Cmos Image Sensors with Multi-bucket Pixels for Computational Photography a Dissertation Submitted to the Department of Electrical Engineering and the Committee on Graduate Studies of Stanford University in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy

When applied to multi-image computational photography such as flash/no-flash imaging, multiple exposure high dynamic range imaging, multi-flash imaging for depth edge detection, color imaging using active illumination, and flash matting, an image sensor that can capture multiple time-interleaved images would provide a dramatic advantage over capturing and combining a burst of images having different camera settings. In particular, this interleaving eliminates the need to align the frames after capture. Moreover, all frames have the same handshake or object motion blur, and moving objects are in the same position in all frames. A sensor with multi-bucket analog memories in each pixel can accomplish this task. Whereas frames are acquired sequentially in a conventional sensor, in a multi-bucket sensor photo-generated charges in a photodiode can be transferred and accumulated in the in-pixel memories in any chosen time sequence during an exposure so multiple frames can be acquired virtually simultaneously. Designing a multi-bucket pixel which is compact and scalable is challenging because space is required to accommodate the additional in-pixel memories and their