This program will apply a Sobel or Roberts gradient filter to a cube.
These gradient filters will highlight edges of the image. The output
contains the estimated, absolute magnitude of the spatial gradient of the
input cube.
NOTE: Any time a calculation must be done where one or more values are
special pixels, the output will simply be NULL. If this causes unexpected
results, you may need to run stretch to change input special pixels to
something that is appropriate for calculation. For example, if the image
contains a number of HIS values, you may want to stretch these to 255
prior to running the gradient filter.
This example shows the use of the roberts filter in order to highlight
edges
GUI Screenshot
gradient gui
Example GUI
Screenshot of the GUI with parameters set to filter using a roberts
gradient
Input Image
The image before the filter
Input image before the filter.
Parameter Name:
FROM
This is the image as it was taken originally.
Output Image
The image after the filter
Output image after the roberts gradient
Parameter Name:
TO
The use of the Roberts gradient here creates an output image which
helps to highlight the edges. Since the Roberts filter uses a smaller
boxcar, less of the image is taken into consideration at each processing
step and thus the image can be created faster. The tradeoff is that images
that have had the Roberts gradient applied tend be effected more by noise
in the image.
