Current mode imager with nonuniformity correction and edge detection

We describe a current mode image plane processor for edge detection with adaptive nonuniformity correction. The correction is implemented at the pixel level using floating gate MOS transistors operating in the sub- threshold region. Edge detection is achieved through the convolution of the pixel array with programmable kernel matrices. Under uniform illumination, nonuniformity correction reduces the number of spurious edges detected, thus improving the quality and dynamic range of the image plane processors. A prototype array of 16 × 16 pixels with a pixel size of 44.8 μm by 48.3 μm and a fill factor of 21.25% has been designed in a commercially available 0.5 μm double poly, triple metal CMOS process.