "Can't allocate space for raster buffer.");
        return 0;
    }
    raster[rastersize] = 0;
    raster[rastersize + 1] = 0;
    raster[rastersize + 2] = 0;
    rp = raster;
    for (s = 0; s < ns; s++)
    {
        (void)TIFFReadEncodedStrip(in, s, rp, -1);
        rp += rps * rowsize;
    }
    TIFFGetField(in, TIFFTAG_PHOTOMETRIC, &photometric);
    setupCmap();
    setImage(raster, sw, sh);
    _TIFFfree(raster);

    TIFFSetField(out, TIFFTAG_SUBFILETYPE, FILETYPE_REDUCEDIMAGE);
    TIFFSetField(out, TIFFTAG_IMAGEWIDTH, (uint32_t)tnw);
    TIFFSetField(out, TIFFTAG_IMAGELENGTH, (uint32_t)tnh);
    TIFFSetField(out, TIFFTAG_BITSPERSAMPLE, (uint16_t)8);
    TIFFSetField(out, TIFFTAG_SAMPLESPERPIXEL, (uint16_t)1);
    TIFFSetField(out, TIFFTAG_COMPRESSION, COMPRESSION_PACKBITS);
    TIFFSetField(out, TIFFTAG_PHOTOMETRIC, PHOTOMETRIC_MINISWHITE);
    TIFFSetField(out, TIFFTAG_PLANARCONFIG, PLANARCONFIG_CONTIG);
    TIFFSetField(out, TIFFTAG_ORIENTATION, ORIENTATION_TOPLEFT);
    cpTag(in, out, TIFFTAG_SOFTWARE, (uint16_t)-1, TIFF_ASCII);
    cpTag(in, out, TIFFTAG_IMAGEDESCRIPTION, (uint16_t)-1, TIFF_ASCII);
    cpTag(in, out, TIFFTAG_DATETIME, (uint16_t)-1, TIFF_ASCII);
    cpTag(in, out, TIFFTAG_HOSTCOMPUTER, (uint16_t)-1, TIFF_ASCII);
    diroff[0] = 0UL;
    TIFFSetField(out, TIFFTAG_SUBIFD, 1, diroff);
    return (TIFFWriteEncodedStrip(out, 0, thumbnail, tnw * tnh) != -1 &&
            TIFFWriteDirectory(out) != -1);
}

const char *usage_info[] = {
    "Create a TIFF file with thumbnail images\n\n"
    "usage: thumbnail [options] input.tif output.tif",
    "where options are:",
    " -h #		specify thumbnail image height (default is 274)",
    " -w #		specify thumbnail image width (default is 216)",
    "",
    " -c linear	use linear contrast curve",
    " -c exp50	use 50% exponential contrast curve",
    " -c exp60	use 60% exponential contrast curve",
    " -c exp70	use 70% exponential contrast curve",
    " -c exp80	use 80% exponential contrast curve",
    " -c exp90	use 90% exponential contrast curve",
    " -c exp		use pure exponential contrast curve",
    NULL};

static void usage(int code)
{
    int i;
    FILE *out = (code == EXIT_SUCCESS) ? stdout : stderr;

    fprintf(out, "%s\n\n", TIFFGetVersion());
    for (i = 0; usage_info[i] != NULL; i++)
        fprintf(out, "%s\n", usage_info[i]);
    exit(code);
}