MASKTOIM creates an image, showing which pixels are masked. Masked pixels are set to 0 in the image, while unmasked pixels are set to 1.
Use BOX=b to define the image size and location. This makes the new image have the size and location of box 'b'. See BOX for instructions for defining boxes.
You may also give the size and location of the new image with the keywords SR, SC, NR, and NC. NR and NC are required. If SR or SC are not given, they default to zero.
Any image already in the destination buffer is destroyed.