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idedi will dedither a set of INGRID images. It will attempt to detect a peak in the first image given (after pre-processing) and use the RA and DEC keywords from the FITS headers to calculate initial offsets for the remaining images. A 50x50 pixel box is then applied around this initial offset to determine a geometrical center of the stellar images. All images are then shifted by an integral pixel and coadded into the resulting frame, which is divided by the number of contributions on each pixel before being stored.
All images can be pre-processed using the same pre-processing options as available for ipre. idedi will automatically do post-pre if the input file contains two frames, dark image subtraction if a dark image file is specified and flat field normalisation if a flat-field image is given.
Additional pre-processing options include -Z for positivity (set all negative pixels to zero), and -C for cosmic ray/hot pixel removal.
Dark and flat-field images should be prepared with icomb before they are passed to idedi.

The invocation is:
> idedi [preprocessing options] input1.fits input2.fits [... inputN.fits] output.fits

Last Updated: 14 August 2002 Roy Østensen