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ISIS 2

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ISIS Application Documentation


svfilter

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Apply a variance or standard deviation filter to a cube

Overview Parameters Example 1 Example 2

Description

This program applies either a variance or standard deviation filter to a cube. The standard deviation filter is simply the square root of the variance and is selected by setting the FILTER parameter to STDDEV.

Categories


Related Applications to Previous Versions of ISIS

This program replaces the following application existing in previous versions of ISIS:
  • boxfilter

Related Objects and Documents

Applications


History

Eric Eliason1988-05-20 Original version
Tracie Sucharski2002-08-13 Ported to Isis 3.0
Jeff Anderson2002-11-26 Fixed bug which disallowed the standard deviation filter
K Teal Thompson2002-12-03 Add examples.
K Teal Thompson2003-03-28 Make images smaller.
Stuart Sides2003-04-04 Fixed problem with isiscvs not checking in the thumb and image directories.
Kim Sides2003-05-13 Added application test
Stuart Sides2003-05-16 Modified schema location from astogeology... to isis.astrogeology..."
Stuart Sides2003-07-29 Modified filename parameters to be cube parameters where necessary

U.S. Department of the Interior | U.S. Geological Survey
ISIS | Privacy & Disclaimers | Astrogeology Research Program
To contact us, please post comments and questions on the USGS Astrogeology Discussion Board
To report a bug, or suggest a feature go to: ISIS Github
File Modified: 02/21/2025 20:06:06
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Files: FROM


Description

Input cube to filter

Type cube
File Mode input
Filter *.cub
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Files: TO


Description

The resultant filtered cube

Type cube
File Mode output
Pixel Type real
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Filter Type: FILTER


Description

The output of the filter operation is either the variance value or the standard deviation value.

Type string
Default VARIANCE
Option List:
Option Brief Description
VARIANCE Perform variance filter This will output the variance at the center of the boxcar.
STDDEV Perform standard deviation filter This will output the standard deviation at the center of the boxcar.
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Boxcar Size: SAMPLES


Description

This is the total number of samples in the boxcar. It must be odd and can not exceed twice the number of samples in the cube. In general, the size of the boxcar does not cause the program to operate significantly slower.

Type integer
Minimum 1 (inclusive)
Odd This value must be an odd number
Close Window
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Boxcar Size: LINES


Description

This is the total number of lines in the boxcar. It must be odd and can not exceed twice the number of lines in the cube. In general, the size of the boxcar does not cause the program to operate significantly slower.

Type integer
Minimum 1 (inclusive)
Odd This value must be an odd number
Close Window
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Boxcar Restrictions: LOW


Description

Valid minimum pixel value that will be used in boxcar computation. If a pixel value is less than LOW then it will not be used when computing boxcar statistics.

Type double
Internal Default Use all pixels
Less Than HIGH
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Boxcar Restrictions: HIGH


Description

Valid maximum pixel value that will be used in boxcar computation. If a pixel value is greater than HIGH then it will not be used when computing boxcar statistics.

Type double
Internal Default Use all pixels
Greater Than LOW
Close Window
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Boxcar Restrictions: MINIMUM


Description

This is the minimum number of valid pixels which must occur inside the NxM boxcar for filtering to occur. For example, 3x5 boxcar has 15 pixels inside. If MINIMUM=10 then the filter will occur if there are 10 or greater valid pixels. A valid pixel is one that is not special (NULL, LIS, etc) and is in the range defined by LOW to HIGH.

Type integer
Default 1
Minimum 1 (inclusive)
Close Window
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Special Pixels: PROPAGATE


Description

This option is used to define how special pixels are handled. If the center pixel of the boxcar is a special pixel it will be propagated or set to NULL depending on the value of this parameter.

Type boolean
Default TRUE
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