vsub(1)

PROGRAM
vsub - Compute the difference (subtract) between two images pixel by pixel.

SYNTAX

vsub

-i1 first input image

-i2 second input image

-o  resulting output image

[-m]
    subtraction operation masking image

[-V]
    Gives the version for vsub

[-U]
    Gives the usage for vsub

[-P]
    Prompts for command line options

[-A [file1]]
    Creates the answer file called vsub.ans or file1

[-a [file1]]
    Uses vsub.ans or file1 as the answer file

DESCRIPTION
vsub computes the difference between the first input image and the second input image (result = image1 - image2), with an optional operation gating image.

The two input images must be of the same size and have the same number of data bands, as must the optional mask image. The input images may be of the same or different data types. If the input images are of different data types, then all input images will be upcast to the highest input image data type. The output image data type will be the same as that of the highest data type of the input images.

The optional mask (gating) image will be upcast to the highest data type of the input images. The mask image is used to gate the operation. A non-zero mask pixel enables the output pixel to contain the result of the division. A zero mask pixel just transfers the value of the corresponding pixel in the first input image to the output pixel.

REQUIRED ARGUMENTS

-i1 type: infile
    desc: first input image

-i2 type: infile
    desc: second input image

-o  type: outfile
    desc: resulting output image

OPTIONAL ARGUMENTS

-m  type: infile
    desc: subtraction operation masking image

EXAMPLES
vsub -i1 input.image1 -i2 input.image2 -o output.image -m mask.image

This subtracts input.image2 from input.image1 using a mask image and stores the results in output.image.

SEE ALSO
intro(1), verror(3), vgparms(3), vutils(3), lvsub(3) vcast(1)

RESTRICTIONS
vsub will not operate on:
    Bit
data storage types.

COPYRIGHT
Copyright 1991, University of New Mexico. All rights reserved.