ISIS Application Documentation
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Compute interpolations to replace special pixels.
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Note: This application will not extrapolate DN values beyond the endpoints of a data set. For example, if you choose to fill gaps that run across lines, then any special pixel values in the first or last vertical column of the image will not be filled. If any of these are not in a corner, you can run fillgap again using the output of the first run as input and SAMPLE as the DIRECTION parameter. Corner pixels can be filled by using the specpix application or the lowpass filter application.
Name | Description |
---|---|
FROM | Input file. |
TO | Output file. |
Name | Description |
---|---|
INTERP | Interpolation type to be used on the line and sample transform |
Name | Description |
---|---|
DIRECTION | Direction of bad pixels |
Input file to be filled.
Type | cube |
---|---|
File Mode | input |
Filter | *.cub |
Output cube.
Type | cube |
---|---|
File Mode | output |
Filter | *.cub |
fillgap provides 3 different interpolation options. The interpolation option chosen is used to compute a continuous (or piecewise continous) interpolation so that each line and sample has a transform location that maps the output line and sample to a shifted input line and sample. These interpolations provide this mapping. This is done by collecting the known DN values for each line or sample column and using the chosen interpolation scheme to approximate the missing DN values (special pixels).
Type | string | ||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Default | CUBIC | ||||||||||||
Option List: |
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This is the direction of the special pixels across the image. If the special pixels run through the bands of the image data, try both directions to see which works best.
Type | string | ||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Default | SAMPLE | ||||||||||||
Option List: |
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Fill horizontal gaps of peaks image
Example Gui Screenshot of GUI with parameters filled in to perform a fillgap operation on the input image. |
Input image for fillgap
Parameter Name:
FROM This is the input image for the fillgap example with null horizontal line. |
Output image for fillgap
Parameter Name:
TO This is the output image that results after a cubic interpolation to fill the null data gaps. |
Fill gaps of Cassini ISS image
Example Gui Screenshot of GUI with parameters filled in to perform a fillgap operation on the input image. |
Input image for fillgap
Parameter Name:
FROM This is a Cassini ISS image that has been altered to include each type of special pixels on an edge of the image. |
Output image for fillgap
Parameter Name:
TO This is the output image that results after a cubic interpolation to fill the special pixel data gaps. Notice the special pixels that move across samples and touch edges are not filled. This includes the block of null pixels at the top left corner of the image. This happens because the valid data only does not exist on both sides of these gaps and extrapolation is not permited. However, the special pixels that touch the upper and lower edges are filled since these gaps move across lines. |
Fill gaps of Cassini ISS image
Example Gui Screenshot of GUI with parameters filled in to perform a fillgap operation on the input image. |
Input image for fillgap
Parameter Name:
FROM This is a Cassini ISS image that has been altered to include each type of special pixels on an edge of the image. Some of these pixels have already been filled by a previous run of fill gap (see Example 2). |
Output image for fillgap
Parameter Name:
TO This is the output image that results after a cubic interpolation to fill the special pixel data gaps. Notice all special pixels have been filled except the top left corner of the image. Special pixels in the corners of an image can not be filled by the fillgap application since they are beyond the endpoints of any known data values (i.e. DNs values of samples and lines). |
Stacy Alley | 2007-08-08 | based off slither - first version of fillgap |
Christopher Austin | 2008-01-30 | Changed INTERP option CUBIC's name to CUBICCONVOLUTION to correlate with other apps using the INTERP param. |
Jeannie Walldren | 2008-11-05 | Removed references to DataInterp class and replaced them with NumericalApproximation class. |
Jeannie Walldren | 2009-04-21 | Added an exception catch so the application may continue if the interpolation fails for some pixel. Added a message to the log to inform users how many pixels were not filled. Updated user documentation to explain what they may do if this occurs. Changed the INTERP parameter CUBICCONVOLUTION back to CUBIC since this application uses a cubic spline, not cubic convolution. Added test cases and documentation examples. |