User's Guide

MASK

Applies polygonal masks to an image

Function:

Performs a masking of the input image using polygonal sites from a statistics file. The output image contains the input image pixel values within the polygons and a user-specified constant value outside the polygons. Boundary points are classified as inside the polygon.

Parameters:

IN

Input image to which the masking is applied. Image may be BYTE, INTEGER*2, INTEGER*4, or REAL*4.

INSTAT

Input statistics file containing polygonal sites to be used for masking.

OUT

Output image. It will have the same number of bands and data type as input image.

CLASSNAM(*)

Name of class containing polygonal sites. The mask contains all the polygons corresponding to all the sites in the specified class. Default: all classes are considered.

EXTER(0)

Constant pixel value for the region outside the polygons

Examples:

1. LAS> mask in=image1.dat instat=stat.dat out=image2.dat classnam=water

   A masking is performed on the input image, IMAGE1.DAT, using the polygons in the statistics file STAT.DAT for the class WATER. The output image, IMAGE2.DAT, contains a masked area from polygons for the class WATER, with the area outside the polygons having a uniform value of 0.

2. LAS> mask in=image.one instat=stat.dat out=image.two exter=255

   A masking is performed on the input image, IMAGE.ONE, using the polygons from STAT.DAT for all classes and sites. The area outside the polygons in the output image, IMAGE.TWO, has a uniform value of 255.

Description/Algorithm:

MASK is a procedure that uses the program INSERT for processing. See INSERT for more information.

Nonfatal Error Messages:

See INSERT for error messages.

Fatal Error Messages:

See INSERT for error messages.

User Notes:

None.