We have tried to observe and analyze from a broader perspective to provide users with a comparison of the differences between the two types of cameras, such as performance, open systems, flexibility, future expansion guarantees, and network connectivity. In this article, we attempt to identify the 10 most important functional differences between today's network cameras and their outdated analog counterparts, making it crucial for you to understand these factors the next time you consider purchasing a camera.
1Analog cameras face significant interlace issues at resolutions up to 4CIF, as all video is made up of lines, and each image consists of two interlaced line fields. When there are many moving objects in the image, it can become blurry or have jagged edges because objects are captured between the two interlaced fields. Network cameras do not have this interlace problem, as they use progressive scan technology, which is ideal for capturing clear images of moving objects. This advanced image capture technology allows the entire image to be captured at the same time, providing sharp, discernible images even when objects are in rapid motion.
2Powering analog cameras is always a major obstacle and cost. The IEEE 802.3af standard Power over Ethernet (PoE) confirms that significant cost savings are possible; this was not designed for analog cameras. PoE refers to supplying power over the same Cat.5 network cable that transmits data and video from a PoE-enabled switch or hub. Because this standard has been established, all equipment is compatible and maximizes user benefits. In security applications, PoE offers another advantage: cameras can receive centralized backup power from the computer room, ensuring uninterrupted operation even during local power outages.
3Analog cameras are limited by NTSC/PAL standards, with a maximum resolution of 400,000 pixels at 4CIF. Users are demanding higher megapixel resolutions for the latest high-definition computers and digital cameras, and the same demand exists in the surveillance market. Higher resolution from network cameras provides finer quality and can cover a wider area, ensuring that the investment in a security system is not wasted, as network cameras can easily identify intruders' faces and what they carry. Similarly, the high resolution of network cameras makes digital PTZ (pan-tilt-zoom) feasible.
4There is an increasing need to record, monitor, and search more video content globally, and intelligent video is a significant trend for the future. Advanced network cameras can incorporate built-in motion detection and alarm management functions, allowing the camera to decide when to transmit images, how often to update, and at what resolution, as well as when to notify designated operators to monitor and/or respond. Even higher-level computations, such as license plate recognition and people counting, can be integrated into network cameras. Smart camera levels allow for greater capacity and efficiency in security applications compared to DVRs or other centralized systems, and network cameras also address another emerging challenge: analyzing multiple channels using real-time computing capabilities. Network cameras come equipped with specialized and highly integrated hardware that performs excellently in image analysis tasks, making them more suitable for large-scale intelligent video system deployments.
5Whenever an analog PTZ camera is used, the sequence communication controlling PTZ movements requires transmission through cables separate from the video signal, which is very costly and complicates wiring. Network camera technology allows PTZ control to be transmitted simultaneously over the network that is carrying the video; using a network speed dome camera, PTZ control commands are issued directly over the IP network, resulting in significant cost savings and greater flexibility. Better yet, network cameras can also integrate input and output signals, such as accepting alarms and controlling door locks, meaning fewer cables, less money, more functionality, and easier integration.
6In certain applications, the importance of voice is increasing. In traditional analog systems, receiving audio is impossible unless you run a separate audio line to the DVR. Network cameras simplify this by allowing you to capture audio directly at the camera and synchronize it with the video stream or even integrate it into the same video stream before transmitting it to the monitoring side for simultaneous and/or synchronized recording over the network. Voice integration also allows users to conduct two-way conversations using microphones and amplifiers, making this powerful voice integration capability easy to install and cost-effective—something only found on network cameras.
7When we use analog cameras, video is transmitted over coaxial cables without encryption or authentication, making it easy for anyone to easily intercept images, tamper with them, or swap out videos from other cameras (think of the exciting scene in the movie Ocean’s Eleven). In a network video architecture, cameras can encrypt images before transmitting them over the network to ensure no one can directly view or alter them. Recording systems can also be set up to accept video only from designated network cameras through encrypted authentication, minimizing the possibility of intrusion. Furthermore, for future evidence convenience, network cameras can add "watermarks" containing time, location, user, alarms, or more information to the video data stream. Do analog cameras offer such advanced features? Sorry, they do not.
8Traditional analog video relies on expensive coaxial cables, proprietary fiber optics, or dedicated wireless transmission. These methods compromise image quality over longer distances, and adding power transmission, alarm input/output, and voice features complicates this dilemma. Standard IP-based digital systems overcome these obstacles at lower costs and with more options; for example, the images you view on certain websites from anywhere in the world are generated by digitally streamed images from network cameras without loss of quality due to distance. IP-based networks have established standardized technologies, meaning that costs can be significantly lower. Unlike analog systems, IP video streaming can send signals to every corner of the world using various easily accessible compatible networking infrastructure. Because it is based on packet-switching communication, multiple video streams can be transmitted simultaneously over the same line, and new constructions now use low-cost Cat.5 cabling, allowing a single line to transmit video streams at full rates exceeding hundreds when Ethernet speeds reach 1 Gigabit. Sounds tempting?
9In analog cameras, CCD sensors convert analog signals into digital images via an analog-to-digital (A/D) converter processed through DSP, then converted back into analog signals for transmission over coaxial cables. Finally, signals are digitized again for recording on the DVR. This process results in three conversions, and each conversion degrades image quality. In a network camera system, images are only digitized once, remaining in digital form thereafter—no unnecessary conversions, and the image quality remains intact.
10Every benefit discussed above impacts cost considerations. While the initial purchase cost of network cameras may be slightly higher than traditional cameras, comparing the unit cost per channel and the flexibility and performance offered by network cameras will likely lead you to abandon DVR systems. In many system architectures, the direct cost of surveillance systems based on network cameras can even be lower than analog systems, as the overall cost reductions from these network camera systems primarily stem from extensive use of industrial standard and open systems servers, which do not require dedicated hardware like DVRs. This also reduces management and equipment costs, especially in large systems where storage devices and servers account for a significant portion of the total solution cost. Another cost-saving aspect is the utilization of existing infrastructure; IP networks, such as the Internet, LANs, and various connection methods like wireless applications, are cheaper than traditional copper or fiber optics. Therefore, the last question you might oppose is also resolved. So, what are you waiting for?
If you are surprised why you have never heard analog camera suppliers tell you the benefits of network cameras, why not pass this article to your supplier if you don't know where to start.
According to industry analysis authority J.P. Freeman, the network camera market is the fastest-growing segment in the surveillance and security industry, and sales have surpassed analog cameras for the first time. Understanding and operating security management on IP networks is further exemplified in next-generation advanced security management. On the other hand, analog cameras severely underperform in flexibility and performance, failing to meet next-generation requirements. The image capture speed and intelligent deployment capabilities of network cameras far outpace DVRs, making new systems easier to expand, allowing consumers to use cost-effective industrial standard servers for recording and storing images, and enabling them to choose from a variety of image management and analysis software to achieve multiple purposes. This unstoppable trend forces us toward open system architectures while moving away from proprietary DVR specifications, combining the advantages of networking, image digitization, and camera intelligence, thus accelerating the adoption of network cameras and bringing more benefits.
蘊藏許多助人的知識與智慧。