Wide dynamic camera HD IPC market development direction

Almost all HD network cameras sold on the market have added wide dynamic capabilities. Is this just a coincidence? How to look at this phenomenon?

If the CCD of a high-definition camera is only capable of high definition in a bright and soft environment, and it is "unclear" to a high-contrast environment, it can only be regarded as pseudo-high definition.

Wide dynamic technology is a technique that allows the camera to see the characteristics of the image under very strong contrast, which solves the problem that the dynamic range of the image sensor is narrower than the human eye.

Xia Qichun, deputy general manager of marketing department of Shenzhen Zhongxinxin Technology Co., Ltd., said that if HD cameras can only be used in bright and soft environments, they can only be regarded as pseudo HD if they are “unclear” about high-contrast environments. . Wide dynamic technology is a technique that allows the camera to see the characteristics of the image under very strong contrast, which solves the problem that the dynamic range of the image sensor is narrower than the human eye. When a high-luminance area illuminated by a strong light source (daylight, lamps, or reflection, etc.) and an area with relatively low relative brightness such as shadow and backlight are simultaneously present in the image, a bright area of ​​the image output by the camera will appear white due to overexposure. The dark area becomes black due to underexposure, which seriously affects the image quality. The performance of the camera in the brightest and dark areas in the same scene is limited. This limitation is usually referred to as the "dynamic range." A wide dynamic camera is more than a dozen times larger than a traditional camera with only a 3:1 dynamic range. It allows you to see clearly at dawn, dusk, or cloudy days, and has become one of the performance indicators of a high-definition camera.

It is worth noting that although everyone is still vividly aware of the era of wide dynamics, it is in the era of analog cameras, but it has witnessed the entire process of moving cameras from the analog era to the digital era, especially when the Pixim D2025P program from the United States is widely used. In one fell swoop, it pushed the 256dB level that has not yet fallen behind. Last year's famous Exmor back-illuminated CMOS integrated multi-exposure wide dynamic technology and visibility enhancement (VE) technology, in general, the sensitivity will be reduced after the wide dynamic open, but by opening this function, not only wide dynamic The range of more than 120dB achieves the amazing effect of ultra-wide dynamics, and it doubles the traditional wide dynamic sensitivity by 2 times, and the contrast also increases by 4 times, so that the image effect is greatly enhanced and improved in a low light and bright contrast environment. .

In response, Mao Zhongyu, General Manager of Shenzhen Wave Grain Intelligent Technology Co., Ltd. believes that IPC must be widely used and must be rich in variety, with low illumination, infrared, high-speed ball, backlight compensation, wide dynamics, and so on. To the actual project. If there are few high-definition camera manufacturers, it will greatly hinder the application of high-definition surveillance, so the necessity of wide dynamic high-definition IPC is very great.

The product director of Hangzhou Hikvision Digital Technology Co., Ltd. should solve the problem of image details to Qun-HD, greatly enhance the customer's experience on the image sensory, and also solve the customer's original "visible, invisible" reality. problem. However, for the actual, natural light environment, there will be bright and dark at the same time, and this time will inevitably require a wide dynamic function. As a result, Hikvision has increased its R&D investment with wide dynamic capabilities, such as the launch of 1.2 million and 2 million high-definition wide dynamic cameras to solve customers' practical needs.

Hou Wudong, deputy general manager of Mika (China) Co., Ltd. also holds the same view, he said in the interview, the implantation of wide dynamic function in the IPC is an inevitable trend, simply speaking, wide dynamics are particularly bright parts of the scene and special Dark areas can be seen particularly clearly at the same time. The wide dynamic range is the ratio of the brightest luminance signal value to the most recognizable dark luminance signal value of the image.

Due to the fact that the actual monitoring environment is often unsatisfactory or very complex, the image obtained by using a traditional CCD is often not ideal. Due to the limitations of the CCD's photosensitivity, it is technically difficult to achieve major breakthroughs, and the CMOS technology has reached 160dB. With CMOS technology cameras, the wide dynamic range is greatly improved over the wide dynamic range of the CCD. For DPS technology, each pixel corresponding to the light can optimize the exposure, each frame of data read time is only 0.8 milliseconds (the traditional CCD technology requires tens of milliseconds), so that the system can sample each pixel multiple times; The imaging system controls the optimal sampling time for each pixel and stores pixel information when each pixel reaches its optimum state. After all pixels are captured, the system processes them again, resulting in a high-quality image. Even in the harshest lighting conditions, clear, realistic images can be captured, and images will never be darkened or destroyed due to shadows, glare, reflections, and sunlight. Therefore, it can be said that the future surveillance cameras belong to wide dynamic cameras and the wide dynamic technology belongs to CMOS.