ISIS Application Documentation
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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.
CategoriesRelated Applications to Previous Versions of ISISThis program replaces the following application existing in previous versions of ISIS:
Related Objects and DocumentsApplicationsHistory
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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 |
Parameter GroupsFiles
Filter Type
Boxcar Size
Boxcar Restrictions
Special Pixels
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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 |
The resultant filtered cube
Type | cube |
---|---|
File Mode | output |
Pixel Type | real |
The output of the filter operation is either the variance value or the standard deviation value.
Type | string | |||||||||
---|---|---|---|---|---|---|---|---|---|---|
Default | VARIANCE | |||||||||
Option List: |
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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 |
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 |
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 |
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 |
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) |
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 |
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 |
Example 2run svfilter Description
This example shows an svfilter operation using variance.
Command Line
svfilter fr=../IN/peaks.cub:4 t=OUT/svfilter.var fi=v s=5 li=5
svfilter a Terra image. Use VARIANCE filter. (fi=v)
GUI Screenshot
Input Image
Output Image |
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 |