This routine calculates the Laplacian of the supplied
, and subtracts it from the original array to create the output
NDF. The subtractions can be done a specified integer number of times. This operation
can be approximated by a convolution with the kernel:
where N is the integer number of times the Laplacian is subtracted. This convolution is
used as a uni-directional edge detector. Areas where the input data array is
flat become zero in the output data array.
laplace in [number] out
IN = NDF (Read)
NUMBER = _INTEGER (Read)
Number of Laplacians to remove.
OUT = NDF (Write)
TITLE = LITERAL (Read)
The title for the output NDF. A null value will cause
the title of the NDF supplied for Parameter IN to be used instead.
laplace a 10 b This subtracts ten Laplacians from the NDF called
a, to make the NDF called b. NDF b inherits its title from a.