US Patent 8942481 Three dimensional CMOS image processor for feature detection

Disclose embodiments include an image processor for feature detection comprising a single non-planar chip containing a plurality of integrated sensing and processing resources across two or more layers adapted to capture image frames and extract image features. In a particular embodiment, the non-planar chip is a three dimensional CMOS integrated circuit (3D CMOS IC) with vertical distribution of sensing and processing resources across two or more vertical integrated circuit layers. The 3D CMOS IC implements two or more feature detectors in a single chip by reusing a plurality of circuits employed for gradient and keypoint detection. Feature detectors include a scale invariant feature transform detector (SIFT), a Harris-based feature detector, and a Hessian-based feature detector.