The Resynthesizer plugin for GIMP has been in development since 2000, according to the documentation, though it closely resembles a feature Photoshop introduced back in 2011. Both tools can remove an object from an image by covering it with nearby textures. Resynthesizer can also take one sample of a texture and seamlessly fill a whole image with it.
Goal
Remove the two hiking boots from this image:
Walkthrough
- Select one of the boots somehow. I used the Scissors Select tool, which automatically aligns your selection to the edge of an object. You start by clicking anywhere on the boot's outline, and then continue to click around its outline. The line of your selection will fit itself to the best path between every two points, but if it missed, click the middle of the misplaced line and drag it to where it should be. Go in a circle and close the loop by clicking the first point you placed. Then hit Return to make it into a selection.
- Optional, helpful with shadows: Go to Select > Grow... in the menubar, and in the resulting window, type in a number over 50, click OK, and see how much bigger the selection gets. I wanted to get the selection boundary outside the shadow of the boot, so the next step wouldn't fill it with a dark texture. If 50 is too far or too short, go to Edit > Undo or hit the shortcut Command-Z, and try step 2 again. I grew the selection by 100 pixels.
- When you have the selection you want, go to Filters > Enhance > Heal selection... and in the window that pops up, type in a generous radius to take texture from. 100 was ideal for this image. This is the number of pixels outside your selection the program will go to search for textures. In the picture below, I didn't grow the selection or choose a large enough radius, and it filled the boot with a conspicuous dirt-like texture. Click OK and let it do its thing.
- Resynthesizer is a CPU-hungry process, GIMP is a slow program, and both these factors will make this process take a long time. 1 or 2 mysterious icons should pop up in your Dock, with names like "script-fu." These are processes GIMP is calling on to get the job done. If you force quit one of them, and I have done so before, options will disappear from your Filters menu, and you'll have to restart GIMP to get them back.
- When the loading screen disappears, GIMP may still take several seconds to draw your updated image. Be patient. If it doesn't look how you wanted, hit Undo and play around with the size of the selection or the radius to take the texture from.
Result
After applying the tool to both boots, they are effectively removed from the picture.
Learn More
A DuckDuckGo search turned up
this lengthy post by Pat David, which gives a much longer explanation of what the plugin will do. I didn't base my walkthrough on his post, but I'll probably refer back to it in the future.
