SIRTF IRAC Test Data, Latent Image Mask

Latent image mask
   0 = pixel OK
   1 = latent image - medium expected detectability (<75% probability) 
       (may still be able to use data)
   2 = latent image - large expected detectability (>75% probability)
       (cannot use data) 

To create the latent image mask file, we took the latent image file and normalized 
it to the maximum value for that file.  Then for values greater than 0.95, we set 
the mask to "1" (medium expectation of latent image) and for values greater than 
0.985, set the mask to "2" (high expectation of latent image).