2007.05.31 21:02 "[Tiff] question about TIFFWriteScanline", by

I have verified that the format of data in the buffer returned by TIFFReadScanline in contiguous mode follows this format:

image(row, col, chan) = buffer[col*channels + chan];

However, when I use the same format with TIFFWriteScanline to write to a file, it mixes up all the channels and I get garbage:

buffer[col*channels + chan] = image(row, col, chan);

As a simple test I have just read in/write out each scanline. In comes an image, out comes a garbled image. So how do I need to reorganize the buffer for writing?

TIFF *tif = TIFFOpen(fname, opt);
uint32 rows;
TIFFGetField(tif, TIFFTAG_IMAGELENGTH, &rows);

uint32 cols;
TIFFGetField(tif, TIFFTAG_IMAGEWIDTH, &cols);

uint16 _channels;

TIFFGetField(tif, TIFFTAG_SAMPLESPERPIXEL, &channels);

uint16 config;

TIFFGetField(tif, TIFFTAG_PLANARCONFIG, &config);

if (config == PLANARCONFIG_CONTIG)
        //scanline organized as: R G B R G B...
{
        tdata_t buf = _TIFFmalloc(TIFFScanlineSize(tif));
        uint8 *b = (uint8*)buf;

        /*open a file for writing*/
        TIFF *out = TIFFOpen("TEST.tif", "w");
        TIFFSetField(out, TIFFTAG_IMAGEWIDTH, (uint32)cols);
        TIFFSetField(out, TIFFTAG_IMAGELENGTH, (uint32)rows);
        TIFFSetField(out, TIFFTAG_SAMPLESPERPIXEL, (uint16)channels);

TIFFTAG_PLANARCONFIG, PLANARCONFIG_CONTIG); TIFFSetField(out,

        /*read/write scanlines back out to new file*/
        for(unsigned int row = 0; row < rows; row++)
        {
                TIFFReadScanline(tif, buf, row);
                TIFFWriteScanline(out, buf, row);
        }

        _TIFFfree(buf);
        TIFFClose(out);

}

TIFFClose(tif);