CCD Noise Rejection Circuit Design And Algorithms Research Based On DSP

With the continuous development of the CCD (Charge Coupled Device) technology, itsapplication is more and more extensive. The noise of the CCD output image has become anobstacle to the further development of CCD. Especially in the low luminance condition thenoise is more obvious. Poor contrast and low signal-to-noise ratio seriously affects the imagequality, so the study of CCD low illumination image noise becomes necessary. How to ensurethat the image noise reduction and maximize the retention of the edge details of the image atthe same time is a difficult problem at present.This topic analyses the noise source of the CCD and the traditional denoising methodsfirstly, considering both of hardware and software. Then, we build a CCD video camerasystem, design the denoising circuit and denoising algorithm. Finally, we verify theeffectiveness of the algorithm using PSNR image evaluation.The main work of this paper includes the following aspects:(1) Analyzes the working principle of CCD and the noise source of CCD.(2) Describes the hardware circuit design of the CCD camera system used in this paper,set up the hardware platform. The platform includes the follow modules: the CCD module,DSP module, embedded (ARM11) module, image acquisition module and the computerMATLAB simulation module.(3) Designed the noise reduction circuit of the CCD output module and use the correlateddouble sampling method to remove the reset noise.(4) Implemented the denoising algorithm with the MATLAB, including airspace,frequency-domain denoising algorithm and a hybrid filtering algorithm.(5) Evaluates the noise reduction algorithm using PSNR. comparing with the traditionalnoise reduction algorithms,the proposed hybrid filtering algorithm shows that the noisereduction effect is more significant.