Isis 3 Application Documentation
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Reduce the pixel dimensions of an image
Description
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Groups
Examples
History
Name | Description |
---|---|
FROM | Input cube to reduce |
TO | Output cube |
Name | Description |
---|---|
ALGORITHM | Algorithm used to reduce image (Average,Nearest neighbor) |
MODE | Scale down the image or reduce to specific dimensions |
SSCALE | Sample scaling factor inverse |
LSCALE | Line scaling factor inverse |
ONS | Number of samples in output |
ONL | Number of lines in output |
VALIDPER | Valid percentage |
VPER_REPLACE | Replacement method when VALIDPER fails |
Use this parameter to select the filename. All bands within the file will be scaled down.
Type | cube |
---|---|
File Mode | input |
Filter | *.cub |
This file will contain the results of the shrunken cube.
Type | cube |
---|---|
File Mode | output |
Filter | *.cub |
This chooses the algorithm used to reduce the image. The possibilities are: average or nearest-beighbor.
Type | string | |||||||||
---|---|---|---|---|---|---|---|---|---|---|
Default | AVERAGE | |||||||||
Option List: |
|
Select between reducing the image to a proportion of the original (by a scaling factor inverse) or to specific dimensions (in terms of total number of pixels).
Type | string | |||||||||
---|---|---|---|---|---|---|---|---|---|---|
Default | SCALE | |||||||||
Option List: |
|
This is the scaling factor inverse for the sample direction. For example, SSCALE=4 will reduce the number of samples by 1/4th.
Type | double |
---|---|
Default | 1.0 |
Minimum | 1.0 (inclusive) |
This is the scaling factor inverse for the line direction. For example, LSCALE=4 will reduce the number of lines by 1/4th.
Type | double |
---|---|
Default | 1.0 |
Minimum | 1.0 (inclusive) |
The number of samples desired in the output cube. This value must be less than or equal to the number of samples in the input image.
Type | integer |
---|---|
Minimum | 1 (inclusive) |
The number of lines desired in the output cube. This value must be less than or equal to the number of lines in the input image.
Type | integer |
---|---|
Minimum | 1 (inclusive) |
This parameter specifies what percentage of the pixels need to be valid (non-special pixels). For example, scaling down by a factor of two results in a 2x2 window (four pixels) being reduced to one pixel. If VALIDPER is set at 50, then at least two pixels of the four must be valid (50%). If this criteria is met, the resulting value of the output pixel will be the average of the valid input pixels. Otherwise the output pixel will be set to the input pixel which is closest to the center of the window.
Type | double |
---|---|
Default | 50 |
When the set VALIDPER variable is not met, this is how the pixel with be filled.
Type | string | |||||||||
---|---|---|---|---|---|---|---|---|---|---|
Default | NULL | |||||||||
Option List: |
|
Reduce the number of samples by a factor inverse of 2, while leaving the number of lines the same
Example GUI Screenshot of the GUI with parameters set to perform a sample reduction by scaling. |
Input image for reduce
Parameter Name:
FROM This is the image as it was taken originally. |
Output image for reduce
Parameter Name:
TO The reduced image. Though it has been scaled down so that it can be viewed in a web browser, the essential change can still be observed. The vertical distortion is noticable, and the output cube is 1/2 the size of the input cube. |
Reduce the number of samples to 150, and the number of lines to 250
Example GUI Screenshot of the GUI with parameters set to perform a sample and line reduction to a total number of pixels. |
Input image for reduce
Parameter Name:
FROM This is the image as it was taken originally. |
Output image for reduce
Parameter Name:
TO The reduced image. Though it has been scaled down so that it can be viewed in a web browser, the essential change can still be observed. The vertical and horizontal distortion is noticable, and the output cube has 1/3 the number of samples and 1/2 the number of lines as the input cube. |
Jeff Anderson | 1995-11-06 | Original version |
Tracie Sucharski | 2002-10-12 | Ported to Isis 3.0, Separated magcube into reduce and enlarge. |
Tracie Sucharski | 2003-05-13 | Read in ons/onl as integers not doubles. |
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 |
Jeff Anderson | 2004-07-14 | Fixed propagation bug |
Tracie Sucharski | 2004-07-15 | Forget to change ons/onl minimum inclusive values from 1.0 to 1 during the 2003-5-13 change. |
Drew Davidson | 2005-08-17 | Added example |
Tracie Sucharski | 2006-04-03 | Fixed bug in average algorithm, forgot to divide Vper by 100. |
Jeff Anderson | 2006-09-19 | Fixed problems when program ran in batchlist |
Sean Crosby | 2007-02-28 | Program now updates output file's mapping keywords |
Steven Koechle | 2008-01-23 | Changed so if it failed VPER the output cube would get null values. Now processes cube bands from user input correctly |
Steven Lambright | 2008-05-13 | Removed references to CubeInfo |
Steven Koechle | 2008-05-15 | Added radio button for VPER options to allow original functionaliy. |
Steven Lambright | 2008-12-22 | The "Scale" keyword in the Projection group in the labels is now being updated if this program is run on a projected cube. |
Mackenzie Boyd | 2009-09-03 | Added keyword REDUCTION_TYPE to allow for clear switching between ons, onl and sscale, lscale. Fixed problem involving cube remaning open after an exception. |
Janet Barrett | 2009-10-22 | Now uses the SubArea class to produce output cube labels with corrected Mapping, Instrument, and AlphaCube groups. |
Travis Addair | 2009-11-12 | Improved documentation, changed parameter names, and updated examples. |
Travis Addair | 2009-12-09 | Updated documentation and changed parameters STOTAL and LTOTAL back to ONS and ONL, respectively. |
Sharmila Prasad | 2011-04-26 | Ported the reduce by near and average functionality from the app to base/objs/Reduce class |
Sharmila Prasad | 2011-10-07 | Fixed bug #0000463 regarding memory leak |