ISIS Application Documentation
deriv | Standard View | TOC | Home |
Apply horizontal or vertical derivative
Description
Categories
Groups
Examples
History
Description
This program will apply a horizontal or vertical derivative to a cube. This will highlight edges in the image created by groups of contrasting DN values. The horizontal derivative utilizes a two sample by one line boxcar convolution for its solution, and will highlight horizontal linear changes. The vertical derivative utilizes a one sample by two line boxcar convolution for the output, and will highlight vertical linear changes. Please refer to the following 2 by 2 pixel example image:
In this image, the horizontal derivative for A would be:
A_NewDN = A - B
The vertical derivative for A would be:
A_NewDN = A - C
NOTE: If this program needs to do calculations where special pixels are involved, it will simply output NULL. If this causes undesireable results, you should run the image through the stretch program to change all special pixels to valid data. For example, if you have a number of HRS pixels, you might want to stretch those to 255 prior to running the deriv filter.
Categories
Parameter Groups
Files
| Name | Description |
|---|---|
| FROM | Input cube |
| TO | Output cube |
Derivative Direction
| Name | Description |
|---|---|
| DIRECTION | Direction of derivative |
Files: FROM
Description
Use this parameter to select the filename. All bands within the file will have the derivative applied.
| Type | cube |
|---|---|
| File Mode | input |
| Filter | *.cub |
Files: TO
Description
This is the output file.
| Type | cube |
|---|---|
| File Mode | output |
| Pixel Type | real |
Derivative Direction: DIRECTION
Description
This chooses the derivative direction. The possibilities are: HORZ which uses a 2x1 kernel and VERT which uses a 1x2 kernel.
| Type | string | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Default | HORZ | |||||||||
| Option List: |
|
Examples
Example 1
Horizontal
Description
Command Line
GUI Screenshot
Derivative Gui
|
Example Gui Screenshot of GUI with parameters filled in to perform a horizontal derivative of the input image. |
Input Image
Input image
|
Input image for deriv
Parameter Name:
FROM This is the input image for the horizontal direction option of deriv. |
Output Image
Output image showing results of the deriv application with direction: horizontal.
|
Output image for deriv
Parameter Name:
TO This is the output image for the horizontal example of deriv. The horizontal features fade and vertical features are enhanced. |
Example 2
Vertical
Description
Command Line
GUI Screenshot
Derivative Gui
|
Example Gui Screenshot of GUI with parameters filled in to perform a vertical derivative of the input image. |
Input Image
|
Input image
|
Input image for deriv
Parameter Name:
FROM This is the input image for the vertical direction option of deriv. |
Output Image
Output image showing results of the deriv application with direction: vertical.
|
Output image for deriv
Parameter Name:
TO This is the output image for the vertical example of deriv. The vertical features fade and horizontal features are enhanced. |
History
| Tracie Sucharski | 2002-12-24 | Original version |
| Tracie Sucharski | 2003-01-28 | Fixed application name in xml file, misnamed as gradient. |
| K Teal Thompson | 2003-04-10 | Added examples. |
| Kim Sides | 2003-05-13 | Added application test |
| Stuart Sides | 2003-05-16 | Modified schema location from astogeology... to isis.astrogeology..." |
| Stuart Sides | 2003-07-29 | Modified filename parameters to be cube parameters where necessary |
| Brendan George | 2005-11-07 | Modified to handle special pixels |
| Jac Shinaman | 2007-02-08 | Updated xml documentation with examples |