Runs mDiff on all the pairs identified by mOverlaps.
mDiffExec [-p projdir] [-d] [-n(o-areas)] [-s statusfile] diffs.tbl template.hdr diffdir


-p projdir
Specifies path to the directory containing reprojected input images.
Turns on debugging.
No-area-images flag. Creates difference image without requiring _area FITS images
-s statusfile
Output and errors are sent to statusfile instead of to stdout


Table generated by mOverlaps for the images in projdir.
FITS header template for output files.
Path to output files.
FITS images representing the differences for each pair of overlapping images. nimages is the total number of images succesfully processed, and nfailed is the number of images that failed. The most likely cause of failure is that the FITS images overlapped, but only in areas where they contained blank pixels (especially common in images with large degree of rotation).


First, diffs.tbl is generated using mOverlaps. Then mDiff can be run on reprojected images, using this template.hdr.

$ mDiffExec -n -p projdir projdir/diffs.tbl template.hdr diffdir
[struct stat="OK", count=42, failed=0]

Return Codes:

  • [struct stat="OK", count=nimages, failed=nfailed]
  • [struct stat="ERROR", msg="Usage: mDiffExec [-p projdir] [-d] [-n(o-areas)] [-s statusfile] diffs.tbl template.hdr diffdir"]
  • [struct stat="ERROR", msg="MPI initialization failed"]
  • [struct stat="ERROR", msg="Cannot open status file: statusfile"]
  • [struct stat="ERROR", msg="Cannot access diffdir"]
  • [struct stat="ERROR", msg="diffdir is not a directory"]
  • [struct stat="ERROR", msg="Invalid image metadata file: filename"]
  • [struct stat="ERROR", msg="Need columns: cntr1 cntr2 plus minus diff"] (columns missing from differences table)
  • [struct stat="ERROR", msg="mDiff error"]