【 Weak current College 】 video conference system camera selection-Power By 【 China power house network 】

<br> I. Background <BR> <BR> since 1996, along with various line network, the Internet and the popularity of the constant speed, and the collaborative business model under the market economy matures, video conferencing in China have been widely used and .promotion, made the video conferencing products flood the market has mushroomed. .<BR> <BR> As the core components of video conferencing, camera optical indicators, electrical performance and functionality directly affect the use of video conferencing video quality. .Therefore, how to choose a cost-effective cameras, the manufacturers and dealers is a topic of great concern. .<BR> <BR> Second, the camera in video conference system <BR> <BR> Video Conference System (VideoConferenceSystem), it constitutes a fundamental factor is the video, as a dynamic image capture devices, video conferencing cameras constitute .system essential for front-end equipment. .<BR> <BR> Dynamic image through the optical zoom lens, optical image sensing element mapping on the (commonly known as "optical target"), the formation of RGB optical signals, the control of the internal electrical wiring, through the image encoder, the output AV .composite video signal, and the separation of S-Video signals. .Video signal through the video capture (card) device to capture, officially entered the video conferencing terminal processes. .<BR> <BR> Some PC desktop video conferencing for the production of small cameras, commonly known as the "camera", you can use the parallel port (now eliminated), USB1.1, USB2.0, IEEE1394 and so on. .Such optical signals corresponding to the camera signal to the port Interface based on the data format specification, digital signal directly to the way entered into the computer for the software calls. .<BR> <BR> Video conference system is the core technology indexes the video signal clarity, smoothness. .Therefore, the camera output video signal directly affect the competitiveness of products in the market system. .<BR> <BR> Third, the camera performance <BR> <BR> cameras in common, according to the data interface can be divided into conventional cameras and digital cameras, the former output of a standard AV and S terminal signal .USB and IEEE1394 latter standard for communications. .<BR> <BR> 1. Conventional camera key performance indicators <BR> <BR> (1) CCD size (ImageSensor) <BR> <BR> different because the production process, CCD acceptable raw materials used in the etching .Accuracy is different, manufacturers have used the CCD size 1 / 4 inch and 1 / 3 inch two specifications, the recent signs of 1/2.7 and 1/1.8 inch inch size. .<BR> <BR> (2) CCD Effective pixels (EffectivePixels) <BR> <BR> effective pixel CCD sensor that can be affected by light signals, and converted into electrical signals the maximum area. .PAL system generally valid under the CCD pixels: 752 (H) × 585 (V). .<BR> <BR> (3) horizontal scan lines (HorizontalResolution) <BR> <BR> the CCD signal sampling device is the use of both vertical and horizontal direction of cross-positioning means to extract the single element of the RGB values, so the level of .and vertical scanning a direct impact on the accuracy of the precision of the image. .People often horizontal scan lines to measure the lens precision grade, used as a communications professional cameras, the value of more than 450 general requirements, the current 480 line of products to the market to the mainstream. .<BR> <BR> (4) optical zoom (LensZoom) <BR> <BR> target object of the reflected light signal through the optical lens group need to focus on the CCD to form a clear image, the optical lens group .with translucent glass, filter the manufacturers need to ensure that sex is a fundamental element. .<BR> <BR> In addition, the optical lens group of the ultrasonic motor driven optical zoom can be realized as a face of the most important indicators of the user. .Common multiples are 8x, 10x and 12x, a manufacturer of products introduced to the parameter can reach 22x. .<BR> <BR> (5) Digital zoom (DigitalZoom) <BR> <BR> digital zoom is calculated using the difference between the way software will be the formation of the current CCD image local sampling, the formation of the specified pixel signal. .Digital zoom ratio value depends on the effective pixel CCD chip and built-in DSP processing power, the manufacturers provide 10x and 12x are generally two steps of conventional indicators. .<BR> <BR> (6) Signal system (VideoSignal) <BR> <BR> signal NTSC and PAL formats are generally two types. .According to China's TV broadcasting and communication norms, China for PAL. .<BR> <BR> (7) signal output format (SignalOutputFormat) <BR> <BR> all common video signals are based on the AVVideo composite signal, and S-Video splits the signal two, signal quality is relatively higher than the latter .The former stable. .<BR> <BR> (8) N (SignalNoiseRatio) <BR> <BR> indicators to measure the video signal is the signal to noise ratio, that the signal can be extracted from the ratio of effective signal, sections of the market .SNR is greater than the camera 45dB. .<BR> <BR> 2.USB1.1/2.0 and IEEE1394 interface performance camera <BR> <BR> recent years, with personal popularity of desktop video conferencing systems, the use of USB and IEEE1394 camera as an image (commonly known as camera .head) input interface product after another. .<BR> <BR> USB camera with the current market share of over 95%, which accounted for the bulk of products using USB1.1, the performance of these products can be considered from the following aspects. .<BR> <BR> (1) sensor (ImageSensor) <BR> <BR> the market to use more USB camera CMOS, now the CMOS production process is optimized, the basic elimination of defects in the aging of components, parallel output .data flow, we call "second-generation CMOS". .<BR> <BR> Individual manufacturers have also introduced the use of CCD as a sensor products. .<BR> <BR> (2) Effective pixels (EffectivePixels) <BR> <BR> effective pixels that can be photo sensor signal, and converted into electrical signals the maximum area. .Common Effective pixels camera: 652 (H) × 487 (V), while the output video signal is generally less than the actual pixel value. .<BR> <BR> (3) data bits (ImageDataBus) <BR> <BR> median refers to the sensor data and processing components parallel processing between the number of data bits, are commonly used three 8,9,10 .The higher the value, the image of the sample and a corresponding higher output accuracy. .<BR> <BR> (4) signal format (SignalFormat) <BR> <BR> camera through the WDM driver, you can target programs to provide the video signal format, the basic with VGA (640 × 480), CIF (352 × .288), SIF (320 × 240), QCIF (176 × 144), QSIF (160 × 120) formats. .<BR> <BR> (5) N (SignalNoiseRatio) <BR> <BR> sections of the market camera SNR greater than 45dB. .Users in the actual test, they can observe the black background with white or gray spots if there is, and in the face before waving palms, observe whether there is cross-sectional images and the black line both ways, to do simple judgments. .<BR> <BR> IEEE1394 camera, the larger flow theory of transmission, but because of the brand of video conferencing hardware product does not provide for such software driver interface to support this interface products currently on the market less. .<BR> <BR> 3.PTZ camera <BR> <BR> present other performance indicators, video conferencing systems are often used PTZ camera as a standard accessory terminal session. .PTZ camera is actually a three-dimensional rotation by a mechanical head and a telescopic lens camera composition. .<BR> <BR> PTZ meaning of the English translation is P-PAN (horizontal rotation) + T-Tilt (Tilt) + Z-Zoom (depth of field expansion). .In this sense, PTZ cameras also include the following reference. .<BR> <BR> (1) horizontal angle range (HorizontalAngle) <BR> <BR> mechanical head angle in the horizontal plane can go to the range, the general design angle range ± 50 ° ~ ± 120 ° between. .<BR> <BR> (2) Vertical angle range (VerticalAngle) <BR> <BR> machine head can rotate in the vertical direction angle range, the general design angle range of ± 20 ° ~ ± 35 ° between. .<BR> <BR> (3) pan rotation speed (RotatorSpeed) <BR> <BR> cameras in use, speed of head rotation will affect the user experience for the image information, the speed should not be too fast, .rotational speed is too fast will lead to user confusion for the feeling of the image information. .<BR> <BR> 4. <BR> <BR> Camera remote control PTZ camera available in the market sections of the communication system based on functional requirements, provide remote control functions. .The remote communication feature to VISCA protocol as the core, providing the manufacturers of equipment and conferencing systems compatibility and interchangeability. .<BR> <BR> Fourth, video conferencing industry, the demand for the camera as a video conferencing system <BR> <BR> one of the most important basic parts, the camera and the system total demand is the corresponding total number of terminals, and it is a year manufacturers .Purchase the largest share of external components of terminal equipment. .<BR> <BR> Since 2003, with the surge of domestic manufacturers of video conferencing, and MPEG-4, MPEG-2 standard video conferencing system appears, manufacturers use for the camera function and raised the quality of the video signal .higher demand. .Including domestic Huawei, ZTE and other manufacturers, including giants, we have chosen to import products PTZ type camera as standard accessories, or recommended products. .<BR> <BR> The original manufacturers of video conferencing system requirements for the camera can be summarized as the following factors: <BR> <BR> (1) optical signal indicators; <BR> <BR> (2) video signal .signal to noise ratio; <BR> <BR> (3) the output video signal format; <BR> <BR> (4) rotation angle and rotation speed; <BR> <BR> (5) hand-held remote control functions and .distance; <BR> <BR> (6) the shape of the camera; <BR> <BR> (7) camera is used to support remote control and communication protocols. .<BR> <BR> According to the author's experience in the video industry, through the development of the industry on the analysis of video conferencing, personal video conferencing system that with the popularity and technological development, for supporting the needs of the camera of the following trends. .<BR> <BR> 1. High-definition video signals, high-speed <BR> <BR> end-user video conferencing products is one measure of image clarity and smoothness of the signal, which is the manufacturer of the product design requirements. .Meanwhile, with the MPEG-4, MPEG-2 high definition video conferencing system occur, and MPEG-2FullD1 introduced to the application of high-end video conferencing system, the quality of the video source signal to become the forefront of a technical bottleneck. .<BR> <BR> Therefore, the camera can output high-definition, high-speed video signal needs to be a first. .<BR> <BR> 2. Remote control, intelligent control <BR> <BR> distributed remote video conferencing system is a typical application mode to work, video conferencing, management and control model of the application of a basic link. .In the current application, the user can control the President of the Conference venue and the mode to select the remote camera control remote venue status. .We also can use the "target person voice Pursuit" and "targets facial features to follow," etc, to make meetings more in control of the camera simple. .<BR> <BR> Therefore, the camera's remote control (similar to: VISCA communication) and intelligent control design has also become a high-end video conferencing products, a function of demand for components. .<BR> <BR> 3. <BR> <BR> Cost-effective communications network conditions with the maturity of the video conferencing system has increasingly become an ordinary business communications and business approach. .Video conferencing system in the application of medium-sized enterprises has become a common phenomenon, and even some multi-branch private enterprises, are considering or have already installed the desktop video conferencing systems. .<BR> <BR> The popularity of the video conference system is an inevitable trend, but the resulting problem is that the video conferencing system to lower the price to end users in China can accept the psychological level. .Currently, PTZ cameras in the country the lowest cost is 5100 yuan bulk purchases, and basic accounting for half the cost of the end product of the hardware, resulting in the stubbornly high price of terminal equipment. .The camera cost-effective, and reasonable price is the video conference system manufacturers for parts of a very practical requirement. .<BR> <BR> 4. Function price comparison <BR> <BR> same level, with the popularity of public communications networks and computer processing speed of the series increased application of video conferencing systems to customers all over the surface but also a variety of industries, for .the demand for quality camera is also divided into several functions simultaneously the price level. .<BR> <BR> A Class: suitable for large conference system - 50 people around the venue to use. .<BR> <BR> Requires camera with high magnification optical zoom and digital zoom, video signal noise ratio, with PTZ control, remote control and on-site hand-held remote control device upside down and some even require intelligent control functions .. .<BR> <BR> Selection of such users are fully functional parts as the main considerations. .<BR> <BR> B categories: for medium-sized conference system - about 10 people to use the venue. .<BR> <BR> Requires camera with medium magnification zoom capability, rotating head can be controlled to provide on-site hand-held remote control, the user needs no special features. .<BR> <BR> The user to select the elements of such products include the function, appearance and price and other aspects. .<BR> <BR> C categories: suitable for small meetings system - about 1 to 3 people using the venue, the main user plane is a wide range of small-scale enterprises. .<BR> <BR> Required to provide basic video camera signal, to support the head rotation and field control. .<BR> <BR> These products into the market as a key element of product prices. .<BR> <BR> D categories: for individual users of office and entertainment use, the main supporting desktop video conferencing terminal. .<BR> <BR> Demand products compact size, the video signal stability, low prices. .<BR> <BR> Present, the domestic market "foreign brand" products are concentrated in the A class, does not appear suitable for the needs of Chinese users of other products. .<BR> <BR> Five, breaking the "foreign goods" market control bottleneck <BR> <BR> deeply appreciate the people in the industry, PTZ camera's "foreign legion" greatly affected the development of video conferencing industry, on the one hand from .price for a huge profit margins, while shipments and supply channels through, limiting the development of domestic manufacturers of products. .<BR> <BR> We all remember the 2003 outbreak of "SARS" epidemic during the night, PTZ cameras became popular, everyone is looking around the spot. .Even, a foreign brand of video conferencing products are available as supporting the camera is not in place, but not delivered to the user. .At this time, we realized that the survival of our products, an important aspect is controlled by others. .We believe that the video conferencing industry needs a new supplier of PTZ cameras, and requires its non-competition with the business background. .<BR> <BR> Currently, there are peers in the industry out of the video conferencing system development and sales, with its extensive industry experience and strong development capacity, turned to a full range of PTZ cameras and supporting product development, production .and sales. .Notice from its published products, we are delighted to see enough, and "foreign brand" competing products, its function and production processes are in line with the demand for video conferencing. .We hope that the emergence of the brand, the video conferencing industry for all manufacturers to provide more suitable for external accessories. .<BR> <BR> We all see clearly that China has a huge market of video conferencing users, from the telecommunications network operator service providers, to small and medium users, and even personal communications, and its huge market share is immeasurable .The. .<BR> <BR> At present, mainland China sales region in the video conference system manufacturers, including several from overseas brand products, and more than 20 brands of domestic manufacturers. .In this competitive environment, manufacturers not only have strong technical strength, the sales team, product features and quality with a strong effect, but also require the price to meet the user's purchasing power. .<BR> <BR> VI Conclusion <BR> <BR> video conferencing system as a modern means of communication, in real life has become an essential part of communication. .In this market, independent of national brand products should occupy a relatively important proportion. .In the industry chain, which links should not have been a single unit and institutional control, which is the overall development of the industry is poor. .<BR> <BR> PTZ camera for video conferencing as core components, on the one hand, it should be, and other external accessories, and video conferencing systems complement each other, from a technical and price products to support the development of video conferencing systems and user market continues to grow; .On the other hand, the user market for the development of PTZ cameras these accessories market has brought a huge market space, is the simultaneous development between the two. .<BR> <BR> We hope China's video conference system, to see more national brands of cameras. .<BR> <BR> <BR> <BR> <BR>.