bef Documentation

BEF - Bit Error Filtering Program
PROGRAMMER:  MARS1::KEH (Ken Herkenhoff, Caltech)
Filters 8-bit images with less than 1250 samples per line, removing bit
errors by replacing bad values with the average of 10 pixels above.
Only previously filtered data are used in calculating the average.
Pixels are filtered only if their value differs from that of the previous
pixel by more that the input tolerance TOL.  BEF is designed to avoid
improper filtering of real data such as planetary limbs, but should be
used carefully in cases where large contrasts are expected.  The
tolerance TOL should be increased when filtering limb or satellite
images, for instance.  BEF assumes that the first and last few pixels
of each line are in the vidicon mask and therefore do not need to be
filtered.  The first two lines are filtered only minimally to assure that
the program is properly initialized.

Input image file name
(default extension is .cub)

NONE

Output image file name
(default extension is .cub)

NONE

Filter tolerance in DN

14

ADDITIONAL NOTES:

Parm	Description
FROM	The input image must be 8-bit with less than 1250 samples per line. Reseaux should be found before BEF is run on an image, as it will remove reseau marks. If the file extension is omitted, then ".cub" will be assumed.
TO	The output image will be 8-bit with noise removed. If the file extension is omitted, then ".cub" will be assumed.
TOL	The tolerance for the filter in DN. No filtering will occur if adjacent pixel values differ by less than TOL. The default tolerance of 14 will preserve real data contrasts in most planetary images. Larger tolerances should be used for limb or satellite images.