This program applies a speclowpass or blurring filter to a cube. An NxM
boxcar is moved through the cube and average of the boxcar at each position
is computed. This average, which effectively blurs the data, is written to
the output cube. In general, the larger the boxcar the more the output cube
is blurred. For example, a 101x101 boxcar will cause more blurring than a
3x3 boxcar.
This is the total number of bands 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.
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
the average.
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 the average.
This configuration creates a relatively small filter, resulting in a
slight amount of blurring.
GUI Screenshot
speclowpass gui
Example GUI
Screenshot of the GUI set to filter all pixels for the image using
a three by three boxcar. Note that as many of the default
parameters as are allowed are being used.
Input Image
The image before the filter
Input image before the speclowpass filter.
Parameter Name:
FROM
Here we see the original cube. The areas of greatest interest are
those with a great deal of contrast such as edges.
Output Image
The image after the filter
Output image after speclowpass
Parameter Name:
TO
After the filter, the entire image is somewhat softer. The difference
may be hard to detect on uniform areas, but the sections of the
image that previously were sharply contrasted are now blurred. As
this particular configuration has been set for a small filter, the
results are obtained quickly and are more subtle than a large filter.
Example 2
Running a 21x21 boxcar on all pixels
Description
The speclowpass filter is used again here, but at a much more intense level
This configuration creates a relatively large filter, resulting in a
great amount of blurring.
GUI Screenshot
speclowpass gui
Example GUI
Screenshot of the GUI set to filter all pixels for the image using
a 21 by 21 boxcar. This configuration will be slightly slower than
in the previous example, due to the increased boxcar size.
Input Image
The image before the filter
Input image before the speclowpass filter.
Parameter Name:
FROM
Here we see the original cube. The areas of greatest interest are
those with a great deal of contrast such as edges.
Output Image
The image after the filter
Output image after speclowpass
Parameter Name:
TO
As seen here, the 21 by 21 boxcar blurs the image to a great extent.
In fact, there seems to be little purpose for ever using a square
boxcar this large, except for the purpose of illustrating the effect
of the speclowpass.
