"Aubrey McIntosh, Ph.D." wrote in
message ...


George wrote:
""Nick Müller"" wrote in message
...


Hot pixels is a known problem of all CCD cameras during long exposures
(1s and up)
A hot pixel is created by an element with a higher rate of charge
leakage than its neighbors.
On long exposure the leakage may cross the exposed value treshold thus
producing a white dot on the image. BlackFrame NR uses a black-frame
method to remove such noise with preserving all details, so the makers
say. I haven't used this program, although I do have a copy. I have
used black frames many times in astrophotography to remove hot pixels.

Recently, in group s.e.d, there was a link to a site on spatial
filtering. It shows some examples of hot spot removal.

http://www2.polito.it/ricerca/cgvg/teaching/ComputerVision/SpatialFiltering.pdf

Thanks for the link. Always looking for enhancement technics.