Added in 1.9.0
/drawsave -bNqN <@window> <filename>
Saves the background picture of the specified picture @window to a file.
-bN - allows you to specify the bit depth of the saved file, which can be 1, 4, 8, 16, 24, or 32.
-qN - allows you to specify the quality of the jpeg file that is being saved, where N is between 1 and 100.
<@window> - Window name to save from.
<filename> - Filename to save to.