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ISIS Application Documentation

sharpen

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Sharpen the features in a cube

Description
Categories
Groups
Examples
History

Description

This program sharpens the edges in the image. The method for sharpening is done by applying a high pass filter to a cube and adding the filter results back to the original image. In general, you will sharpen small features with smaller boxcars and larger features with larger boxcars.

Categories

Related Applications to Previous Versions of ISIS

This program replaces the following application existing in previous versions of ISIS:

Related Objects and Documents

Applications

Parameter Groups

Files

Name Description
FROM Input file
TO Output highpass cube

Boxcar Size

Name Description
SAMPLES Number of samples in boxcar
LINES Number of lines in boxcar

Boxcar Restrictions

Name Description
LOW Valid minimum pixel
HIGH Valid maximum pixel
MINIMUM Minimum boxcar pixel count

Other

Name Description
PROPAGATEPropagate special pixels

Files: FROM

Description

Input cube to filter

Type cube
File Mode input
Filter *.cub

Files: TO

Description

The resultant filtered cube

Type cube
File Mode output

Boxcar Size: SAMPLES

Description

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
Default 3
Minimum 1 (inclusive)
Odd This value must be an odd number

Boxcar Size: LINES

Description

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
Default 3
Minimum 1 (inclusive)
Odd This value must be an odd number

Boxcar Restrictions: 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 boxcar statistics.

Type double
Internal Default Use all pixels
Less Than
  • HIGH

Boxcar Restrictions: 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 boxcar statistics.

Type double
Internal Default Use all pixels
Greater Than
  • LOW

Boxcar Restrictions: MINIMUM

Description

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)

Other: PROPAGATE

Description

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

Examples

Example 1

3x3

Description

Use a 3x3 boxcar

Command Line

sharpen f=peaks.cub:4 t=sharpen
In this example the boxcar size is the default 3 by 3.

GUI Screenshot

Sharpen Gui

Example Gui

Screenshot of GUI with parameters filled in to perform a "sharpen"ing of the input image with the default boxcar of 3x3.

Input Image

Input image

Input image for sharpen

Parameter Name: FROM

This is the input image for the sharpen example.

Output Image

Output image showing results of the sharpen application.

Output image for sharpen

Parameter Name: TO

This is the output image for this example of sharpen. Notice the edges of features are sharper. It is the same as running highpass and adding the highpass output back to the input image.

History

Eric Eliason1988-05-20 Original version
Jeff Anderson2002-09-25 Ported to Isis 3.0
K Teal Thompson2003-04-10 Add example.
Kim Sides2003-05-13 Added application test
Stuart Sides2003-05-16 Modified schema location from astogeology... to isis.astrogeology..."
Stuart Sides2003-07-29 Modified filename parameters to be cube parameters where necessary
Jeff Anderson2004-02-17 Removed addback option and put it in the highpass program