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How do I convert a JPG into a 50% transparent PNG?
Posted: 2017-12-22T01:23:59-07:00
by xberg
Hi,
I want to transform any JPG into a 50% transparent PNG.
I found how to make a specific color fully transparent with:
Code: Select all
magick convert 1.jpg -fuzz 8%% -transparent white 1.png
But I don't want this: I want all the JPG to be a 50% opaque PNG.
Thanks
Re: How do I convert a JPG into a 50% transparent PNG?
Posted: 2017-12-22T01:44:11-07:00
by snibgo
Code: Select all
magick in.jpg -alpha set -channel A -evaluate set 50% +channel out.png
Re: How do I convert a JPG into a 50% transparent PNG?
Posted: 2017-12-22T01:47:17-07:00
by xberg
Thank you!
Great!! What's the +channel at the end for?
Re: How do I convert a JPG into a 50% transparent PNG?
Posted: 2017-12-22T02:05:53-07:00
by snibgo
"-channel A" means "apply all following operations to just the Alpha channel". "+channel" means "set the default, which is that all following operations apply to all channels".
In this case it is superfluous, but good practice is: whenever you have a "-channel", you should always have a "+channel" somewhere.
Re: How do I convert a JPG into a 50% transparent PNG?
Posted: 2017-12-22T02:18:17-07:00
by xberg
Thanks! Great explanations
