AWARE SYSTEMS
TIFF and LibTiff Mail List Archive

Thread

2007.09.23 16:42 "[Tiff] G3 fax: EOL needed at the beginning of each strip?", by ComSquare Martin Osieka
2007.09.24 01:27 "Re: [Tiff] G3 fax: EOL needed at the beginning of each strip?", by Bob Friesenhahn
2007.09.24 05:56 "Re: [Tiff] G3 fax: EOL needed at the beginning of each strip?", by Joris
2007.09.24 07:24 "Re: [Tiff] G3 fax: EOL needed at the beginning of each strip?", by ComSquare Martin Osieka
2007.09.24 07:51 "Re: [Tiff] G3 fax: EOL needed at the beginning of each strip?", by Joris
2007.09.24 08:01 "Re: [Tiff] G3 fax: EOL needed at the beginning of each strip?", by Andy Cave
2007.09.24 08:32 "Re: [Tiff] G3 fax: EOL needed at the beginning of each strip?", by Joris
2007.09.24 08:45 "Re: [Tiff] G3 fax: EOL needed at the beginning of each strip?", by Andy Cave
2007.09.24 09:03 "Re: [Tiff] G3 fax: EOL needed at the beginning of each strip?", by Joris
2007.09.24 08:52 "Re: [Tiff] G3 fax: EOL needed at the beginning of each strip?", by ComSquare Martin Osieka
2007.09.24 08:58 "Re: [Tiff] G3 fax: EOL needed at the beginning of each strip?", by Andy Cave

2007.09.24 09:03 "Re: [Tiff] G3 fax: EOL needed at the beginning of each strip?", by Joris

Andy,

Who says that a strip is equiavlent to a page? The TIFF spec doesn't.

I don't completely agree. Every strip/tile is a completely separate, individual entity when it comes to compression. Note how the opposite is part of what got us into the OJPEG trouble. Also note that in the TIFF decoding pipeline, the decompression step comes before the strip/tile/plane re-assembling step(s) (or in the encoding pipeline, the compression step comes after the strip/tile/plane disassembling step(s)), and therefore it just makes sense to view each strip/tile as a separate and whole unit when it comes to compression. Therefore, the notion of 'strip/tile' translates to the notion of 'complete image' or 'page' in the G3/G4 specs. Therefore, I too lean towards your view quoted below:

I personally lean towards the view that you should treat each strip/tile as a separate (part of the) image and therefore each strip should being with an EOL (that's what our Lightning TIFF plugin for

> the Hqn RIP does)

Martin seems to have located a paragraph in the TIFF 6.0 spec that backs up our view, but I think it applies even without this particular paragraph as it is a general rule that makes TIFF work, independent even of this particular compression mode.

Best regards,

Joris Van Damme
info@awaresystems.be
http://www.awaresystems.be/
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