mask_head -- attach mask names to image headers; invert mask if requested
mask_head images masks
This task prepares images and masks for the use of imcombine, primarily by placing the name of the associated pixel mask in the header of an image under the keyword "BPM". The original input mask is copied to a mask of the same name, but saved pixel list (.pl) format. If "invert" is set to "yes", then any value greater than 0 is set to 0 and all other values are set to 1. If "invert" is "no", then all values greater than 0 are set to 1, and all others are set to 0.
For an example of the use of this task in reducing dithered WFPC2 observations, see the paper by Fruchter and Mutchler at
This task will fail if the original mask is already in pixel list format (i.e. has the image suffix ".pl").