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June 2006
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2006.06.07 08:50 "Re: TIFFWriteRawStrip with multi-strip?", by Gerben Vos
Pallek, Bernie: #CIPO - OPIC wrote: > > 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. Joris replied: > 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. ...not to mention that G4 produces a stream of bits, not bytes, so the boundary between two strips will not fall on a byte boundary in most cases, and it is even less likely that it will be regular enough to determine a rows-per-strip number. Gerben Vos.