Legacy ImageMagick Discussions Archive

Hi,

I want apply a mask to an image. (image and mask have the same dimensions)

input.png (grayscale)
mask.png

I used the next code:

convert input.png mask.png -alpha off -compare CopyOpacity -composite out.png

The mask was applied correctly, but the out.png lost the grayscale (obviously), i think..

Suggestions for applying the mask and not lose the grayscale ?

thanks

Use "-compose" instead of "-compare": If that doesn't help, upload inputs and output to somewhere like dropbox.com and paste the URLs here.

The same :/

Mask image:


Input image:

This is the result:

It looks fine to me. What result do you get? What is wrong with it?

yes, it looks fine.. Sorry, bad example :/

With the next images, you can see the differences.

input:


mask:


Thanks

Again, the result looks fine to me. What is wrong with it?

My result:



My code: Why is different?

Thanks

What version of IM and platform are you using?

Nothing is wrong with it. Your two examples are on different color backgrounds, which show through in the transparent areas.

Version: ImageMagick 6.7.7-10 2014-03-06

Platform: Linux - Ubuntu

Thanks

Your result is darker than mine, because your old version of ImageMagick 6.7.7-10 was confused between linear and non-linear grayscale. I suggest you upgrade to a recent version.

Yes, I update ImageMagick to a recent version and solved my problem.

Thanks