SIRTF IRAC Test Data, Calibrated Image, Revisit

HST WFPC2 PC1 data of R136 was used; image is 800 x 800 pixels
  (files d2hk0318t1.fits (image) & q2hk0318t1.fits (mask))
The WFPC2 data is of the same field and exposure time as the calibrated image
for Visit 1, but has been shifted (delx=10, dely=-5) and rotated
(by 5 degrees) to mimic an IRAC revisit of one of our fields.

- want 2 adjacent fields of view for the channel 1 & 3 data & the channel 2 & 4 data
  for both the image and the mask files, take a section from the upper right hand 
  corner of the WFPC2 image
  if channels 1 or 3,
    take a 256 x 256 section whose lower left corner is x=335, y=310
  if channels 2 or 4
    take a 256 x 256 section whose lower left corner is x=315, y=165
  rotate the calibrated image by 5 degrees about the pivot point x=347, y=333

modify calibrated image by adding bad pixels 
 o Use bad pixel info from the WFPC2 mask file that came with the image file.
  - In that file, the questionable pixels flagged as "258" were made worse in this 
    image by multiplying them by 0.6. (This represents "responsivity unstable".)
  - Take another set of bad pixels from the WFPC2 mask file, flagged as "2", and 
    modify those pixels of the calibrated image by multiplying them by 1.4 
    ("responsivity too high").
 o Dead pixels
   Choose 0.1% of the pixels randomly (set them to "8" in the bad pixel map) & 
   modify those pixels in the calibrated image by setting them to "-1".
			 
add noise to channel 3 & 4 images (to see if we can find it in our Level B 
processes)
  for all pixels in the image, take a random number between -1 and 1 and multiply it
  by 2, then add it to the value of the pixel in the image (only for channel 3 
  & 4 data)