Design Of CMOS Image Sensor Automatic White Balance Digital Process Circuit

Compared with CCD, CMOS graphic sensor integrates the real time disposing circuit and the front part amplification of graphic signal into one chip. Its development is widely noticed in digital region. It is widely used in video monitor and multimedia region because of its low price, good graphic quality, high integration and low power consumption.In this paper, the design and implement of CMOS graphic sensor digital pre-disposing circuit's AWB module are achieved. Because it is the design of single chip system, it is required that the circuit is small in scale, low resource consuming, low power consuming and easy to transplant.The algorithm of the design is based on the MATLAB simulation of the algorithm which is already advanced by other people. Considered the complexity of implement and the effect of disposition, it developed a kind of method combined gray world and ideal reflector to modify color. Combining the two algorithms to expand the scope in point, it makes up the shortage of the two algorithms. With this algorithm, we can complete the calculation of AWB's plus without saving the picture. In order to save the resource and meet the need of real time, the design marks out the region of statistics and calculation and controls a division device to do the consecutive divisional calculation by a state switch set. The design uses a pipeline multiplication set in data disposing part in order to expand the appropriate scope in frequency and enhance the transplantation of the design. For reducing the power, alternative frame startup AWB is used in the design. Sub-modules are designed in Verilog HDL in the design and the source of stimulation is built to do the verification of the design by combining MATLAB and Verilog HDL. The design has better effect of emendation for graphic color inclining in different color temperature environment.