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Making images highlight darker or lighter areas

Posted: 2016-12-08T04:24:13-07:00
by mrburnzie
Hi!

I'm having trouble figuring out how to highlight darker and lighter areas of the image.
I was trying using

Code: Select all

convert in.jpg +contrast out.jpg
and

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convert in.jpg -contrast out.jpg
, but that's not it.

I would like to apply effects like "shadow" and "highlight" to my images. (darker and lighter)

Any suggestions? Thx!

Re: Making images highlight darker or lighter areas

Posted: 2016-12-08T05:21:57-07:00
by snibgo
I don't understand what you want. Perhaps you can link to "before" and "after" examples.

Re: Making images highlight darker or lighter areas

Posted: 2016-12-08T05:40:04-07:00
by Bonzo
I assume the OP wants to lighten shadow areas in a photo to show more detail and to darken lighter areas again to show more detail.

Re: Making images highlight darker or lighter areas

Posted: 2016-12-08T05:41:15-07:00
by mrburnzie
Yes, Bonzo is right. :)

Re: Making images highlight darker or lighter areas

Posted: 2016-12-08T06:16:05-07:00
by mrburnzie
Any suggestions?

Re: Making images highlight darker or lighter areas

Posted: 2016-12-08T06:22:30-07:00
by snibgo
A simple way is:

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convert in.png ( +clone -blur 0x5 +level 55,45%% ) -compose HardLight -composite out.png
Adjust the blur and level as required. You might prefer to adjust only the lightness of the image.

I show some other methods on my pages "Adaptive auto level and gamma" and "[Adaptive] Contrast-limited equalisation".

Re: Making images highlight darker or lighter areas

Posted: 2016-12-08T06:23:42-07:00
by mrburnzie
Thanks, will try it out! :)

Re: Making images highlight darker or lighter areas

Posted: 2016-12-08T06:27:22-07:00
by mrburnzie
I'm getting +clone: command not found :(

To be specific:

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+clone: command not found
fish:  +clone -blur 0x5 +level 55,45%% 
       ^
in command substitution
        called on standard input

convert: no images defined `out.jpg' @ error/convert.c/ConvertImageCommand/3210.

Re: Making images highlight darker or lighter areas

Posted: 2016-12-08T06:41:43-07:00
by snibgo
I should have said: my command is Windows BAT syntax. For bash or other shells, you may need to adjust it, eg escape the parentheses: \( and \).

Re: Making images highlight darker or lighter areas

Posted: 2016-12-08T06:46:22-07:00
by mrburnzie
Okay, thx!

Re: Making images highlight darker or lighter areas

Posted: 2016-12-08T10:16:09-07:00
by fmw42
You can try -brightness-contrast. It has better control than -contrast.