Enhancing sensitivity for Active Pixel Sensors with fault tolerance and demosaicing

A key advantage to the Active Pixel Sensor (APS) over the traditional charge coupled device (CCD) is the ability to integrate electronics on chip. As image sensors become larger the number of defective pixels increases. In this thesis, a fault tolerant APS design is investigated that functions even in the presence of defects typical for image sensors, focusing on its sensitivity and a noise analysis with defects. The design has nearly twice the sensitivity and the signal-to-noise ratio only decreases slightly under typical illumination, without faults. Based on this increased sensitivity, modifications of the standard pixel are investigated for sensitivity improvements. The Bayer colour filter array (CFA) is commonly used in digital cameras. Demosaicing, using a modified Bayer CFA is presented where one of the green locations is substituted by a panchromatic pixel. The panchromatic pixel enables for better low light capture and directly provides luminance information.