dgpe misses dupes when transparency is involved
Reported by Virgil Dupras | September 28th, 2009 @ 05:23 PM | in se2.8.1 me5.6.5 pe1.7.6 (closed)
After having noticed that some exact duplicates had a less-than-100% match in the Cocoa version, I investigated for a few hours (yeah, it took me quite a while to click on that one) and found that images with transparency were the problem.
After some digging I found out the cause of the problem, which is the malloc() on the BitmapContext creation routine. This pixel buffer initialization doesn't zero out the pixels, and when the image is drawn in the buffer, transparent pixels are not touched, which means that these pixels stay undefined.
It means that two pictures that are exactly the same will most likely have different block when analyzed (which is bad).
Comments and changes to this ticket
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Virgil Dupras September 28th, 2009 @ 05:23 PM
- State changed from “new” to “accepted”
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Virgil Dupras September 28th, 2009 @ 05:24 PM
- Assigned user set to “Virgil Dupras”
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Virgil Dupras September 28th, 2009 @ 05:33 PM
- State changed from “accepted” to “fixed”
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Virgil Dupras
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64
dgpe misses dupes when transparency is involved
(from [150]) [#64 state:fixed] fixed a bug in
PictureBloc...