fixpix images badpixels
Bad pixel regions in the list of two dimensional images are replaced by linear interpolation using pixels bordering the bad pixel regions. The bad pixel regions are input in the specified file consisting of lines of coordinates (x1 x2 y1 y2) where x1 and x2 are the first and last columns of the bad region and y1 and y2 are the first and last lines of the bad region. The file may be STDIN to read from the standard input. The type of interpolation is determined as follows:
If the bad region borders the edge of the image then the interpolation is by replication of the first good pixel in the direction of interpolation and otherwise linear interpolation between the bordering lines or columns is used. The verbose parameter may be used to produce of log of the pixel modifications.
A detector has bad lines 10 and 25 to 27 and a partial bad column at column 31 between lines 35 and 50. A bad region file is created containing the lines
1 100 10 10 1 100 25 27 31 31 35 50
The set of images "image*" are fixed by:
cl> fixpix image* badpixfile
This is a simple minded task which can be improved by using more sophisticated interpolation. The bad pixel file will eventually be replaced by image masks and bad pixel lists in the image. Be careful with image sections because the bad pixel regions are relative to the image section. Also if the image is trimmed or rotated then the bad pixel regions must be changed.