Abstract: In one aspect, a method provides for iteratively taking passes of samples for each pixel of a set of pixels. Initially, the set of pixels can be all of the pixels of an image. For each pixel, an accumulated color at the beginning of a pass and at the end of a pass can be compared. If a difference between these is within a threshold, a convergence count, which begins at an initial value, is reduced. If the difference is not within the threshold, then the convergence count is reset. When the convergence count reaches a preset value, then the pixel is considered converged and removed from the set. However, if a pixel adjacent to a converged pixel fails a convergence test, then the converged pixel is reset to unconverged and returned to the set and at least a minimum number of additional sample passes are undertaken for that pixel.

Abstract: A calibration system and method for calibrating a detector are disclosed. In one example, the calibration system comprises a plurality of radiation sources configured to emit electromagnetic radiation, a positioning mechanism disposed opposite the plurality of radiation sources, having a single degree of freedom with respect to the plurality of radiation sources, and an optical element coupled to the positioning mechanism, and configured to rotate to a plurality of calibration positions, the optical element in each of the plurality of calibration positions being configured to receive the electromagnetic radiation from a corresponding radiation source and to reflect the electromagnetic radiation to the detector.