ImageMagick Crib Sheet

• To merge greyscale files A and B to make a colour image, so that A is magenta and B is green to form C, do composite -compose CopyGreen A B C. If you want green-red, you need to somehow blank the blue channel.
• To tile a number of images into a grid, rock the montage command (a whole new command!). montage A.png B.png C.png D.png output.png does it; montage picks a squarish grid and lays them out in a conventional raster order. With a massive border - add -geometry +0+0 to suppress this entirely. Do -tile WxH, for some values of W and H, to control the shape of the grid.