A script that makes GIMP reduce the canvas size to the selected layer.
download
Download the script. Also, the simple script is not a long read:
def canvas_to_layer(image, drawable): offset_x, offset_y = pdb['gimp-drawable-offsets'](drawable) offx = 0 - offset_x offy = 0 - offset_y pdb['gimp-image-resize'](image, drawable.width, drawable.height, offx, offy)
files related to subject
The downloadable version also contains a script that will discard not visible layers when merging. While GIMP can do this through the gui, it is not available to the pdb yet.