A high dynamic range CMOS image sensor design based on two-frame composition

In this paper, we present a CMOS image sensor design with a high dynamic range. This feature is achieved by a two-frame scheme, in which an image is captured twice with different sensitivity levels. One of them focuses on the low light intensity part of the image, while the other focuses on the high light intensity part. After proper composition, these two frames are then combined as a single image with a higher dynamic range. The proposed scheme is a low-cost solution in the sense that it can be built on top of any traditional sensor design with only minor modification made to the on-chip controller. A simulation environment with post-layout accuracy is used to demonstrate the effectiveness. It shows that a number of pictures, e.g., the one of fireworks, can be captured more clearly than a traditional sensor.