[feat] edit palette - cannot set transparency to multiple indexes

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user0
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[feat] edit palette - cannot set transparency to multiple indexes

Post by user0 »

XnViewMP 1.4.2
Windows11 (22H2), display resolution 3840x2160, dpi scale 150%


Viewer - Edit palette dialog

Issue
It is not possible to set transparency to multiple indexes at once.
No matter how many indexes you go through with ticking checkbox, transparency will be applied only to the last one.
It shall be possible to set transparency to as many indexes as required, and they applied all to image when OK button is pressed.
Last edited by user0 on Sun Sep 14, 2025 1:23 pm, edited 2 times in total.
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xnview
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Re: 1.4.2 - edit pallete - cannot set transparency to multiple indexes

Post by xnview »

8bits palette support only 1 index
Pierre.
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user0
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Re: 1.4.2 - edit pallete - cannot set transparency to multiple indexes

Post by user0 »

xnview wrote: Fri Feb 03, 2023 1:45 pm 8bits palette support only 1 index
What about test_png_B.png, is it still valid 8bit png?
TweakPNG allows to edit alpha channel of individual color.
test_png_A.png
test_png_B.png
TweakPNG_vs_xnview.png

Also note the handy indicator of transparency in TweakPNG (red oval on x scale under each color)

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Last edited by user0 on Thu Mar 09, 2023 10:37 am, edited 4 times in total.
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Re: 1.4.2 - edit pallete - cannot set transparency to multiple indexes

Post by user0 »

updated previous post with example
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Re: 1.4.2 - edit pallete - cannot set transparency to multiple indexes

Post by xnview »

user0 wrote: Fri Feb 03, 2023 2:08 pm TweakPNG allows to edit alpha channel of individual color.
yes but not supported by XnView
Pierre.
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Re: 1.4.2 - edit pallete - cannot set transparency to multiple indexes

Post by user0 »

it would be handy to have such support one day :D