What Is Video Image Processing?

A video image is a sequence of continuous static images, which is a more vivid and vivid description of objective things. A video image processing system is a system that processes a video image based on an image processing algorithm.

The development of image processing depends on the application and development of computers. It is a very active part in the field of computer applications, so sometimes image processing and computer image processing are equivalent. The development of image processing systems is extremely rapid, mainly due to the ultra-high-speed development of computers. In addition, the rapid development of semiconductor devices has also accelerated the development of image processing systems. At the same time, more and more people are engaged in image processing research work, and the development of theoretical research has in turn promoted the development of image processing systems. So far, the development momentum of image processing systems is still very strong.

Image processing systems are divided into two categories: general image processing systems and special image processing systems. General image processing systems are based on computers, such as microcomputers, minicomputers, workstations, mainframes, etc .; special image processing systems are systems used by end users. They are generated and developed with embedded applications. Based on hardware such as ASIC (Application Specific Integrated Circuit), DSP (Digital Signal Processing), and FPGA, this system does not require secondary development. At present, with the continuous development of multimedia technology and semiconductor technology, the use of embedded image processing systems has gradually become the mainstream. The embedded image processing system is mainly a hardware solution using a dedicated processing chip, a digital signal processor DSP or a field programmable logic gate array FPGA.

At present, the development speed of programmable logic devices is particularly fast. The capacity of FPGA has exceeded one million gate levels, and SOPC can be realized on FPGA. FPGA mainly has the following advantages: repeatable, programming system-level upgrade is convenient and easy to implement; speed and capacity are steadily increased, and the software and hardware inside the system can be flexibly configured according to needs. In addition, many manufacturers also provide many common IP cores to make design It is quite modular and can design complex systems in a short time. Software and hardware design can be carried out under the same platform, which can conveniently implement system functions. For various reasons above, the field programmable gate array FPGA has become one of the important first choice solutions for image processing systems. ^[1]

Traditional video image processing technology mainly uses a PC for real-time image processing. Because the structure of the PC is based on Von Neumann's complex instruction computer, which essentially executes instructions sequentially and cannot achieve parallel processing, the real-time performance is poor; Use DSP special chip for real-time image processing. Because it uses the Harvard structure that separates data from program space, it can achieve certain parallel processing and complex algorithms, but it cannot achieve some more complex logical operations and high-speed processing. With the continuous advancement of technology, FPGAs are not only cheap, but also have significantly improved performance. At the same time, hardware resources are highly integrated, programmable logic unit capacity is large, speed is faster than PC and DSP chips, development cycle is greatly shortened, and SOPC ( Programmable System on a Chip) is increasingly being used in video image processing technology. ^[2]

A typical video processing system uses a microprocessor to control a video pipeline. The video pipeline includes a video source and sink, a large memory for storing video data, and a video algorithm function to implement some algorithm processing functions. as the picture shows. ^[3]

Video image processing systems can be divided into PC-based video image processing systems and DSP or FPGA-based image processing systems based on their types and comprehensive characteristics.

(1) Aerospace. Mainly used in space imaging, aircraft remote sensing and satellite remote sensing technology. Whether these images are in the process of imaging, storage, transmission, or interpretation analysis, image processing methods must be used. Countries around the world are using images acquired by satellites for resource surveys, disaster detection, resource surveys, agricultural planning and urban planning. Image processing technology has also played a significant role in weather forecasting and research on other planets in space.

(2) Biomedical engineering. It is mainly used for CT technology and processing and analysis of medical microscopic images, such as red blood cell, white blood cell classification, chromosome analysis, cancer cell identification, etc. In addition, it has a wide range of applications in medical diagnosis such as X-ray lung image sharpening, ultrasound image processing, electrocardiogram analysis, and stereotactic radiation therapy.

(3) Communication engineering. It is mainly used for multimedia communication combining sound, text, image, and data. Specifically, the telephone, television, and computer are transmitted on a digital communication network in a three-in-one manner. Among them, image communication is the most complicated and difficult. Because the amount of data transmitted by the image is huge, to transmit the data in real time at a high rate, it is necessary to use the encoding technology in image processing technology to compress the bit amount of information.

(4) Industrial engineering. It is mainly used for testing the quality of parts in automatic assembly lines, classifying parts, inspecting printed circuit board defects, stress analysis of elastic mechanics photos, resistance and lift analysis of hydrodynamic pictures, automatic sorting of postal letters, etc. Identify the shape and arrangement of workpieces and objects in toxic and radioactive environments, industrial vision, etc. There is also the development of intelligent robots.

(5) Military police. Mainly used for accurate guidance of missiles, interpretation of various reconnaissance photos, military automatic command system with image transmission, storage and display, aircraft, tank and warship simulation training system, etc .; interpretation and analysis of public security business pictures, fingerprint recognition, human face Identification, restoration of incomplete pictures, traffic monitoring, accident analysis, etc. The automatic recognition of vehicles and license plates in highway toll collection systems that are currently in operation are examples of successful application of image processing technology.