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USGS

Isis 3 Application Documentation


circle

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Trims data outside of a circle

Overview Parameters Example 1 Example 2 Example 3

Description

This program will trim (set to NULL) all pixels in an input cube which fall outside of a user defined circle. That is, given a sample/line coordinate and a radius, all pixels whose distance away from the input sample/line is further than the radius will be set to NULL. This program is useful for trimming global cubes collected by framing cameras. A global cube is one in which the limb of the planet/target body is visible and therefore the camera has taken a picture of space as well as the planet. Using this program you can ensure the space pixels are NULL. This can be done by determining the sub-spacecraft point in sample/line coordinates and the radius of the body. Note that the sample/line position does not have to be within the image in question.

Categories


History

Kay Edwards1986-02-03 Original version
Jeff Anderson2002-06-19 Ported to Isis 3.0
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
Steven Lambright2008-05-12 Removed references to CubeInfo

Parameter Groups

Files

Name Description
FROM Input cube to trim
TO Output cube

Circle Definition

Name Description
SAMPLESample coordinate of circle
LINELine coordinate of circle
RADIUSRadius of the circle
X

Files: FROM


Description

Use this parameter to select the filename. All bands within the file will be trimmed.

Type cube
File Mode input
Filter *.cub
Close Window
X

Files: TO


Description

This file will contain the results of the circle trim.

Type cube
File Mode output
Close Window
X

Circle Definition: SAMPLE


Description

This defines the sample coordinate at the center of the circle. It can be negative or greater than the number of samples in the cube.

Type double
Internal Default Middle sample
Close Window
X

Circle Definition: LINE


Description

This defines the line coordinate at the center of the circle. It can be negative or greater than the number of lines in the cube.

Type double
Internal Default Middle line
Close Window
X

Circle Definition: RADIUS


Description

This defines the radius of the circle. Pixels outside the radius of the circle centered at (SAMPLE,LINE) will be trimmed. The default value is the lesser of half the samples or half the lines.

Type double
Internal Default Half the image size
Minimum 1.0 (inclusive)
Close Window

Example 1

Taking all defaults

Description

This example shows the result of taking all the default parameters on the application circle. line and samp defaulted to the center of the image, and radius defaulted to the minimum of nl/2.0 and ns/2.0

Command Line

circle from=circle_in to=circle1_out
line and sample default to the center of the image, radius defaults to the lesser one half of the number of lines or the number of samples

GUI Screenshot

Circle GUI

Example GUI

Screenshot of GUI with parameters filled in to perform the default circle operation

Input Image

Input image

Input image for circle

Parameter Name: FROM

This is the input image for the default example of circle.

Output Image

Output image showing results of the circle application defaults

Output image for circle

Parameter Name: TO

This is the output image for circle. Notice the NULL values in the corners of this image.


Example 2

Small centered circle

Description

This example shows the result of setting a smaller radius than the minimum of ns/2.0 and nl/2.0. The center of the circle defaults to the center of the image

Command Line

circle from=circle_in to=circle_out rad=150
line and sample default to the center of the input image, with a radius of 150 pixels

GUI Screenshot

Circle GUI

Example GUI

Screenshot of GUI with parameters filled in to perform a circle operation with a radius of 150

Input Image

Input Image

Input image for circle

Parameter Name: FROM

Input image

Output Image

Output image showing results of the circle application with a user defined radius

Circle radius smaller than image

Parameter Name: TO

Output image for circle radius = 150 on a 500 by 500 image


Example 3

Off centered

Description

This example shows the result of circle when the radius center is placed at the center of the upper right quadrant of the image. The radius is large enough to include data not in the immage.

Command Line

circle from=circle_in to=circle2_out line=125 samp=375 rad=200
the center of the circle is line 125 and sample 375, with a radius of 200

GUI Screenshot

Circle GUI

Example GUI

Screenshot of GUI with parameters filled in to perform a circle operation with a radius of 200 and centered on line/sample 125/375

Input Image

Input image

Input image for circle

Parameter Name: FROM

This is the input image for the default example of circle.

Output Image

Output image showing results of the circle application with all parameters defined

Output image off centered example of circle

Parameter Name: TO

This is the output image for circle. Notice the NULL values of this image.