The Research Of HDR Image Acquisition Technology Based On CMOS Image Sensor

Since the CMOS image sensor emerges in1969and the CCD image sensor emerges in1970, the image sensor has developed rapidly and got widely used. CCD image sensor tookthe leading position of the image sensor market with such advantages as the low noise, lowdark current, high image quality and dynamic range. In1989, CMOS image sensor becamethe focus of research with the emerging of the active CMOS image sensor. The active CMOSimage sensor has many advantages, such as high integration, low power consumption, highability of anti-radiation. Of course, it has some shortcomings including big noise and lowdynamic range. So, there are the two central aspects in the research of CMOS image sensor:heighten its Signal-to-Noise ratio and dynamic range. In recent years, CMOS image sensorbegan to be used in the field of military and space exploration. In this paper, we choose theCMOS image sensor MT9M034, which was produced by Aptina Corp, as the core device ofthe imaging system to have a research on the engineer implement method of High DynamicRange technology in imaging system that based on CMOS imaging devices， which now hasgreat significance and practical value.This paper has done some research from the following aspects:1. Study the development of CMOS image sensors and CCD image sensors, theiradvantages and disadvantages as well as the structure of CMOS image sensor, its workingprinciple and main performance indicators. Also study the status quo of CMOS image sensorexpansion technology at home and abroad.2. Proposed a joint method based on wavelet transform and curvelet transform for imagedenoising.3. Choose the MT9M034CMOS image sensors of Aptina Corp to build a high-definitionCMOS imaging system to complete the HDR camera technique on the hardware platform.4. Make use of the Vitex-5FPGA to accomplish the control and the data processing ofthe whole system in order to achieve the following functions: The timing control of MT9M034, the configuration of the CMOS registers via I2Csignal bus to realize the initialization of the whole system;The image data companding transformation,color recovery and color spaceconversion.The read-and-write control of SDRAM memorizer.The synthesis of high-definition serial digital video data.The SDI channel coding and SDI interface control.Experiments show that this high-definition imaging system works stably, which canwork very well in the linear model and the HDR mode with a good imaging performance. Inthe end, this essay makes a summary about the whole system and point out the disadvantagesof the system as well as put forward some methods to improve. What s more, this system isalso helpful for other products and design of systems of the same sort to take for reference.