Research On Imaging Techniques And Processing Methods Based On CMOS Image Sensor

CMOS image sensor is a manufactured image sensor using CMOS(Complementary Metal-oxide-semiconductor)technology. Compared to CCD devices, CMOS image sensor has the advantages of high integration, low power consumption, small size, simple technology, and short development cycle. CMOS image sensors have shown strong developing momentum in the industrial, surveillance, aviation and aerospace and many other fields in recent years. This paper mainly studies the imaging system based on CMOS image sensor hardware and software design and digital image processing algorithm.This paper first describes the theoretical basis for CMOS image sensors technology, introduces the working principle, and performance indicators for CMOS image sensors, and then it further introduces the internal structure, characteristic parameters for the high resolution and large area array CMOS image sensor , and also the structure properties for the CPLD and DSP devices. On this basis, this paper presents the overall design of imaging systems based on CMOS image sensor. The following introduces the idea design and implementation of the program of imaging system. The software design including: CMOS image sensors register configuration, image decoder, address decoder, timing logic control and register control. Thereinto this CMOS image sensor configuration must follow the SCCB bus protocol. On the hardware design, the system use CPLD + DSP platform structure to improve the processing speed, rich control functions to achieve a high-performance imaging system. The hardware system shows that it is stable and reliable on some practical circuit tests.In the image processing part, the imaging system designed in this paper collecting the image is the original RGB Bell array format images, and each pixel has only one color component, so the color jump big of adjacent pixel, especially in the edge area ,such as vague and mosaic phenomenon. To solve these problems, after analyzing the causes of the phenomenon, this paper presents a new adaptive interpolation algorithm. First, as for the image edge detection, the ways is to divide into a smooth area and edge area, to use bilinear interpolation algorithm for the smooth area, also to use the region adaptive interpolation algorithm for the edge area, which is aimed at removal of mosaic phenomena, prominent edge feature. From the experimental results, it can be seen that the visual effect is good. Finally, this paper gives analysis of the experimental result, summarizes the whole work and prospects the future work.