Hi,
question
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I have a question about JPEG compression using the convert command-line utility. I do not know if the images I use will be JPEG2000, JPEG or a mixture (I suspect this is so).
For each of these images, I wish to take a given JPEG file, infile.jpg, and produce a set of output JPEG files having the following compression percentages:
10,20,30,40,50,60,70,80,85,90,92,95,98. They would have names like outfile10.jpg, outfile20.jpg, etc
I see I have to use the -quality option. However, I do not understand how to map to these percentage values. i have looked at the documentation (http://www.imagemagick.org/script/comma ... hp#quality) but it does not say.
Any help would be greatly appreciated
Thanks
Matthew
platform
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I am using convert at the command-line on a 32-bit Ubuntu Linux system (uname -a ->Linux cseepg12y 3.13.0-53-generic #89-Ubuntu SMP Wed May 20 10:34:28 UTC 2015 i686 i686 i686 GNU/Linux)
$ convert -version
Version: ImageMagick 6.7.7-10 2014-03-06 Q16 http://www.imagemagick.org
Copyright: Copyright (C) 1999-2012 ImageMagick Studio LLC
Features: OpenMP
JPEG compression
- fmw42
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Re: JPEG compression
see -define jpeg:extent={size} at http://www.imagemagick.org/Usage/formats/#jpg_write
alternately use my script downsize, at the link below, which iterates to find the given file size
alternately use my script downsize, at the link below, which iterates to find the given file size