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January 2019
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2019.01.13 19:17 "Re: tiffcp altering image contents (in contrast to what the manual says)?", by Bob Friesenhahn
On Sun, 13 Jan 2019, Binarus wrote: > > "C:\Program Files\GraphicsMagick-1.3.25-Q16\gm.exe" convert a.tif b.tif > -compress jpeg -quality 90 1.tif > > If I got you right, GraphicsMagick probably applies the problematic > OJPEG compression when executing the command above. We will > investigate if we can change that. In the meantime, if our > investigations don't lead to anything, could you eventually give a > hint regarding an alternative procedure for that first step? GraphicsMagick uses libtiff to write TIFF so it will never output OJPEG compression. However, since February 7, 2015, GraphicsMagick uses YCbCr encoding when JPEG compression is requested for an RGB image because the resulting file is much smaller. This might be a factor. By the way, my own email to you was also bounced due a complaint about SPF records but my mail server offers one (unlike the one that Richard unfortunately uses) and so your bounce is the first one I have ever seen complaining about SFP records. Bob -- Bob Friesenhahn bfriesen@simple.dallas.tx.us, http://www.simplesystems.org/users/bfriesen/ GraphicsMagick Maintainer, http://www.GraphicsMagick.org/ Public Key, http://www.simplesystems.org/users/bfriesen/public-key.txt _______________________________________________ Tiff mailing list Tiff@lists.osgeo.org https://lists.osgeo.org/mailman/listinfo/tiff