1. An imaging system, comprising: a primary integrated image sensor comprising: a first pixel array for capturing images; a first timing circuit for generating timing signals, wherein the timing signals include signals used to read out the captured images from the first pixel array; an image signal processing circuit for processing captured images; and a bi-directional digital input/output circuit for outputting the processed images; and a secondary image sensor operatively connected to the primary integrated image sensor, the secondary image sensor comprising: a second pixel array for capturing images; a second timing circuit for generating timing signals, wherein the timing signals include signals used to read out the captured images from the second pixel array; and an output circuit, wherein images captured by the second pixel array are provided as an input to the image signal processing circuit on the primary integrated image sensor.