ED - Edge Detection

PURPOSE

Detects edges using a Wiener-Filtering approach. The input image is processed with a recursive filter, and the filtered version is stored in a scratch file. The scratch file is subsequently searched for continuous lines along which the density variation exceeds a certain threshold. The resulting cartoon image is written into the output file.   Example.

USAGE

.OPERATION: ED

.INPUT FILE: PIC001
[Enter name of input image for filtering and edge detection.]

.OUTPUT FILE: EDG001
[Enter name of file where edge contours are to be put.]

.FILTER NUMBER (1/2/3/4): 1/2/3/4
[Specify one of the standard Wiener filters to be used.]

These four filters roughly correspond to the following situations: 1. Very high S/N ratio 2. Medium S/N ratio, many edges expected 3. Medium S/N ratio, fewer edges expected 4. Low S/N ratio

.THRESHOLD (1)LOW/(2)MEDIUM/(3)HIGH: 1/2/3
[Enter threshold option. Options 1, 2, and 3 have decreasing sensitivity but increasing stability against noise.]

NOTES

1. contact: JF

SUBROUTINES

EDGE

CALLER

UTIL3