What is the camera movement? Analysis of the integrated camera movement

Integrated cameras generally refer to cameras with built-in lenses and can automatically focus. They share a core component with spherical cameras (dome cameras), the integrated camera movement (referred to as the all-in-one movement). The editor below will introduce to you the knowledge of the integrated camera movement.

The all-in-one machine movement is mainly composed of two parts: the optical part and the software and hardware (autofocus board, etc.). The optical part is the imaging system of the all-in-one machine core, usually called an all-in-one machine lens. The all-in-one camera lens is the core component of the all-in-one machine movement, which directly affects the quality of the all-in-one machine movement. The R&D and manufacturing manufacturers of integrated camera movements basically adopt the method of outsourcing all-in-one lenses. The criteria for judging the quality of all-in-one lens can be roughly divided into: optical performance, stability and consistency of key components. Optical performance mainly refers to the resolution of the lens at various optical magnifications; other factors include the severity of ghosting, purple fringing, dispersion and other problems. Key components mainly include: aperture, motor, filter switching and other components. According to the quality of all-in-one lenses, they can be roughly divided into three categories: Japanese lenses, Taiwanese lenses and domestic lenses. Japanese lenses generally have good optical performance and stability, but their prices are high; Taiwanese lenses are relatively cost-effective, but their optical performance, especially high-magnification resolution, is insufficient; and all-in-one lenses from domestic manufacturers are less than ideal in terms of stability and consistency.

In addition, filters are also part of the optical system, but are sometimes not taken seriously by camera R&D companies. High-quality filters have a unique effect on image color and reducing optical deficiencies of the lens. Related to the optical system is the photosensitive device. Since the monitoring environment used in all-in-one machine core applications usually requires round-the-clock monitoring, it has the same requirements during the day and at night. To take into account both daytime and nighttime effects, CCDs are currently generally used. Since the optical aperture of standard-definition lenses is only 1/4 inch, standard-definition all-in-one machine movements generally use 1/4-inch SONY CCDs (especially for their superior low-noise performance). For high-definition all-in-one machine movements, the photosensitive device needs to be selected according to the lens aperture. All along, CMOS imaging devices have been inferior to CCDs in terms of speed and low noise, while CMOS has been greatly improved in terms of low noise. From a comprehensive cost-performance perspective, CMOS is also relatively better than CCD in terms of back-end DSP processing and heating; therefore, CMOS sensors will be used more and more in high-definition all-in-one machine movements (especially digital high-definition all-in-one machine movements). In addition to the optical system, the software and hardware system is the main development part of the integrated movement development company, and its core technology lies in automatic focus.

Compared with ordinary cameras, the main difference of all-in-one camera movements is Auto Focus, which is also a bottleneck that limits the development of domestic all-in-one camera movements. The quality of focusing speed and effect directly affects the user's capture and recording of images at the surveillance site. A good product can focus accurately in one go; on the contrary, it will go back and forth when focusing, and it takes 3 or 4 times to get the focus, and even worse, it cannot focus on the "clear point".

The technology of automatic focusing has become a technical problem that manufacturers urgently need to solve. At present, there are two ways to implement automatic focusing: active and passive. Among them, active automatic focusing is relatively simple and low-cost, but the control is not as flexible as passive automatic focusing, and the focus and effect are poor; while passive automatic focusing generally collects video signals and calculates energy edge operators or

Extracting high-frequency components, the control is very flexible and the algorithm is advantageous. The focus is good, including focusing on high-contrast scenes and low-illumination scenes.

The performance of autofocus can be evaluated from three aspects: focusing degree, focusing speed, and stability when focusing. Focusing degree mainly reflects the focusing accuracy under various environments and various optical magnifications. Various environments mainly depend on the focusing accuracy of various illumination, especially at night. In scenes with lights and scenes with illumination below 1 Lux, the focusing accuracy of different focusing algorithms varies greatly, which is a major difficulty for focusing algorithms.

Focusing speed mainly reflects the speed of focusing after switching various scenes under various optical magnifications. Since the focal length is long at large magnifications, a simple test method is to switch to the time it takes for a distant object (such as an object 50 meters away) to focus after a close object (such as an object 3 meters away) is focused at a large optical magnification of the lens. A good AF algorithm can quickly focus once, while a poor AF algorithm will cause the image to swing back and forth, giving the user the impression that it is focusing multiple times, and the focusing speed is slow. The stability of fixed focus is not valued by users because it is difficult to test; when the optical magnification is large, the AF algorithm with poor performance will often focus back and forth when monitoring scenes with large moving objects. Especially at night, sometimes it is found that the monitored scene is blurred and unstable for a long time.

What is a camera movement? The above is the knowledge about the integrated camera movement. The core technology of the integrated camera movement, the design of the integrated lens and the autofocus algorithm are already quite mature.