So I have roughly 400 images of two hands doing gestures. The hands never get connected. I do need to remove the left hand from the image without changing the resolution or size of image and basically would need to make the black color the same gray as background. What are my best options to do so? Here's four examples of the images I have in my dataset:

closed as off-topic by David Foerster, Charles Green, Kaz Wolfe, Eric Carvalho, mikewhatever Sep 29 '17 at 5:15

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  • That requires computer vision techniques which is imho a little beyond the more or less simple image processing questions that are on topic on Ask Ubuntu. I recommend that you ask your question on Computer Graphics or Stack Overflow. – David Foerster Sep 27 '17 at 7:52
  • I guess you want to do it automatically. If fully automatic, I have the same suggestion as @DavidFoerster. If you want to do it semi-automatically, maybe you can use imagemagick by manually selecting where to apply the mask (how big fraction of the image to cover from the left edge) to cover the left hand, if enough with one dimension. (You can do it manually with gimp, but with 400 pictures it would be a lot of boring manual operations.) – sudodus Sep 27 '17 at 8:11
  • This question seems OK to me although otoh out of cowardice I asked a somewhat similar question (about GIMP, not ImageMagick) on Graphics Design Stack Exchange instead of here and it got answered there. – karel Sep 27 '17 at 8:47
  • @karel: Could you please provide a link to that question? I can't find it in your activity log. – David Foerster Sep 27 '17 at 9:01
  • Link: graphicdesign.stackexchange.com/questions/67173/… In case this is confusing I'm trying to learn how to automate the process of editing boot screen photos in order to save time when editing these images in GIMP. – karel Sep 27 '17 at 9:18