Digital, digital system is a recent high frequency vocabulary, digital city, digital community and digital security wherefore, it is both a science and technology progress trend of, also has the conceptualization and hype of public opinion.
The concept of digital security is a fashion, it is the hot spot of attention, the pursuit of fashion, spin is the instinct of the media, however, lead the public opinion, the correct guidance is also the responsibility of the media. Security science and technology workers should be calm and think carefully and answer: what is the real meaning of digital security. Where the advantages of digital technology, find a correct direction of the security technology development and needs urgently to solve the key problems, help the user to make a reasonable choice.
The nature of the digital technology
The first thing to know clearly the nature of the digital technology: it is the sublimation of human understanding of objective things and expressions. Traditional analog power parameters to simulate the characteristics of things/sex, such as voltage and frequency to simulate the strength of the voice and tone; Every point on the space, the brightness is expressed as the charge. This information expression has reached a very high level, acoustic, television technology become the major means of understanding the objective world. However, when people have higher demand (high-fidelity sound, high-definition images), this way has been powerless or to pay a great cost.
In-depth study; Things most valuable information is contained in its change and the inner link. We are not in every point on the space, every moment in time to simulate, but to express their changes and the relationship between each other, will be more profound and more essentially reflect the objective things, get more complete, more accurate information, the expression can use the simple way to quantify (digital coding). This is the essence of digital technology. It shows our observation of the objective things, a more profound and accurate understanding, understanding and the expression method obtained the sublimation.
At the same time, the digital signal frequency can make full use of resources (energy evenly distributed) within a certain frequency band, high anti-jamming (distortion transfer process, does not affect the fidelity of information) and repairable (using error correction, fault-tolerant technology), hence, digital electronic technology is based on information technology as the core development inevitable trend, is known as the characteristic of the 21st century. On the basis of information technology, image technology of security technology of course. Based on the nature of digital technology, digital security technology should also inevitably lead to system obtain more accurate, more complete information, such as high quality images; To achieve high fidelity of information transmission, storage and replication (under the condition of limited resources). And security technology has always been the pursuit of this goal, unremitting solution topic.
Using digital technology to the traditional detection device to produce a detectable signal waveform, energy analysis, etc., can get real detection results, reduce the rate of false positives of system, the progress of detection technology in recent years is mainly using the results of digital processing technology;
At present, the output was not common digital camera, the digital technology and digital signal processing technology of the camera is very popular. DSP (digital signal processing (DSP), DPS (digital pixel sensor), double exposure technique, to realize the super wide dynamic range of the camera; Using the delay (accumulation), digital noise reduction (NR) technology, to improve the signal-to-noise ratio of the camera (S/N), the sensitivity, the poor environmental conditions to obtain a clearer, more rich details of image, are the benefits of digital technology. It makes wide dynamic, black and white/color conversion camera security system has the characteristics of the mainstream products;
Digital coding can be effectively compressed image signal data rate, makes the digital video storage and remote image transmission under the condition of narrow band. In fact, after the image coding data stream. Not only contains the brightness of the image information, but also contains the target movement way and the behavior characteristic information, which fully show the characteristics of the image information. Could become the basis of analysis of the image content further. Digital signal at the same time, the convenience of encryption, security, high security, very suitable for application in the field of security;
The modern access control system is developed on the basis of digital technology, it makes high uniqueness and stability of the application of biometrics is possible. (can also be cited many examples)
Must see: at present, we still have some shortcomings in digital technology, such as in the image quality, real-time, maturity and standardization of products, etc. Simulation system still has some advantages, such as local system). To seek truth from facts to make a choice, to the pursuit of the advantages of digital nature and higher goals, rather than the conceptualization as a slogan or trend to chase it.
The process of digital security technology
When it comes to security technology, digitization process naturally associated with the security technology phase or time division. The author insisted: digital is a process, can't say now digital or in a few years will be digital, more can't simply to system of a typical devices to date for security technology. For example, if a DVR just replace video tape recorder as a system of image storage device, it didn't bring any change to the monitoring system; Network monitoring system is the all information in the digital way, but it is the functions and the management and control mode of the system as well as the video matrix as the core of the simulation system and no essential difference. Really should be: the concept of digital essentially change security system information collection, transmission, analysis, data processing and system structure, configuration and control mode, make the security system from the previous stage (equipment) management is given priority to, is transformed into the later stage, with emphasis on the information analysis. Change the video monitoring system in the whole process of video signals generated by the camera is basically do not make any processing (classic) state, gradually become image detection and image content analysis as the core. System equipment to image processing equipment for the center with the camera as the center; Digital will gradually achieve security system of the seamless connection between all kinds of technical equipment and subsystems in (using a common transmission medium or communications platform), and on the unified operation platform, realize the management and control of all functions of the system. So say: not a digital or the replacement of several devices, or network structure changes; But the system internal information processing or identify the change process.
Now the current security technology in the process of the digitalization of two levels:
A plane is in the system USES the digital equipment and equipment using digital technology. Had told some of the above, security products using digital technology to effectively improve product functionality and performance, and the application of digital equipment is gradually changing the security system of the form. Among them, digital video record (DVR) is the equipment should be noted, it not only has the function of image storage (replace analog video tape recorder), also has the image combination, motion detection, alarm interface, front-end control and network functions, is the control of the small and medium-sized security system and node of the distributed system equipment.
Another level is a (full) digital system structure and application of the model. Digital system, especially in the system of full digital, there is no clear definition. We might as well refer to the concept of TV technology, both in the system all information (including data, audio, video, control), are all digital way. Use (public) network platform of remote monitoring and alarm system is a digital security system, its advantage is low cost (distance) of the transmission and can independently generated by the system structure, but the real advantage of the digital has not show it.
To sum up, digital, from analog to digital transformation can not completely dating thing, but a combination of both, the fusion of gradual evolution process. In the process, the concept of digital security will be more clear and perfect. Security system will be based on a new technology and environment, the nature of ascension and change.
Digitalization is the only way for the intelligent
Intelligent system not respectively, reflect the change of various physical quantities and state in isolation, but thoroughly, from the correlation between them and the characteristics of the change process to analysis and judgement, thus the real results. This requires systems and equipment adopts humanized design, with functions of simulate human thinking method of analysis, and judgment. Digital technology and digital is the foundation of implementing such system. Some of the current security system the function of the intelligent is using digital technology to achieve, for example: analog system to analyze the relations between the various detection data (time, frequency, speed, order, spatial distribution, etc.) to make a report to the police.
Adaptive system is not simply setting a threshold, and the various environmental factors are combined as a background, based on the analysis of target, to realize the real detection.
These in a simulated way is difficult to realize the function of the now common for the "double guide" detector, multi-dimensional video detection system, leakage cable detection system, and other products have.
Intelligence is the concept of advancing with The Times, is the highest level of automation, its real meaning is: independent, optimization control and efficiency, the coordination interaction. Security system of the intelligent can be understood as: to realize the detection of real; To realize all kinds of information and features (different definition and carrier) automatic analysis and recognition; System linkage accurate, coordinated interaction between institutions and related systems. All these must be on the basis of the digital technology can be realized, and the nature of digital embodiment.
Security system has the function of "early warning" intelligent is the highest state, the role of digital video technology is very important. Image content analysis and will make the image feature recognition system has found that some of the signs of events, function to predict the tendency of the incident, the monitoring and control system has the ability of forecasting (p). At the same time, security systems in many failed to solve the problem of long-term will get the answer, on the basis of the digital video to clarify many ambiguous concept. It will be set to detect (image content analysis), feature recognition and image control into an organic whole, become the core of the new concept of security system technology.
At this arrow led by information technology, many different kinds of professional development for a goal, many subjects and technology on the different way the way of law, this is the big trend in today's technology integration. At the same time, many related technology from its own demands, naturally put forward their own security solutions, security has become a matter of many technical source. Security guard against this concept is becoming more and more fuzzy, security technology is becoming more and more to not clear boundaries. In this environment how to highlight the characteristics of the safety technology and grasp the development direction of security technology, it is very important. Security technology in the process of its development and progress, always around a core, and this is "detection". "Detection, the detection of reality, to achieve early detection" is a process of security technology. Will is the process of digital proof system.
