Arithmetic/Logic

Toolbar:

Menu:    Processing > Arithmetic/Logic…

Use this command to perform arithmetic and logic operations between two images or between an image and a constant value. When using arithmetic operators, the images are processed on a pixel-by-pixel basis. If the images differ in types, the image of the lower bit depth is converted to the higher one before applying the operation, however if one of the images is a color one, the other image will be converted to a color type even if it causes the loss of the bit depth. When applied to color images, the operations will be performed separately on all three channels. For complex images ImageWarp uses the complex arithmetic treating both Re and Im channels as horizontal and vertical components in 2D complex space and processing them in combination.

The arithmetic and logic operations are performed from the upper left corner of each image or, if the images have selections, from the upper left corner of the bounding box of each selection. If the images or selections are different sizes, the larger image or selection is clipped to match the smaller one before the operation is performed.

When you choose this command, the Arithmetic/Logic dialog box will appear with two tabs.
Select one of the following functions:

Arithmetic

Click… To… Invert invert pixel values in an image. Offset add a constant value to each pixel in an image. Factor multiply each pixel in an image by a constant value. Average find an average value for each pair of corresponding pixels in two images. Add add pixels in two images. Subtract subtract pixels of one image from pixels of another one. Multiply multiply pixels in two images. Divide divide pixels of one image by pixels of another one. Difference find absolute differences between pixels in two images. Combine apply a linear combination to pixels of two images. Minimum find a maximum for each pair of corresponding pixels in two images. Maximum find a minimum for each pair of corresponding pixels in two images.

Logic

Click… To… NOT perform logical NOT on each pixel of an image. AND perform bitwise AND between pixels in two images. OR perform bitwise OR between pixels in two images. XOR perform bitwise XOR between pixels in two images. NAND perform bitwise NAND between pixels in two images. NOR perform bitwise NOR between pixels in two images. XNOR perform bitwise XNOR between pixels in two images. LSHIFT apply bitwise left shift to pixels of an image. RSHIFT apply bitwise right shift to pixels of an image. Mask apply a phase mask to an image.