ISIS Application Documentation
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Apply spectral low pass filter to a cube
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Name | Description |
---|---|
FROM | Input file |
TO | Filtered output cube |
Name | Description |
---|---|
BANDS | Number of bands in boxcar |
Name | Description |
---|---|
LOW | Minimum valid DN |
HIGH | Maximum valid DN |
Input cube to filter
Type | cube |
---|---|
File Mode | input |
Filter | *.cub |
The resultant filtered cube
Type | cube |
---|---|
File Mode | output |
Filter | *.cub |
This is the total number of bands in the boxcar. It must be odd and can not exceed twice the number of bands 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 the average.
Type | double |
---|---|
Internal Default | Use all pixels |
Less Than |
|
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 the average.
Type | double |
---|---|
Internal Default | Use all pixels |
Greater Than |
|
Example of usage of the spectral lowpass filter.
Example GUI Screenshot of the GUI wit h parameters set to perform the spechighpass filter with a 5 band boxcar on the image CM_1514302573_1.ir.cub. |
Input image spectral graph before speclowpass filter
Parameter Name:
FROM This is the spectral plot of the center point of the image, (32, 32), and shows all bands, 1- 256. No averaging has been applied, this is clear partialy because of th extreme peaks visible in the first half. The peaks are related to values which differ significantly from the bands around them. |
Output image spectral graph after being filtered
Parameter Name:
TO This is the image after the filter. Although there are still peaks, everything has been smoothed. In the before image the peaks were sharp where as now they are more curved. Differences have been leveled out to some extent. |
Example of usage of the spectral lowpass filter.
Example GUI Screenshot of the GUI with parameters set to perform the spechighpass filter with a 61 band boxcar on the image CM_1514302573_1.ir.cub. |
Input image spectral graph before speclowpass filter
Parameter Name:
FROM This is the spectral plot of the center point of the image, (32, 32), and shows all bands, 1- 256. No averaging has been applied, this is clear partialy because of th extreme peaks visible in the first half. The peaks are related to values which differ significantly from the bands around them. |
Output image spectral graph after being filtered
Parameter Name:
TO This is the image after the filter. As is very clear, the averaging has turned sharp peaks into a smooth slope and small bumps into nothing. All bands in the image are now muchmore similar to each ohter than they were before. Also note that the scale has changed significantly. |
Stacy Alley | 2008-09-02 | Original version |
Mackenzie Boyd | 2009-06-09 | Modified documentation, added exception handling for too many bands, modified examples |