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Bug 246761 - convert inverses image
convert inverses image
Product: Fedora
Classification: Fedora
Component: ImageMagick (Show other bugs)
All Linux
low Severity low
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Assigned To: Norm Murray
Fedora Extras Quality Assurance
Depends On:
  Show dependency treegraph
Reported: 2007-07-04 13:16 EDT by Need Real Name
Modified: 2007-11-30 17:12 EST (History)
1 user (show)

See Also:
Fixed In Version:
Doc Type: Bug Fix
Doc Text:
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Clone Of:
Last Closed: 2007-07-04 23:38:33 EDT
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oVirt Team: ---
RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: ---

Attachments (Terms of Use)
original image (18.87 KB, image/gif)
2007-07-04 13:17 EDT, Need Real Name
no flags Details
convert x.gif -resize 300x y.jpeg (37.81 KB, image/jpeg)
2007-07-04 13:18 EDT, Need Real Name
no flags Details
convert x.gif z.jpeg (102.99 KB, image/jpeg)
2007-07-04 13:18 EDT, Need Real Name
no flags Details

  None (edit)
Description Need Real Name 2007-07-04 13:16:38 EDT
On rpm -q ImageMagick
 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 13:17:39 EDT
Created attachment 158526 [details]
original image
Comment 2 Need Real Name 2007-07-04 13:18:31 EDT
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 13:18:56 EDT
Created attachment 158528 [details]
convert x.gif   z.jpeg

convert x.gif	z.jpeg
Comment 4 Norm Murray 2007-07-04 23:38:33 EDT
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. 

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