Bug 246761

Summary: convert inverses image
Product: [Fedora] Fedora Reporter: Need Real Name <mal>
Component: ImageMagickAssignee: Norm Murray <nmurray>
Status: CLOSED NOTABUG QA Contact: Fedora Extras Quality Assurance <extras-qa>
Severity: low Docs Contact:
Priority: low    
Version: 6CC: nmurray
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Hardware: All   
OS: Linux   
Whiteboard:
Fixed In Version: Doc Type: Bug Fix
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Clone Of: Environment:
Last Closed: 2007-07-05 03:38:33 UTC Type: ---
Regression: --- Mount Type: ---
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Description Flags
original image
none
convert x.gif -resize 300x y.jpeg
none
convert x.gif z.jpeg none

Description Need Real Name 2007-07-04 17:16:38 UTC
On rpm -q ImageMagick
ImageMagick-6.3.2.9-3
 and other versions convert gif->jpeg
inverts image if resolution changes
 convert x.gif -resize 300x  y.jpeg
In the same time if resolution is the same - everything is OK

Comment 1 Need Real Name 2007-07-04 17:17:39 UTC
Created attachment 158526 [details]
original image

Comment 2 Need Real Name 2007-07-04 17:18:31 UTC
Created attachment 158527 [details]
convert x.gif -resize 300x  y.jpeg

convert x.gif -resize 300x  y.jpeg

Comment 3 Need Real Name 2007-07-04 17:18:56 UTC
Created attachment 158528 [details]
convert x.gif   z.jpeg

convert x.gif	z.jpeg

Comment 4 Norm Murray 2007-07-05 03:38:33 UTC
Original gif image has transparency which the jpeg format doesn't support at all. 

Relying on particular behavior in an undefined conversion is not recommended. If
you look closely at the converted image the difference is not an inversion, but
a value for the transparent region - without resize it is white, with resize it
is black. If you want certainty in what you're doing I suggest making sure you
don't have transparency in your image, or you expand your command line to create
a base layer image of the color you'd like the background to be, then overlay
the gif you are trying to convert and then run the resize and type conversion.