Extending the dynamic range of linear CMOS sensors

Extending the dynamic range of digital imagers is a rather recent applied science, where some research has already been done since Europe launched the joint research program EUREKA in 1986. However, the limitations of the image sensors and the processing power of the embedded processing systems used (e.g. in digital cameras), in addition to higher cost factors, prevented these systems being fast and therefore applicable. Since there is a growing demand for driving assistance systems and observation systems, special care and research is required to immunize vision systems against changing physical daylight conditions. This paper discusses a grayscale image sensor hardware framework and a recently developed implementation for the proposed solution to extend the dynamic range of a linear complementary metal-oxide-semiconductor (CMOS) sensor. A suggestion is made for a very large scale integration (VLSI) hardware system, which is firstly simulated in ModelSIM. In respect of generic attributes, the interfaces to image sensors and storage locations are highly adaptable in this approach.