libtiff: TIFFWriteRGBAImage()?

i was wondering if you might be able to help me with a problem i have with libtiff....

i am having problems writing RGBA information into tiff files, i am using the convenient:

TIFFReadRGBAImage(tif, width, height, pixels, 0);

to read in, display and edit the data contained in 'pixels' [a uint32*].... but when i want to write out the altered 'pixels' into a tiff file.... there is no corresponding 'TIFFWriteRGBAImage()'.... and i can't find any documentation or examples to help me...

anyone use libtiff?

nevermind, found this wee beauty in the 'tools' section... tiff2rgba.c... thanks frank... you the man!

Code:

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

#include "tiffio.h"

#define        streq(a,b)        (strcmp(a,b) == 0)
#define        CopyField(tag, v) \
    if (TIFFGetField(in, tag, &v)) TIFFSetField(out, tag, v)

#ifndef howmany
#define        howmany(x, y)        (((x)+((y)-1))/(y))
#endif
#define        roundup(x, y)        (howmany(x,y)*((uint32)(y)))

uint16        compression = COMPRESSION_PACKBITS;
uint32        rowsperstrip = (uint32) -1;
int        process_by_block = 0; /* default is whole image at once */
int    no_alpha = 0;


static        int tiffcvt(TIFF* in, TIFF* out);
static        void usage(void);

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

    while ((c = getopt(argc, argv, "c:r:t:bn")) != -1)
        switch (c) {
          case 'b':
            process_by_block = 1;
            break;
           
          case 'c':
            if (streq(optarg, "none"))
                compression = COMPRESSION_NONE;
            else if (streq(optarg, "packbits"))
                compression = COMPRESSION_PACKBITS;
            else if (streq(optarg, "lzw"))
                compression = COMPRESSION_LZW;
            else if (streq(optarg, "jpeg"))
                compression = COMPRESSION_JPEG;
            else if (streq(optarg, "zip"))
                compression = COMPRESSION_DEFLATE;
            else
                usage();
            break;

          case 'r':
            rowsperstrip = atoi(optarg);
            break;

          case 't':
            rowsperstrip = atoi(optarg);
            break;
           
          case 'n':
            no_alpha = 1;
            break;
           
          case '?':
            usage();
            /*NOTREACHED*/
        }

    if (argc - optind < 2)
        usage();

    out = TIFFOpen(argv[argc-1], "w");
    if (out == NULL)
        return (-2);

    for (; optind < argc-1; optind++) {
        in = TIFFOpen(argv[optind], "r");
        if (in != NULL) {
            do {
                if (!tiffcvt(in, out) ||
                    !TIFFWriteDirectory(out)) {
                    (void) TIFFClose(out);
                    return (1);
                }
            } while (TIFFReadDirectory(in));
            (void) TIFFClose(in);
        }
    }
    (void) TIFFClose(out);
    return (0);
}

static int
cvt_by_tile( TIFF *in, TIFF *out )

{
    uint32* raster;                        /* retrieve RGBA image */
    uint32  width, height;                /* image width & height */
    uint32  tile_width, tile_height;
    uint32  row, col;
    uint32  *wrk_line;
    int            ok = 1;

    TIFFGetField(in, TIFFTAG_IMAGEWIDTH, &width);
    TIFFGetField(in, TIFFTAG_IMAGELENGTH, &height);

    if( !TIFFGetField(in, TIFFTAG_TILEWIDTH, &tile_width)
        || !TIFFGetField(in, TIFFTAG_TILELENGTH, &tile_height) ) {
        TIFFError(TIFFFileName(in), "Source image not tiled");
        return (0);
    }
   
    TIFFSetField(out, TIFFTAG_TILEWIDTH, tile_width );
    TIFFSetField(out, TIFFTAG_TILELENGTH, tile_height );

    /*
    * Allocate tile buffer
    */
    raster = (uint32*)_TIFFmalloc(tile_width * tile_height * sizeof (uint32));
    if (raster == 0) {
        TIFFError(TIFFFileName(in), "No space for raster buffer");
        return (0);
    }

    /*
    * Allocate a scanline buffer for swapping during the vertical
    * mirroring pass.
    */
    wrk_line = (uint32*)_TIFFmalloc(tile_width * sizeof (uint32));
    if (wrk_line == 0) {
        TIFFError(TIFFFileName(in), "No space for raster scanline buffer");
        ok = 0;
    }
   
    /*
    * Loop over the tiles.
    */
    for( row = 0; ok && row < height; row += tile_height )
    {
        for( col = 0; ok && col < width; col += tile_width )
        {
            int                i_row;

            /* Read the tile into an RGBA array */
            if (!TIFFReadRGBATile(in, col, row, raster)) {
                ok = 0;
                break;
            }

            /*
            * For some reason the TIFFReadRGBATile() function chooses the
            * lower left corner as the origin.  Vertically mirror scanlines.
            */
            for( i_row = 0; i_row < tile_height / 2; i_row++ )
            {
                uint32        *top_line, *bottom_line;

                top_line = raster + tile_width * i_row;
                bottom_line = raster + tile_width * (tile_height-i_row-1);

                _TIFFmemcpy(wrk_line, top_line, 4*tile_width);
                _TIFFmemcpy(top_line, bottom_line, 4*tile_width);
                _TIFFmemcpy(bottom_line, wrk_line, 4*tile_width);
            }

            /*
            * Write out the result in a tile.
            */

            if( TIFFWriteEncodedTile( out,
                                      TIFFComputeTile( out, col, row, 0, 0),
                                      raster,
                                      4 * tile_width * tile_height ) == -1 )
            {
                ok = 0;
                break;
            }
        }
    }

    _TIFFfree( raster );
    _TIFFfree( wrk_line );

    return ok;
}

static int
cvt_by_strip( TIFF *in, TIFF *out )

{
    uint32* raster;                        /* retrieve RGBA image */
    uint32  width, height;                /* image width & height */
    uint32  row;
    uint32  *wrk_line;
    int            ok = 1;

    TIFFGetField(in, TIFFTAG_IMAGEWIDTH, &width);
    TIFFGetField(in, TIFFTAG_IMAGELENGTH, &height);

    if( !TIFFGetField(in, TIFFTAG_ROWSPERSTRIP, &rowsperstrip) ) {
        TIFFError(TIFFFileName(in), "Source image not in strips");
        return (0);
    }
   
    TIFFSetField(out, TIFFTAG_ROWSPERSTRIP, rowsperstrip);

    /*
    * Allocate strip buffer
    */
    raster = (uint32*)_TIFFmalloc(width * rowsperstrip * sizeof (uint32));
    if (raster == 0) {
        TIFFError(TIFFFileName(in), "No space for raster buffer");
        return (0);
    }

    /*
    * Allocate a scanline buffer for swapping during the vertical
    * mirroring pass.
    */
    wrk_line = (uint32*)_TIFFmalloc(width * sizeof (uint32));
    if (wrk_line == 0) {
        TIFFError(TIFFFileName(in), "No space for raster scanline buffer");
        ok = 0;
    }
   
    /*
    * Loop over the strips.
    */
    for( row = 0; ok && row < height; row += rowsperstrip )
    {
        int        rows_to_write, i_row;

        /* Read the strip into an RGBA array */
        if (!TIFFReadRGBAStrip(in, row, raster)) {
            ok = 0;
            break;
        }

        /*
        * Figure out the number of scanlines actually in this strip.
        */
        if( row + rowsperstrip > height )
            rows_to_write = height - row;
        else
            rows_to_write = rowsperstrip;

        /*
        * For some reason the TIFFReadRGBAStrip() function chooses the
        * lower left corner as the origin.  Vertically mirror scanlines.
        */

        for( i_row = 0; i_row < rows_to_write / 2; i_row++ )
        {
            uint32        *top_line, *bottom_line;

            top_line = raster + width * i_row;
            bottom_line = raster + width * (rows_to_write-i_row-1);

            _TIFFmemcpy(wrk_line, top_line, 4*width);
            _TIFFmemcpy(top_line, bottom_line, 4*width);
            _TIFFmemcpy(bottom_line, wrk_line, 4*width);
        }

        /*
        * Write out the result in a strip
        */

        if( TIFFWriteEncodedStrip( out, row / rowsperstrip, raster,
                                  4 * rows_to_write * width ) == -1 )
        {
            ok = 0;
            break;
        }
    }

    _TIFFfree( raster );
    _TIFFfree( wrk_line );

    return ok;
}

/*
 * cvt_whole_image()
 *
 * read the whole image into one big RGBA buffer and then write out
 * strips from that.  This is using the traditional TIFFReadRGBAImage()
 * API that we trust.
 */

static int
cvt_whole_image( TIFF *in, TIFF *out )

{
    uint32* raster;                        /* retrieve RGBA image */
    uint32  width, height;                /* image width & height */
    uint32        row;
    uint32  *wrk_line;
       
       
    TIFFGetField(in, TIFFTAG_IMAGEWIDTH, &width);
    TIFFGetField(in, TIFFTAG_IMAGELENGTH, &height);

    rowsperstrip = TIFFDefaultStripSize(out, rowsperstrip);
    TIFFSetField(out, TIFFTAG_ROWSPERSTRIP, rowsperstrip);

    raster = (uint32*)_TIFFmalloc(width * height * sizeof (uint32));
    if (raster == 0) {
        TIFFError(TIFFFileName(in), "No space for raster buffer");
        return (0);
    }

    /* Read the image in one chunk into an RGBA array */
    if (!TIFFReadRGBAImage(in, width, height, raster, 0)) {
        _TIFFfree(raster);
        return (0);
    }

    /* For some reason the TIFFReadRGBAImage() function chooses the
      lower left corner as the origin.  Vertically mirror scanlines. */

    wrk_line = (uint32*)_TIFFmalloc(width * sizeof (uint32));
    if (wrk_line == 0) {
        TIFFError(TIFFFileName(in), "No space for raster scanline buffer");
        return (0);
    }
   
    for( row = 0; row < height / 2; row++ )
    {
        uint32        *top_line, *bottom_line;

        top_line = raster + width * row;
        bottom_line = raster + width * (height-row-1);

        _TIFFmemcpy(wrk_line, top_line, 4*width);
        _TIFFmemcpy(top_line, bottom_line, 4*width);
        _TIFFmemcpy(bottom_line, wrk_line, 4*width);
    }

    _TIFFfree( wrk_line );

    /*
    ** Do we want to strip away alpha components?
    */
    if( no_alpha )
    {
        int        pixel_count = width * height;
        unsigned char *src, *dst;

        src = (unsigned char *) raster;
        dst = (unsigned char *) raster;
        while( pixel_count > 0 )
        {
            *(dst++) = *(src++);
            *(dst++) = *(src++);
            *(dst++) = *(src++);
            src++;
            pixel_count--;
        }
    }

    /* Write out the result in strips */

    for( row = 0; row < height; row += rowsperstrip )
    {
        unsigned char * raster_strip;
        int        rows_to_write;
        int        bytes_per_pixel;

        if( no_alpha )
        {
            raster_strip = ((unsigned char *) raster) + 3 * row * width;
            bytes_per_pixel = 3;
        }
        else
        {
            raster_strip = (unsigned char *) (raster + row * width);
            bytes_per_pixel = 4;
        }

        if( row + rowsperstrip > height )
            rows_to_write = height - row;
        else
            rows_to_write = rowsperstrip;

        if( TIFFWriteEncodedStrip( out, row / rowsperstrip, raster_strip,
                            bytes_per_pixel * rows_to_write * width ) == -1 )
        {
            _TIFFfree( raster );
            return 0;
        }
    }

    _TIFFfree( raster );

    return 1;
}


static int
tiffcvt(TIFF* in, TIFF* out)
{
        uint32 width, height;                /* image width & height */
        uint16 shortv;
        float floatv;
        char *stringv;
        uint32 longv;
        uint16 v[1];

        TIFFGetField(in, TIFFTAG_IMAGEWIDTH, &width);
        TIFFGetField(in, TIFFTAG_IMAGELENGTH, &height);

        CopyField(TIFFTAG_SUBFILETYPE, longv);
        TIFFSetField(out, TIFFTAG_IMAGEWIDTH, width);
        TIFFSetField(out, TIFFTAG_IMAGELENGTH, height);
        TIFFSetField(out, TIFFTAG_BITSPERSAMPLE, 8);
        TIFFSetField(out, TIFFTAG_COMPRESSION, compression);
        TIFFSetField(out, TIFFTAG_PHOTOMETRIC, PHOTOMETRIC_RGB);

        CopyField(TIFFTAG_FILLORDER, shortv);
        TIFFSetField(out, TIFFTAG_ORIENTATION, ORIENTATION_TOPLEFT);

        if( no_alpha )
            TIFFSetField(out, TIFFTAG_SAMPLESPERPIXEL, 3);
        else
            TIFFSetField(out, TIFFTAG_SAMPLESPERPIXEL, 4);

        if( !no_alpha )
        {
            v[0] = EXTRASAMPLE_ASSOCALPHA;
            TIFFSetField(out, TIFFTAG_EXTRASAMPLES, 1, v);
        }

        CopyField(TIFFTAG_XRESOLUTION, floatv);
        CopyField(TIFFTAG_YRESOLUTION, floatv);
        CopyField(TIFFTAG_RESOLUTIONUNIT, shortv);
        TIFFSetField(out, TIFFTAG_PLANARCONFIG, PLANARCONFIG_CONTIG);
        TIFFSetField(out, TIFFTAG_SOFTWARE, TIFFGetVersion());
        CopyField(TIFFTAG_DOCUMENTNAME, stringv);

        if( process_by_block && TIFFIsTiled( in ) )
            return( cvt_by_tile( in, out ) );
        else if( process_by_block )
            return( cvt_by_strip( in, out ) );
        else
            return( cvt_whole_image( in, out ) );
}

static char* usageMsg[] = {
    "usage: tiff2rgba [-c comp] [-r rows] [-b] input... output\n",
    "where comp is one of the following compression algorithms:\n",
    " jpeg\t\tJPEG encoding\n",
    " zip\t\tLempel-Ziv & Welch encoding\n",
    " lzw\t\tLempel-Ziv & Welch encoding\n",
    " (lzw compression unsupported by default due to Unisys patent enforcement)\n",
    " packbits\tPackBits encoding\n",
    " none\t\tno compression\n",
    "and the other options are:\n",
    " -r\trows/strip\n",
    " -b (progress by block rather than as a whole image)\n",
    " -n don't emit alpha component.\n",
    NULL
};

static void
usage(void)
{
        int i;
        for (i = 0; usageMsg[i]; i++)
                fprintf(stderr, "%s", usageMsg[i]);
        exit(-1);
}

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