Stack Analysis (ppStack)

Stack Masks

Updates added 2010.10.29 : Previously, we were only setting bad mask bits, and only setting a single vale (BLANK) for all bits. As of ipp-20101029, the code now does the following:

• for bad pixels, set the output mask to the OR of all bad input pixels
• for good pixels (ie, a value is calculated), set the output mask to the fuzzy AND of the inputs pixels actually used to calculate the output pixel value. The fuzzy AND raises a bit if 65% of the input pixels see that bit. This change was necessary to allow the nightly stacks to include information about suspect pixels due to, eg, excessive burntool or excessive diffraction spikes. The suspect nature of the pixel folds into the PSF_QF_PERFECT score (psf-weighted fraction of pixels with neither BAD nor SUSPECT pixels).