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August 2006
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2006.08.04 15:00 "Re: libTiff and MSVC 6.0", by Bernie Pallek
Sean wrote:
> __declspec(dllexport) write2DTIFF(char *fname,
> unsigned long *buf,
[...]
> tif = TIFFOpen(fname, "w");
> TIFFSetField(tif, TIFFTAG_IMAGEWIDTH, width);
> TIFFSetField(tif, TIFFTAG_IMAGELENGTH, height);
> TIFFSetField(tif, TIFFTAG_COMPRESSION, COMPRESSION_LZW);
> TIFFSetField(tif, TIFFTAG_BITSPERSAMPLE, 16);
Okay, some more things have occurred to me. Two potential problems:
1) BitsPerSample is set to 16, while the allowed values (for greyscale) are
4 and 8.
2) "unsigned long *buf" points to 32-bit values, which differ from the
BitsPerSample size (16-bit samples).
Try using a value of 8 for BitsPerSample, change "unsigned long *buf" to
"unsigned char * buf", copy your original data into a temporary buffer,
which contains the original samples each divided by 256 (or bit-shifted
right by 8), and pass that temporary buffer.
> TIFFSetField(tif, TIFFTAG_SAMPLESPERPIXEL, 1);
> TIFFSetField(tif, TIFFTAG_PLANARCONFIG, PLANARCONFIG_CONTIG);
> if((TIFFWriteEncodedStrip(tif, 0, buf, width*height)) == -1){
> fprintf(stderr, "TIFFWriteEncodedStrip failed.\n");
> }
> TIFFClose(tif);