Bug 305636 - crop uses 0.75 jpeg quality factor instead of file quality factor
Summary: crop uses 0.75 jpeg quality factor instead of file quality factor
Status: RESOLVED DUPLICATE of bug 294594
Alias: None
Product: gwenview
Classification: Applications
Component: general (show other bugs)
Version: 2.9.0
Platform: Mandriva RPMs Linux
: NOR normal
Target Milestone: ---
Assignee: Gwenview Bugs
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2012-08-22 22:39 UTC by emmanuel.manchester314
Modified: 2012-12-08 20:56 UTC (History)
3 users (show)

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Description emmanuel.manchester314 2012-08-22 22:39:35 UTC
When cropping, file is saved at the 0.75 jpeg quality factor, irrespective of the orginal file quality

You can check with imagmaick command :
identify -verbose *.jpg *.jpeg | grep -i quality

gwenview should 
1) save with the same quality factor
2) offer an option in the general settings to offer a fixed factor different of that of the read file

Thanks

On mandriva cooker and and 2011
Comment 1 Christoph Feck 2012-08-23 00:28:08 UTC
> save with the same quality factor

If you want to retain quality, you have to save to a lossless format, or with q=1.00 if you need JPEG. What imagemagik tells you is information, it doesn't mean that it's best to save again at this setting.
Comment 2 emmanuel.manchester314 2012-08-23 02:38:57 UTC
it is the same problem with red eye reduction

by the way this is faster : identify -format "%Q" *.jpeg
than identify -verbose *.jpg *.jpeg | grep -i quality

>>If you want to retain quality, you have to save to a lossless format
Indeed, and I am using raw format as well.
plus I can use jpegtran  -crop WxH+X+Y
<<Crop the image to a rectangular region of width W and height H, starting at point X,Y.  The 
**lossless** crop feature>>

I suppose gwenview uses the crop feature (or libraries) of convert / imagemagick
This may not be lossless, I do not know

Nevertheless, I do not want gwenview to choose the quality factor for me.
Especially to go from 0.94 to 0.75

>>it doesn't mean that it's best to save again at this setting.
This wahy I am asking it saves with the same quality factor as the original file
Comment 3 Benni Hill 2012-12-08 20:56:40 UTC

*** This bug has been marked as a duplicate of bug 294594 ***