Ability to stretch a selected portion of an image.
Examination of multi-amplifier CCD images before calibration (e.g., on hardware test stands.
When new CCDs arrive from the vendor for testing, the various amplifiers (each LSST CCD has 16) do not have gain or baseline calibration. The result is that the image will resemble a checkerboard, with some amplifier regions being very dark, and some very light. Visual examination of an amplifier for blemishes would be easier if its stretch could be adjusted without regard to what is happening with the other amplifiers.