Study On High Definition Capturing System Base On TMS320DM6446

This paper is research on the the 5 million pixels Charge Couple Device (CCD) drive circuit, and the design of a traditional way of analog image acquisition of different high-definition digital image acquisition system.It can be used in many situation such as the distance of active object changes,image processing when the resolution of image is high,the purpose of this is implementing the function that the equipment can acquire clearly,extract and recognise the active object.Due to the key part of the High Definition Capturing System is the lens,CCD and the platform of processor.Firstly,this paper presents the action principle of CCD,pixel structure and niose mode of the CCD,the 5 million pixels CCD type of the this system is RJ23S3CA0ET, this paper gives a detailed description on the internal drive principle of driver chip LR38667 and external circuit,then,it introduces the optic design principles of zoom lens simplely.Because the zoom lens is a instrument which integrated optic,electric and mechanic,its drive is relatively complex, this paper emerged the optic route of the zoom lens,then it gives a description on the drivers of micro DC motor controls foci of the lens and the micro step motor controls focus operation.This processor platform of High Definition Capturing System is Davinci made in the Texas Instrument,it makes the function of this entire High Definition capturing system become strong. The paper is mainly a research on the construction of Daivinci's hardware,it refers to the design of DDRII memory running up to the speed of 135Mhz. Because of its abundance peripheral, we just emphasis on the research of display module VPBE(Video Processing Back End) driving the TFT screen with 320×240 resolution,CCD controller module capturing high resolution image, preview engine module with a series of hardware accelerated function of white balance,gamma correction,color space transform,black level compensation and low pass filter etc, auto focusing module in the H3A(auto focus,auto exposure and auto white balance), and the SD card controller in the aspect of data storage. Because of its abundance function, this paper just presents media stream framework and memory model of the High Definition capturing system on the Linux platform from the general design of framework work,it also do some research on the device drivers in the bottom of the configuration,places some basic matting for the future work.On this platform,we also do some research on the definition evaluate function, put forward a kind of definition evaluate function combined energy grads operator based on the image data in the raw format,it can use in the auto-focusing as a object function.General speaking, comparing to traditional analog video capturing system,it has the advantage that of high pixels,low-cost,has a good practical value.