DSP-based Depth Form Defocus System Implementation

With the technology of micro-electronic developing promptly in recent years, the process ability and speed of electronic appliance and equipment has increased greatly, which provides the hardware platform for the mass data processing and the complex system control. So, the processing technology of digital image also has made great progress, and has applied in the fields such as digital camera, video detection and image measurement.In the study of image measurement, the three-dimensional (3D) reconstruction of the objects is mostly based on focused image making use of the technique of infrared ray, laser etc. Although the measuring accuracy of these methods is very high, it also makes some disadvantages that the system is too complicated, carrying out difficulty and the cost high etc. Reconstruction the 3D information of objects by virtue of depth information and estimation the distance from objects to the camera is based on depth from defocus (DFD) in this paper. In addition, it utilizes the latest technical appliances. The main features of this system lie in its small volume, high integration degree and real-time. It mainly applies to the situation in which asks for high real time and not too much accuracy. And it has much actual application value in many fields.The system consists of three parts: image acquirement, control of step motor drive and DFD. The CMOS image sensor has some advantages of simple structure, high degree of integration, low power consumption and easy integration with other chip, and it also can obtain digital image directly. With the technique of making CMOS image sensor being improved, CMOS image sensor is taking more and more quotients in the market it seems to have a trend to replace the traditional CCE image sensor, the algorithm processor chip adopts company TI's floating-point DSP of series C3x. It's the core of this system and is not only in charge of the DFD operation, but also the screening of image sensor and control of step motor. It operates the whole system by shaking hands with CPLD. This paper adopts the technique of digital image processing— such as image filter, edge processing etc, and depth estimation from defocus based on moment-preserving and gets favorable effect.