Human object detection is an important research direction in the field of computer vision. The research content includes human target segmentation, recognition, tracking, behavior analysis, etc., which belongs to the category of image analysis and understanding as a whole, and specifically involves image processing, pattern recognition, computer vision, artificial intelligence and other disciplines.

 

General composition of human object detection system

 

The human target detection system is mainly composed of image acquisition equipment, image processing hardware, and image analysis software.

1) Image acquisition equipment

Image acquisition equipment mainly includes infrared thermal imager, visible light camera, depth camera, near-infrared camera and other types. Among them, the infrared thermal imager relies on the object to be measured and the temperature difference between it and the background to image, is not disturbed by light and shadows, has good penetration performance, and can work effectively in environments with low visibility, but the obtained thermal infrared images have The spatial and temporal resolution is low, and the edges are blurred, which cannot preserve the detailed information such as the geometry and texture of the object, and is easily affected by temperature. In contrast, visible light cameras have higher spatial and temporal resolution, and the resulting images contain rich color, geometric and texture details, but are sensitive to light intensity and are easily affected by factors such as occlusion and shadows. Depth cameras can provide scene depth information, and there are many types, one of which is the TOF camera. The TOF camera obtains the target distance through the propagation time of light. The calculation accuracy is not sensitive to the distance change, but it also has limitations. For example, it needs an active light source during operation, and the obtained image has a low resolution. Strong ambient light will affect its performance stability. Wait. The near-infrared camera can actively project infrared light onto the object in the absence of visible light or low light environment. The infrared light is reflected by the object and then enters the lens to achieve night vision imaging, but the night vision effect is often not ideal.

 

2) Image processing hardware

Image processing hardware includes high-performance single-chip microcomputers, namely multipoint control unit MCU, digital signal processor (DSP), field programmable gate array (FPGA) device industrial personal computer (IPC). And personal computer (personalcomputer, PC) and other types. Among them, MCU has the characteristics of low power consumption, rich peripherals, strong versatility, and many categories. DSP focuses on strengthening computing performance in structure. For example, the TIC5000/C6000 series is very suitable for large computing scenarios such as video image processing. FPGA is a "sharp tool" for function customization and parallel fast processing. Due to the use of full hardware to process signals, the speed is the fastest, but the development difficulty is relatively higher. These three are often used to build compact, low-power portable embedded systems. Compared with embedded systems, IPC and PC have the advantages of stronger performance and better versatility, but they are not dominant in size and power consumption, and are mainly used to build non-portable desktop systems. IPCs are usually specially designed for reinforcement, dust-proof, moisture-proof, corrosion-proof, radiation-proof, etc., and are generally used in industrial environments with high requirements for data security and harsh environments. PCs are mainly used for civilian use and do not have high requirements on the physical environment. They are mainly used in home and office environments. Combining different types of image acquisition equipment and image processing hardware can build unique human target detection systems.

 

3) Image analysis software

The image analysis software runs on the image processing hardware and is the "soul" of the human body target detection system.

 

The human target detection system based on visible light images is the earliest developed, the most widely used, and the most mature technology. However, because the visible light imaging equipment cannot adapt to the bad weather environment such as night and rain, fog, and snow, the application scope is greatly limited. In comparison, the human object detection system based on thermal infrared images has obvious advantages, because the brightness of the human body in infrared imaging is higher than that of the background, and it is hardly affected by skin color, surface texture and shadow, especially in long wavelengths. In the infrared band (8~14μm), passive imaging mode is used, which does not require the intervention of auxiliary light sources, which makes up for the deficiency that visible light images are easily limited by ambient lighting conditions. In addition, the surface temperature is about 300K, and its infrared radiation is located in the long-wave infrared band, which is the main area for surface target imaging. In recent years, combined with the technological progress of infrared thermal imaging equipment and the favorable factors of price reduction, the human target detection system based on thermal infrared images is in the ascendant. The related theoretical research and technology development are developing rapidly, and the application field is expanding.

 

Shenzhen Shiyutong Technology Co., Ltd. is a high-tech enterprise focusing on the development, production, sales and service of night vision devices and monitoring systems for many years.

 

Based on product cost performance and user experience, the company has many technical advantages in image enhancement. Professional research and development team, leading technology and technology, customized to create international high-quality night vision device brand.

 

Its products are widely used in nature observation, outdoor hunting,outdoor exploration, security and anti-theft, sea operation, night patrol and other occasions.