First, the lens
The lens is the first stage of video capture. The quality of the lens naturally affects the effect of the video. Although there are many kinds of lenses, it has a great impact on the video effect. The price of the lens ranges from a few tens of dollars to a few tens of thousands. However, in the field of surveillance, it is not enough to buy a few tens of thousands of shots, so basically the shots in the market are similar. However, the effect of the focal length of the lens on video effects is worth noting, which means that you should consider whether to choose the model of the interchangeable lens or choose whether to choose the zoom lens when you choose the product. Having said here, zooming means that the focal length of the lens can be changed. Some network cameras have the function of digital zoom. The digital zoom means that the video image can be zoomed in, which does not change the clarity of the image. It is of little value to the application of the network camera. Particular care must be taken in unscrupulous salespeople or JS stealing concepts.
Second, the image sensor
This is a key factor that affects video performance. At present, there are two types of CMOS and CCD on the market. In terms of imaging, the CCD has the same imaging transparency and sharpness under the same pixel, and color reproduction and exposure can ensure basic accuracy. Ordinary CMOS products tend to be generally transparent, and have poor color reproduction capabilities (the tones of the monitored object itself are different from those seen on the monitor, and are even completely discolored), and the exposure is not so good. Due to the nature of its own physical properties, there is still a certain gap between the imaging quality of ordinary CMOS and the CCD. CMOS video images are more artistic in art. Just like people take photos of art, everyone knows that artistic photos are very beautiful but not realistic. People are often confused by their artistic effects and ignore the importance of clarity and fidelity. In fact, when monitoring the industry, these two points are very important.
Third, video compression algorithm (also called video compression format)
This is the most important factor in the network camera, because it directly determines the video clarity, video smoothness and video storage space. After many years of understanding, this most important factor has always been avoided by the sellers intentionally or unintentionally. This may be due to the fact that they themselves have no way to tell the truth, or there are motives for inferiority. But as a savvy buyer, you must understand clearly. At present, the network cameras on the market mainly include H.264 and MPEG4 video compression algorithms. The former has stronger compression capabilities and less video loss, so it is clearer and smoother. The former can support a frame rate of 25 frames/second, and the latter generally does not exceed 10 frames/second. This means that the latter video is incoherent and not real-time; because the MPEG4 compression rate is not enough, if it is done in full real-time, the code stream is too large and it will be difficult to see the remote.
Fourth, the image format
The image format determines the actual pixel of the video image and is divided into two formats: DVD format, VGA (640*480) format and CIF (352*288) format. The DVD image format family contains D1 (720*576 interlaced scan), D2 ( 1048 * 720), D3 (1920 * 1080 interlaced), D4 (1280 * 720 progressive scan) and D5 (1920 * 1080 progressive scan) five image formats, currently on the market for the mainstream D1. Support D3 and The megapixels of the D4 are also on the market, but due to their larger bandwidth, applications are not yet widely available.
Different pixels of the same format are different, and the video file size is also different. If it is not the same image format, we cannot determine the advantages and disadvantages of the network camera based on the size of the hard disk required for recording. The image format of a network camera can often be adjusted, which means that if your hard disk space is not large enough but you need to record for a long time, you can achieve this by reducing the image format.
Five, frame rate
As we all know, any video file is composed of continuous pictures. One picture is called a frame. For example, a one-second video consists of 25 consecutive pictures. The frame rate at this time is 25 frames/second. Under the PAL system, 25 frames per second video can be very realistic and expressive. If it is less than 25 frames, the motion in the video will not be consistent enough, and the lower the more incoherent, even the jumping motion artifact will appear. Therefore, the frame rate is very important in video surveillance. This parameter will be displayed on the video monitoring interface. This parameter is also avoided by many professional salesmen. Everyone must pay attention to this when purchasing products, because the difference in the cost of the network camera that can support 25 frames per second is also greater.
Six, dual stream
Some webcams are designed to support two video signals, the so-called dual-stream. The advantage of dual-stream is that viewing with one stream and storing with one stream can prevent network congestion more effectively than watching and storing, thus better guaranteeing the smoothness of video over effective network bandwidth.
Seven, front-end storage
Some network cameras have an SD card slot or a USB removable storage interface, which we call front-end storage. Front-end storage is often used in monitoring environments where bandwidth is not sufficient. In some environments, it is not convenient to install broadband, use the functions of the front-end storage, and save monitoring videos to achieve a certain monitoring effect.
Eight, product line
In most of the larger monitoring systems, many types of products are often used, and it is difficult for the video management software of various manufacturers to be compatible with other brands of network cameras. Therefore, when choosing a brand for a monitoring system, it is necessary to consider whether the brand has a rich product line in order to be able to cope with the needs of various environments and system resolution capabilities. Such as support for infrared, support for WIFI wireless, support for POE, support for fiber access, support for PTZ, support for zooming, whether there is a video server so that it can be combined with some special analog cameras, and whether there is a video decoder to access the video wall.
Nine, software function
Most monitoring systems require centralized management. Therefore, whether video management software is powerful or whether the interface is friendly is also a problem that must be considered when selecting products. There are many functional modules of management software, so the identification of the advantages and disadvantages of video management software needs to be comprehensively considered. It is not possible to exaggerate a certain function or ignore a certain function. It is necessary to proceed with actual needs.
In addition to the above nine features, infrared night vision capabilities, ultra-low illumination, wide dynamics, strong light suppression and other functions are also some of the important parameters of the network camera. In summary, the selection of network cameras requires a certain amount of expertise and patience. If you don’t choose your own, you’ll want to choose the right IP camera for you.
The lens is the first stage of video capture. The quality of the lens naturally affects the effect of the video. Although there are many kinds of lenses, it has a great impact on the video effect. The price of the lens ranges from a few tens of dollars to a few tens of thousands. However, in the field of surveillance, it is not enough to buy a few tens of thousands of shots, so basically the shots in the market are similar. However, the effect of the focal length of the lens on video effects is worth noting, which means that you should consider whether to choose the model of the interchangeable lens or choose whether to choose the zoom lens when you choose the product. Having said here, zooming means that the focal length of the lens can be changed. Some network cameras have the function of digital zoom. The digital zoom means that the video image can be zoomed in, which does not change the clarity of the image. It is of little value to the application of the network camera. Particular care must be taken in unscrupulous salespeople or JS stealing concepts.
Second, the image sensor
This is a key factor that affects video performance. At present, there are two types of CMOS and CCD on the market. In terms of imaging, the CCD has the same imaging transparency and sharpness under the same pixel, and color reproduction and exposure can ensure basic accuracy. Ordinary CMOS products tend to be generally transparent, and have poor color reproduction capabilities (the tones of the monitored object itself are different from those seen on the monitor, and are even completely discolored), and the exposure is not so good. Due to the nature of its own physical properties, there is still a certain gap between the imaging quality of ordinary CMOS and the CCD. CMOS video images are more artistic in art. Just like people take photos of art, everyone knows that artistic photos are very beautiful but not realistic. People are often confused by their artistic effects and ignore the importance of clarity and fidelity. In fact, when monitoring the industry, these two points are very important.
Third, video compression algorithm (also called video compression format)
This is the most important factor in the network camera, because it directly determines the video clarity, video smoothness and video storage space. After many years of understanding, this most important factor has always been avoided by the sellers intentionally or unintentionally. This may be due to the fact that they themselves have no way to tell the truth, or there are motives for inferiority. But as a savvy buyer, you must understand clearly. At present, the network cameras on the market mainly include H.264 and MPEG4 video compression algorithms. The former has stronger compression capabilities and less video loss, so it is clearer and smoother. The former can support a frame rate of 25 frames/second, and the latter generally does not exceed 10 frames/second. This means that the latter video is incoherent and not real-time; because the MPEG4 compression rate is not enough, if it is done in full real-time, the code stream is too large and it will be difficult to see the remote.
Fourth, the image format
The image format determines the actual pixel of the video image and is divided into two formats: DVD format, VGA (640*480) format and CIF (352*288) format. The DVD image format family contains D1 (720*576 interlaced scan), D2 ( 1048 * 720), D3 (1920 * 1080 interlaced), D4 (1280 * 720 progressive scan) and D5 (1920 * 1080 progressive scan) five image formats, currently on the market for the mainstream D1. Support D3 and The megapixels of the D4 are also on the market, but due to their larger bandwidth, applications are not yet widely available.
Different pixels of the same format are different, and the video file size is also different. If it is not the same image format, we cannot determine the advantages and disadvantages of the network camera based on the size of the hard disk required for recording. The image format of a network camera can often be adjusted, which means that if your hard disk space is not large enough but you need to record for a long time, you can achieve this by reducing the image format.
Five, frame rate
As we all know, any video file is composed of continuous pictures. One picture is called a frame. For example, a one-second video consists of 25 consecutive pictures. The frame rate at this time is 25 frames/second. Under the PAL system, 25 frames per second video can be very realistic and expressive. If it is less than 25 frames, the motion in the video will not be consistent enough, and the lower the more incoherent, even the jumping motion artifact will appear. Therefore, the frame rate is very important in video surveillance. This parameter will be displayed on the video monitoring interface. This parameter is also avoided by many professional salesmen. Everyone must pay attention to this when purchasing products, because the difference in the cost of the network camera that can support 25 frames per second is also greater.
Six, dual stream
Some webcams are designed to support two video signals, the so-called dual-stream. The advantage of dual-stream is that viewing with one stream and storing with one stream can prevent network congestion more effectively than watching and storing, thus better guaranteeing the smoothness of video over effective network bandwidth.
Seven, front-end storage
Some network cameras have an SD card slot or a USB removable storage interface, which we call front-end storage. Front-end storage is often used in monitoring environments where bandwidth is not sufficient. In some environments, it is not convenient to install broadband, use the functions of the front-end storage, and save monitoring videos to achieve a certain monitoring effect.
Eight, product line
In most of the larger monitoring systems, many types of products are often used, and it is difficult for the video management software of various manufacturers to be compatible with other brands of network cameras. Therefore, when choosing a brand for a monitoring system, it is necessary to consider whether the brand has a rich product line in order to be able to cope with the needs of various environments and system resolution capabilities. Such as support for infrared, support for WIFI wireless, support for POE, support for fiber access, support for PTZ, support for zooming, whether there is a video server so that it can be combined with some special analog cameras, and whether there is a video decoder to access the video wall.
Nine, software function
Most monitoring systems require centralized management. Therefore, whether video management software is powerful or whether the interface is friendly is also a problem that must be considered when selecting products. There are many functional modules of management software, so the identification of the advantages and disadvantages of video management software needs to be comprehensively considered. It is not possible to exaggerate a certain function or ignore a certain function. It is necessary to proceed with actual needs.
In addition to the above nine features, infrared night vision capabilities, ultra-low illumination, wide dynamics, strong light suppression and other functions are also some of the important parameters of the network camera. In summary, the selection of network cameras requires a certain amount of expertise and patience. If you don’t choose your own, you’ll want to choose the right IP camera for you.
Fine Chemicals, Speciality Chemicals, Fine Chemical Additive
Dynasty Chemicals (NingBo) Co., Ltd. , https://www.dychemco.com