Arithmetic Operators:

Demo
The arithmetic operator demo operates on two source images to produce a third resultant image. In this case, the top color image is combined with a gray scale mask image. When the buttons are pressed, the resultant image will be displayed below the source images. Options for addition, subtraction, multiplication, and division of two images are activated using the provided buttons.

JAI
Support is provided for both monadic and dyadic arithmetic operators. The monadic arithmetic operations include per-band addition, subtraction, multiplication, and division between a source image and a constant value which produce a destination image. The dyadic arithmetic operations include per-band addition, subtraction, multiplication, and division between two source images to produce a destination image. It is also possible to take the absolute value of pixels in the source image and store the results in a destination image. Exponentiation is also provided.

The arithmetic operations require that both source images and the destination image have the same data type and number of bands. The dimensions of the two images (height and width), however, need not be the same.

When operations are performed, origin locations for each image or single image for monadic operations are aligned. For example, for image addition the value at location 0,0 in one source image is added to location 0,0 of the second source image and the result is stored in location 0,0 of the destination image. This procedure is repeated for every pixel. Arithmetic operations on multi-band images are performed on corresponding bands in the source images.

Theory
Arithmetic operations are used to perform a pixel by pixel combination of two images. A single constant may be used to represent a "constant image."