If this is supposed to be only related to the plugin and not the standalone G'MIC tool, then I'm sorry. Please ignore/delete/lock as appropriate.

But if that's within the scope, what happens is that some images, particularly drawings or uncolored comic pages/strips/pin-ups (bunch of random old downloads from blogs or sites), but also some grayscales, will pretty much have the white background replaced by a full red with this command:

gmic *.jpg -montage A -o montage.jpg

Just as if they had a full-red layer on multiply above them.

I tried also first mogrifying them into RGB, assuming it was something possibly related with a grayscale colorspace, but it makes no difference.

A list of files, for example (everything pretty much safe for work... not that one should be paying attention to this at work, though ):

https://i.pinimg.com/originals/42/29/57 ... 64913d.jpg

http://www.bleedingcool.com/wp-content/ ... jpg?x70969

https://avatars.mds.yandex.net/get-pdb/ ... 83943/orig

https://www.videogamesartwork.com/sites ... ne_art.jpg


The last one (Joker) gets painted/"multiplied" red, whereas the others are not transformed in this way. So it's not truly "random", even if it looks that way on superficial appearance.


It's G'MIC version 2.4.1-3, Debian's. But it did happen also in a previous version, whatever it was.



Does anyone know if it's just a bug or is there some "hidden" obscure file specification and configurations that are responsible for that?

Not much help but the same effect with a much older gmic (2.1.5) I had hanging about.

Using the recent gmic 2.4.2 same effect. I tried those images as png's same effect

Strangely, exported as ppm (raw) images from Gimp and gmic worked as expected. Make what you can of that

example: https://i.imgur.com/6WSYVpr.jpg

edit: I think it is something to do with the embedded color profiles, putting the images to basic Gimp greyscale and exporting to new jpeg's seems to work.

Thanks, I'll eventually investigate somewhat more.

That's weird, I think one of the images (Aquaman, I'm guessing that's him) got the effect of a red "multiply" layer for you but not for me.

Funnily enough I even tried converting to PNGs (imagemagick), I'd think that whatever information/data along the lines of color-profile would be lost by default, but apparently there needs to be some more explicit command to lose "whatever" that causes it.

Hello,
The command 'montage' actually assumes all your images have the same number of channels, which is not the case with your images (at least one has only a single channel, maybe a gray-valued png).
I suggest you force all your images having the same number of channels before invoking 'montage' :

gmic *.jpg -to_colormode 0 -montage A -o montage.jpg

I will add this directly in the 'montage' command to avoid this kind of issues in the future (see commit : https://framagit.org/dtschump/gmic/comm ... d0122d572e)

Thanks for noticing this !

I have used white before and not noticed a problem...but have only used black recently if anything at all.