2006.06.02 16:35 "Re: [Tiff] TIFFWriteRawStrip with multi-strip?", by Joris Van Damme

Bernie,

Pallek, Bernie: #CIPO - OPIC wrote:

I have already-compressed (COMPRESSION_CCITT_T6-type) data which I'd like to bind to a new TIFF file. So, I'm setting rows-per-strip equal to the image length (height), and I'm using something like:

checkCount = TIFFWriteRawStrip(someTifStructInstance, 0, someBuffer, theSizeOfThatBuffer);

and this works just fine.

However, I'd like to now use an arbitrary value for rows-per-strip. But this means I need to find the byte offsets within 'someBuffer' so I can call TIFFWriteRawStrip repeatedly, incrementing the strip number. The crux? Since the data is compressed, how in the crap will I know where each strip's data begins within 'someBuffer'? Each strip is going to vary in size.

This type of compression, G4, encodes each scanline relative to previous scanline. The first scanline is encoded relative to a 'virtual' all-white line. So if you divide the block, the first part will make sense, the second will be corrupted. There's no way you can work around that.

Joris Van Damme
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