Abstract
In recent years, advance image processing techniques enables many visual functions such as, robotic vision, motion detection, and target tracking, to be integrated in an imaging system. As spatial resolution of CIS (CMOS Image Sensor) array increases, the image processing loading becomes higher and more complex. In addition, the typical optical response of conventional CIS is linear, which is often insufficient to reflect images perceived by human eyes. In this work, three major subjects are investigated. First, a proposed CDS (Correlated Double Sampling) circuit with variable resolution imaging functions through analog averaging circuits is proposed. This new scheme can effectively reduce data and computational complexity in conventional variation resolution systems. The experiment results show that this scheme introduced averaging error of less than 1 %. Secondly, the proposed CDS can capture the signals of the sensor array operating under different integration lengths, hence and successfully extend the dynamic range. The experiment results show that the pixel can gain different dynamic ranges by varying integration time ratio. Finally, by minor modification the new proposed CDS can operate under both real-time variable resolution and dynamic range boosting modes. The new operation scheme which requires only simple control signals with the modified CDS (Correlated Double Sampling) circuit is successfully demonstrated in a 128×128 CIS pixel array.