ISIS Application Documentation
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Apply a spectral high pass filter to a cube
| Overview | Parameters | Example 1 | Example 2 |
Description
This program applies a spectral high pass filter to a cube. The spectral
component means that this will be a high pass amongst the bands of an image
as opposed to averaging the lines and samples on the spacial plane with high
pass. A highpass filter involves subtracting a lowpass, the average, from
the original value.
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 19:28:14 |
Parameter GroupsFiles
Boxcar Size
Boxcar Settings
|
| 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 19:28:14 |
Files: TO
Description
The resultant filtered cube
| Type | cube |
|---|---|
| File Mode | output |
| Pixel Type | real |
| Filter | *.cub |
Boxcar Size: BANDS
Description
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 |
Boxcar Settings: 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 the average.
| Type | double |
|---|---|
| Internal Default | Use all pixels |
| Less Than | HIGH |
Boxcar Settings: 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 the average.
| Type | double |
|---|---|
| Internal Default | Use all pixels |
| Greater Than | LOW |
Example 1Example of usage of the spectral highpass filter. Description
This example shows a spectral highpass filter being applied to the image
with a 15 depth boxcar. This cube has 256 bands so 15 is relatively
small. Although no averaging is done within a single band, the averaging
of the pixels of many bands will cause some averaging and smoothing of
the image if there is much difference between bands. Here is an image
which highlights which pixels a single pass would average. The image
shows a 9x9 dot instead of a single pixel highlighted to make it more
visible. In this picture the boxcar would be seven or more bands, with
the output pixel being one of the visible pixels. Depending on how large
the boxcar was many of the values taken in could not be original, at a
minimum, one value will be mirrored since there are only six available
bands.
Command Line
spechighpass
from=/work1/salley/CM_1514302573_1.cub to=/work1/mboyd/postSHP.cub
bands=15
This example will filter the image using 15 bands and no limits on
high or low.
GUI Screenshot
Input Image
Output Image
|
![spechighpass gui](javascript:popUpNewWindow ("assets/images/specHgui.jpg",586, 475))
![The image graph before the filter](javascript:popUpNewWindow ("assets/images/preSHP.jpg",750, 336))
![The image graph after the filter](javascript:popUpNewWindow ("assets/images/postSHP.jpg",750, 336))
| 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 19:28:14 |
Example 2Example of usage of the spectral highpass filter. Description
In this example the spechighpass filter is used to filter an image using
a boxcar of size 63 and a high tolerance of .075 on a photo with 256
bands.
Command Line
spechighpass
from=/work1/salley/CM_1514302573_1.ir.cub to=/work1/mboyd/post63.cub
bands=63 high=.075
This example will filter the image using 63 bands and a high limit of
0.075.
GUI Screenshot
Input Image
Output Image
|
![spechighpass gui](javascript:popUpNewWindow ("assets/images/specHgui2.jpg",663, 478))
![The image graph after the filter](javascript:popUpNewWindow ("assets/images/post63.jpg",750, 336))
| 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 19:28:14 |