jamesd@robohack.uucp (James P. Duhault) (07/01/90)
I am in need of source code (preferably 'C') for uncompressing
TIFF type 2 compression. The method used is Modified Huffman
encoding so anything relating to this technique may be helpful.
Also, another name for this method is CCITT group 2 compression.
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James Duhaultmarking@drivax.UUCP (M.Marking) (07/03/90)
jamesd@robohack.uucp (James P. Duhault) writes:
) I am in need of source code (preferably 'C') for uncompressing
) TIFF type 2 compression. The method used is Modified Huffman
) encoding so anything relating to this technique may be helpful.
) Also, another name for this method is CCITT group 2 compression.
TIFF type 2 compression is CCITT group 3 1-dimensional encoding (not
group 2). There are several sources for code:
Aldus (the Pagemaker people) offers a TIFF toolkit. I believe
(but am not certain) that it contains source code. 411
First Avenue South, Seattle WA 98104. (206)628-6593. Aldus
also is the source for the TIFF specification.
DEST (the scanner people) once had a TIFF toolkit that
included source. Now the kit is sold by Image Software
Associates. $25 (?). ISA, R&D, Box 1634, Danville CA 94526.
(Specify PC or Macintosh.) There was an article in Dr. Dobbs
a couple of years ago about this, but I don't know the date.
The C Users Group has group 3 and 4 encoding and decoding
routines on volume 317. $8 + shipping. 2601 Iowa Street,
Lawrence KS 66046. (913)841-1631. There are two algorithms
for decoding each format; one of the Group 3 algorithms
is described in the June issue of the C Users Journal.
TIFF Type 2 is very similar to facsimile group 3, except that TIFF
dispenses with EOL codes and pads every scan line to the next byte
boundary.