ISIS Application Documentation
histeq | Printer Friendly View | TOC | Home |
Apply histogram equalization to a cube.
| Overview | Parameters | Example 1 |
Description
This program equalizes the histogram of an input cube (defined by FROM), and outputs the results to a file (defined by TO).
By equalizing the input file's histogram, the resulting cumulative distribution becomes linear instead of curved. The following is an illustration of what happens to an input file. The blue line represents the histogram and the red line is the cumulative distribution. On the left is the histogram and cumulative distribution of an unmodified image, while the figure on the right shows how the both the histogram and distribution are altered. 
 The blue line represents the input file's histogram and the red line represents its cumulative distribution function. CategoriesRelated Objects and DocumentsApplicationsHistory
|
| 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 19:28:11 |
Parameter GroupsFiles
Histogram Options
|
| 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 19:28:11 |
Files: FROM
Description
This file will have its cumulative distribution reshaped to be more linear.
| Type | cube |
|---|---|
| File Mode | input |
| Filter | *.cub |
Files: TO
Description
The resultant cube containing a linearized image
| Type | cube |
|---|---|
| File Mode | output |
| Filter | *.cub |
Histogram Options: MINPER
Description
Minimum DN cut-off value at the cumulative percent of the histogram
| Type | double |
|---|---|
| Default | 0.5 |
| Minimum | 0.0 (inclusive) |
| Less Than | MAXPER |
Histogram Options: MAXPER
Description
Maximum DN cut-off value at the cumulative percent of the histogram
| Type | double |
|---|---|
| Default | 99.5 |
| Maximum | 100.0 (inclusive) |
Histogram Options: INCREMENT
Description
Percentage increment for the histogram
| Type | integer |
|---|---|
| Default | 1 |
| Minimum | 1 (inclusive) |
| Less Than | MAXPER |
Example 1Histogram equalization Description
This example shows the results of histogram equalization on a single band of an image.
Command Line
histeq
from=../peaks.cub+6 to=../result.cub
Use histogram equalization to the make the input cube's sixth band distribution function linear.
GUI Screenshot
Input Images
Output Images
|
![Histeq Gui](javascript:popUpNewWindow ("assets/image/histeqgui.jpg",500, 500))
![Input Peaks (band 6) Image](javascript:popUpNewWindow ("assets/image/FROMparameter.jpg",500, 500))
![Input Peaks (band 6) Image](javascript:popUpNewWindow ("assets/image/band6plot.jpg",500, 500))
![Output image showing the result of the histogram equalization.](javascript:popUpNewWindow ("assets/image/TOparameter.jpg",500, 500))
![Output image](javascript:popUpNewWindow ("assets/image/toplot.jpg",500, 500))
| 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 19:28:11 |