There is a filter for GIMP: https://registry.gimp.org/node/24636 Description: "This plugin removes low frequency brightness and color differences from image. It's dedicated for creating textures for computer graphic from photos. But it shuld be usefull for other puroses too" Then, this filter is very useful to normalize the lights and colors in an image, and then to generate seamless textures with tiles from that image. This is also very useful to texture in Blender 3D, and it would be great to have a similar filter in Krita. Thank you!
By the way, you can find a working filter version for GIMP 2.8 in the next link: http://blenderartists.org/forum/showthread.php?346606-Software-Photoshop-Gimp-Plugin-for-Seamless-textures
Setiing this to wishlist :)
WISHGROUP: Larger Usability Fixes
Since the gimp link doesn't work anymore. The whole website is moved to the github repository. Some examples: https://github.com/pixlsus/registry.gimp.org_static/blob/master/registry.gimp.org/files/LF_Even_preview_brick.gif https://github.com/pixlsus/registry.gimp.org_static/blob/master/registry.gimp.org/files/LF_Even_preview_gravel.gif Filter itself: 2.0-2.6.x: https://github.com/pixlsus/registry.gimp.org_static/blob/master/registry.gimp.org/files/Low_Frequency_Even_2.x.scm >2.7x: https://github.com/pixlsus/registry.gimp.org_static/blob/master/registry.gimp.org/files/Low_Frequency_Even_2.7.scm