2005.09.23 21:11 "[Tiff] Additional Lossless Compression Schemes", by Frank
Warmerdam
Thread
2005.09.27 02:20 "Re: [Tiff] Additional Lossless Compression Schemes", by Joris Van Damme
I recommend aiming for 2 megabyte instead. That'll give ZLib data with lots of redundancy to eliminate, instead of limiting its view to a single scanline or just a couple of them, and will contribute quite a bit to a good compression ratio.
I think that 2 megabyte is wasteful. Also, while 2 megabyte may seem like just a little bit of memory in a modern computer, it may be a lot of memory for a device like a photo printer.
You are confusing the need of LibTiff (allocate, store and decompress complete strip into an allocated and stored decompressed... euh, complete strip, in a single go) with the need of the format (seperate tiles/strips are perfectly streamable if their compression scheme is, and all compression schemes are, sofar).
But there is of course at least one good reason to confuse these, LibTiff being the single very widely used library, so I can partly agree. On the other hand, LibTiff is not likely a good choice for the software inside a low memory device, anyway, for this very reason, since 2 megabyte strips/tiles do exist, and in fact with G3 or G4 compression it is rather common to encode as a single-strip image whatever its size.
Joris Van Damme
info@awaresystems.be
http://www.awaresystems.be/
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