METHODS AND APPARATUS FOR TRUE HIGH DYNAMIC RANGE IMAGING

摘要

When imaging bright objects, a conventional detector array can saturate, making it difficult to produce an image with a dynamic range that equals the scene's dynamic range. Conversely, a digital focal plane array (DFPA) with one or more m-bit counters can produce an image whose dynamic range is greater than the native dynamic range. In one example, the DFPA acquires a first image over a relatively brief integration period at a relatively low gain setting. The DFPA then acquires a second image over longer integration period and/or a higher gain setting. During this second integration period, counters may roll over, possibly several times, to capture a residue modulus m of the number of counts (as opposed to the actual number of counts). A processor in or coupled to the DFPA generates a high-dynamic range image based on the first image and the residues modulus m.

主权项

1. A method of generating a digital representation of a scene with a detector element operably coupled to an m-bit counter, the method comprising:
(A) generating, in the m-bit counter, a first count of less than or equal to m, the first count representative of detections by the detector element during a first integration period; (B) generating a residue modulo m of a second count of greater than m, the second count representative of detections by the detector element during a second integration period; and (C) generating the digital representation of the scene based at least in part on the first count and the residue modulo m of the second count, wherein (C) comprises generating the digital representation of the scene with a bit depth of greater than m.