USGS MIPS Stdflt Documentation

USGS MIPS Stdflt Documentation

This program applies a convolution filter to an image . The filter operator is the standard deviation of a NxM window. The output range of the filter is 0 to 127. However, the standard deviation is usually small, less than 20, so the result is multiplied by 10.

Files

This program requires as input an unsigned 8-bit , signed 16-bit , or /A>32-bit floating point image file and will produce the same type image file. The following information is transferred from the input file to the output file(if appropriate):

Image labels
Mosaic labels
Projection labels
Sonar labels
Navigation file
History file

Parameters

NL and NS: These parameters are used to define the size of the window to filter. They must be odd positive integers and do not have default values. The size of the window does not affect the speed of the program, so a 101x101 filter runs nearly the same speed as a 3x3 filter.
LOW and HIGH: These parameters are used to define valid DNs . Pixels whose DNs fall outside the range of LOW/HIGH will not be used when computing the standard deviation of the window. The defaults are the extremes based on the input image type, 0 and 255 for unsigned 8-bit images, -32768 and 32767 for signed 16-bit images, etc.
MULT: This parameter is used to scale the results of the filter. The output range of the filter is 0 to 127, however, the standard deviation is usually small, less than 20, so the result is multiplied by this factor. The default value is ten for unsigned 8-bit and signed 16-bit, and one for 32-bit floating point images.

Uses

This program can be used to examine the texture/spatial variability of an image because the standard deviation is directly related to the variance. Since the window size is adjustable, local to regional spatial variability information can be extracted.

Examples

From left to right, Landsat MSS Band 6, 3x3 standard deviation filter, and 21x21 standard deviation filter.

[Example Image]