Abstract: Variations of the techniques, systems, devices, and methods discussed herein pertain to a pixel-level mask for a photo-detector. Such a mask may have a layer of reconfigurable phase-change material (PCM) configured to vary between a first refractive index and a second refractive index. Such a PCM layer may be divided into individual pixel areas such that each individual pixel area may be set to have the first refractive index or the second refractive index. The PCM layer may be disposed on a photo-detector such that incident radiation detected by the photo-detector must pass through the PCM layer in order to be detected. The mask may also include or otherwise be operably connected to a PCM controller that can control the refractive index of an individual pixel area or a group of pixel areas aggregated into a superpixel.