IMAGE commands
PROGRAM NAME
imedian - Median Filter for Image Data
DESCRIPTION
imedian
performs median filtering on image data. The method is as follows:
for each WSIZExHSIZE window in the image, replace the pixel
at (WSIZE/2)x(HSIZE/2) (integer arithmetic) with the median of
the values in the window. The median is computed by
sorting the values in the window with quicksort and
extracting the middle value as the median. This is
not the fastest approach for BYTE data where a
histogram updating method could be used. It is, however,
extensible to higher data types including floating
point data.
If a map is present, the data is mapped prior to operation. Mask data is
ignored.
This implementation processes the image data by full planes.
Boundaries are handled by zero padding.
REQUIRED ARGUMENTS
- -i
-
type: infile
desc: Input image
- -o
-
type: outfile
desc: Output image
OPTIONAL ARGUMENTS
- -wsize
-
type: integer
desc: Width of window
default: 3
bounds: value > 0
- -hsize
-
type: integer
desc: Heigth of window
default: 3
bounds: value > 0
- -reps
-
type: integer
desc: number of repetitions of filter to perform
default: 1
bounds: value >= 0
EXAMPLES
SEE ALSO
RESTRICTIONS
Complex data types are not supported.
The ability to process by partial planes will be added at a future time,
permitting more efficient operation on images large in the W and H dimensions.
At some point, the faster histogram updating technique should be stolen from
K1.5 lvhmed(3) and put in place for BYTE processing.
REFERENCES
COPYRIGHT
Copyright (C) 1993 - 1997, Khoral Research, Inc. ("KRI") All rights reserved.