Legacy ImageMagick Discussions Archive

I am trying to take an image, make ALL of it black, except for a specific color range (of DarkOliveGreen) but not having luck

The image has alpha (PNG alpha, not an actual Alpha channel), which I want to also make go away.

convert imageIn.png -fuzz 7.5% -fill white -opaque DarkOliveGreen PNG24:imageOut.png

How do I select everything EXCEPT the above color range and make it black?

see
http://www.imagemagick.org/script/comma ... php#opaque

"Use +opaque to paint any pixel that does not match the target color."

P.S. Please always provide your IM version and platform when asking questions. See viewtopic.php?f=1&t=9620

Thank you very much!

fmw42 wrote:P.S. Please always provide your IM version and platform when asking questions. See viewtopic.php?f=1&t=9620

Absolutely...sorry about that.... 6.9.2-4 Q8 x64 windows 7 Pro

You do not say what your platform is. IM syntax differs on Windows and Unix

fmw42 wrote:

Code: Select all

convert imageIn.png -alpha off -fuzz 7.5% -fill white -opaque DarkOliveGreen \
-fuzz 0 -fill black +opaque white PNG24:imageOut.png

That yields an entirely black image.

Are you on Windows or Unix? If Windows, then try
Otherwise, please post your image to some place such as dropbox.com and put the URL here, so we can test with it.

It is Windows...(I had previously edited my post to include that) and I am using command line batch (cmd) files...(yes I remembered to use %% this time )

Thanks! I am still getting the hang of all that this amazing program can do, but more importantly, HOW to get there...

fmw42 wrote:Are you on Windows or Unix? If Windows, then try

Code: Select all

convert imageIn.png -alpha off -fuzz 7.5% -fill white -opaque DarkOliveGreen ^
-fuzz 0 -fill black +opaque white PNG24:imageOut.png

Otherwise, please post your image to some place such as dropbox.com and put the URL here, so we can test with it.

For new users, see
http://www.imagemagick.org/script/comma ... essing.php
http://www.imagemagick.org/script/comma ... ptions.php
http://www.imagemagick.org/Usage/reference.html
http://www.imagemagick.org/Usage/

And don't be shy about asking questions on the forum.

see also
http://www.imagemagick.org/Usage/windows/

In the end, this worked:

convert ImageIn.png -alpha remove -fuzz 7.5%% -fill black +opaque DarkOliveGreen -fill white -opaque DarkOliveGreen PNG24:ImageOut.png

So that very much helped me figure it out...thanks!

This gives me an entirely black image except where I had green, and then turns that to white....perfect!

That is why one needs to provide the platform you use each time, so that we can provide the correct syntax. Also in bat files you do need to double the % to %%. For normal terminal commands and bat files, you need to use ^ for new line markers and and when using percents do not escape with \. See http://www.imagemagick.org/Usage/windows/