SIRTF IRAC Test Data, Quality Image Data

Data quality mask
  0 = OK
  1 = saturated pixel
  2 = pixels affected by banding (correction will be applied in SSC pipeline)

- Use saturated pixel info from the WFPC2 mask file that came with the image file.
  In that file, the saturated pixels were flagged as "8".  Change flag to "1" in
  our file.

- Banding - only in quality mask for channel 3
  Banding from bright sources affects only channels 3 & 4.  For a banding affected 
  region, we selected a star in the lower left hand part of the channel 3 image and
  created a "X" pattern in this image which overlayed an area on the star. 
  The value is set to "2". This isn't quite right since banding effects are 
  horizontal and vertical (rows & columns) but we really only care about checking 
  for the flag at this point.