An analog VLSI focal-plane processing array that performs object-based attentive selection

We have implemented a CMOS focal-plane processing array that performs a selection algorithm based on the intensity profile of the input image. Objects within the image are segmented by normalization, filtering, and thresholding. The selection processing circuits use aggregate information from each object in order to select the most important object within the visual field. All pixel processing is implemented with analog subthreshold circuits. The system includes a multiresolution array of pixels that comprise a 50×48 array of photoreceptors and a 25×24 array of object-based selection processing circuits. On-chip scanners are used to simultaneously display the input and output arrays directly on a multisync monitor. Position-encoding circuitry is also included on the chip in order to output two analog values that indicate the selected position on the array. The system was fabricated in a standard 1.2 μm digital CMOS process. We present experimental results