An intelligent readout integrated circuit (iROIC) with on-chip local gradient operations

An intelligent readout integrated circuit (iROIC) capable of pixel-level local gradient operations is presented in this paper. Unlike conventional ROICs whose task is to simply read the pixels and send their raw outputs serially to a computer port, the proposed iROIC performs some essential tasks at pixel-level within the readout circuit, eliminating the need for raw data transmission/conversion/processing externally. The new iROIC uses a bidirectional integrator and a pair of switches to enable gradient operations within a pixel, with minimal overhead. As an enabler example, a real-time texture-based infrared face recognition algorithm is implemented utilizing the proposed iROIC with on-chip local gradient operations. The system successfully achieves a 96.95% correct hit rate over 636 infrared images of 53 individuals.