NConvert : How to keep PNG tranparency after PNG Compression and Converting in Indexed Colors

Discussions on NConvert - the command line tool for image conversion and manipulation

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PREUX
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Joined: Mon Feb 18, 2019 7:53 pm

NConvert : How to keep PNG tranparency after PNG Compression and Converting in Indexed Colors

Post by PREUX » Mon Feb 18, 2019 8:09 pm

Hello

My purpose is to decrease the file size of several png files.
I wish to make this correction with a command line such as :

"nconvert.exe" -o "Output.png" -clevel 9 -colors 8 "Input.png"

The conversion is made but I loose initial image tranparency.
How to find the PNG transparency.

Thanks

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xnview
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Re: NConvert : How to keep PNG tranparency after PNG Compression and Converting in Indexed Colors

Post by xnview » Tue Feb 19, 2019 7:41 am

if you decrease colors you can't keep transparency
Pierre.

PREUX
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Joined: Mon Feb 18, 2019 7:53 pm

Re: NConvert : How to keep PNG tranparency after PNG Compression and Converting in Indexed Colors

Post by PREUX » Tue Feb 19, 2019 2:32 pm

With the option : -colors 8 then the number of colors is reduced to 8 but it's not sufficient.

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