Transparent PNG modified when 'Change color depth' selected

Reported bugs that have been closed and/or resolved

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cday
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Joined: Sun Apr 29, 2012 9:45 am
Location: Cheltenham, U.K.

Transparent PNG modified when 'Change color depth' selected

Post by cday »

When the attached file elite.png with transparency is opened, and Image > Change color depth.... selected, and when the 32 bit option is selected, part of the transparent area becomes black.

The same file opened in another popular software retains full transparency when the colour depth is reduced and the file saved, file attached.

It does seem unlikely that there could be a bug in such a long standing function, but is there another explanation??

Steps to reproduce:

1. Open the attached file elite.png

2. Select Image > Change color depth...

3. Select 32 bit

Attachments
Elite.png
Elite.png (306.7 KiB) Viewed 163 times
Elite_Program_X_256_Colours_32-Bit.png
Elite_Program_X_256_Colours_32-Bit.png (100.27 KiB) Viewed 163 times
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xnview
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Re: Transparent PNG modified when 'Change color depth' selected

Post by xnview »

:bugconfirmed: Thanks to your detailed description I can reproduce the problem.
it's related to this issue, the alpha is replaced
Pierre.
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xnview
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Re: Transparent PNG modified when 'Change color depth' selected

Post by xnview »

This problem is supposed to be fixed in XnView MP 0.98.2. Please check and confirm the bug fix here.
Pierre.
cday
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Posts: 2736
Joined: Sun Apr 29, 2012 9:45 am
Location: Cheltenham, U.K.

Re: Transparent PNG modified when 'Change color depth' selected

Post by cday »

xnview wrote: Mon Feb 22, 2021 10:54 am This problem is supposed to be fixed in XnView MP 0.98.2. Please check and confirm the bug fix here.
Seems to be fixed... :D
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