Subtracts a reference image from another image and outputs the difference.
image: Input image
reference: Reference image that will be subtracted from input images. A run-time error will occur if the type or size of the reference is not the same as that of the input.
allowNegativeGray: If this flag is
trueand the input images are both gray-level images, the output image will be signed 32-bit ints. Otherwise, the type of the output will be the same as that of the input.
abs(image - reference)(when
image - reference(when