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Marvin wrote:
> Is it possible to split a G4 image into several G4
> subimages without decompressing?

Probably not.  The vertical (2D) compression scheme relies on a previous
line (an imaginary white line in the case of the first), so even if you
could break the compressed data block into sub-blocks at line boundaries
(already difficult/impossible), only the first sub-block would be able to
use the imaginary white line above the image; the rest of the sub-blocks
would be depending on the last line of the previous sub-block, which
wouldn't be handled well by the standard decompression algorithm.


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	LibTiff Mailing List TIFF and LibTiff Mailing List Archive November 2006 Previous Thread Next Thread Previous by Thread Next by Thread Previous by Date Next by Date Contact The TIFF Mailing List Homepage This list is run by Frank Warmerdam Archive maintained by AWare Systems	Thread 2006.11.01 15:47 "splitting G4 image without decompression", by Marvin Fresno 2006.11.01 16:02 "Re: splitting G4 image without decompression", by Bernie Pallek 2006.11.01 16:02 "Re: splitting G4 image without decompression", by Bernie Pallek Marvin wrote: > Is it possible to split a G4 image into several G4 > subimages without decompressing? Probably not. The vertical (2D) compression scheme relies on a previous line (an imaginary white line in the case of the first), so even if you could break the compressed data block into sub-blocks at line boundaries (already difficult/impossible), only the first sub-block would be able to use the imaginary white line above the image; the rest of the sub-blocks would be depending on the last line of the previous sub-block, which wouldn't be handled well by the standard decompression algorithm.

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2006.11.01 16:02 "Re: splitting G4 image without decompression", by Bernie Pallek