|TIFF and LibTiff Mailing List Archive|
LibTiff Mailing List
2007.05.13 22:49 "Re: JBIG2 compressed TIF question about bpp", by T T
Toby, I guess you're right about needing to binarize the image first. For some reason I thought it had to do with the TIF specification, but I guess it's immaterial. When the software saves TIFF G4 compressed I guess it's getting binarized internally first before the compression is applied and for some reason with JBIG2 compressed TIF and Huffman RLE compressed TIF they're not getting binarized first and you need to explicitly do it. Thanks, Toby Thain <firstname.lastname@example.org> wrote: On 13-May-07, at 2:48 PM, t t wrote: > Toby, > > The software I'm using has a compression format just called RLE, I > looked at the resulting image in another viewer and it say it was > Huffman RLE (Huffman coding). Here's the exact thread I was > referencing: http://www.asmail.be/msg0054717898.html > > I can also save with PackBits compression and maintain 24-bit (TIF) > without a problem. I see PackBits is also mentioned in the reply > to the thread I mentioned above. > > So I'm facing a similar situation with the JBIG2 as I am with > Huffman RLE. Hi, So the issue seems to be that the software doesn't downsample to 1 bit when saving TIFF but you want to use JBIG2 or "Huffman RLE"? Does this matter? It presumably doesn't use libtiff either, so I'm not sure how this list can help? --Toby > > Thanks. > > Toby Thain wrote: > On 13-May-07, at 1:47 PM, t t wrote: > > > ... > > I found a very similar question in the archives here where somebody > > wanted to save a non 1-bit TIF with RLE encoding but the TIF > > specification doesn't support that and he would have to take it > > down to 1-bit first to do it. > > Which RLE do you mean? This isn't the case with PackBits. > > --Toby > > > > > So is this a problem with the software I'm using or does the TIF > > specification not support it? > > > > Thanks, > > > > Be a better Globetrotter. Get better travel answers from someone > > who knows. > > Yahoo! Answers - Check it out. > > _______________________________________________ > > Tiff mailing list: Tiff@lists.maptools.org > > http://lists.maptools.org/mailman/listinfo/tiff > > http://www.remotesensing.org/libtiff/ > > > > Don't pick lemons. > See all the new 2007 cars at Yahoo! Autos. > > Be a PS3 game guru. > Get your game face on with the latest PS3 news and previews at > Yahoo! Games. --------------------------------- Be a better Globetrotter. Get better travel answers from someone who knows. Yahoo! Answers - Check it out. --------------------------------- Be a better Globetrotter. Get better travel answers from someone who knows. Yahoo! Answers - Check it out.