Low power CMOS image sensor with programmable spatial filtering

In this paper, we present a current mode CMOS image sensor with programmable convolution kernels consuming 35 mW of power and operating at 30 frames per second. The image sensor is composed of a 128 by 109 pixel array, digital scanning registers, and a programmable analog processing unit. Convolution of the image is performed on the read-out in the periphery of the image array using digitally programmable low power analog circuits. Difference double sampling (DDS) is performed in the digital domain in order to improve the noise characteristics of the imager. Measurements and preliminary results from the fabricated image sensor are presented.