Nowadays, there are not many cameras in private movie theaters, because now according to all the laws and regulations provides that private theaters during the business period and can not be installed in the private camera, to monitor us, because it will affect our own privacy, if you find out about This situation, to timely call 12315 for complaint processing, or directly to the business to complain, they will immediately feedback.
The case of clandestine photography:
One, the cell phone shooting method
Many articles mentioned that the curtains will be drawn, the state of total darkness, open the cell phone, filming the whole house, where to find the red dot, that there is a camera.
This situation can be found in the camera, to meet the two situations
1, the camera has infrared night vision, that is, in the dark environment, he can emit infrared, in the case of your eyes can not be seen, the shooting of infrared video, that is, the kind of gray is not a few images, this camera is generally larger, sneak peek at the camera is rarely used.
2, to shoot to the infrared camera issued by the red dot, the need for cell phone lens is not shielded infrared, the old cell phone, part of this feature, you want to detect your phone has no, on the head of the air conditioning remote control, that small bulb like things, shooting, see if you can see, if not see, indicating that your cell phone can not shoot.
So, in order to use the cell phone to shoot the hidden camera, need to meet the two points, the camera itself is to emit infrared radiation, the second, your cell phone can shoot infrared radiation, one of the two does not satisfy, that can not be photographed.
Two, infrared detector
Principle, is to use that string of lights, infrared light, after encountering the camera's lens, there will be reflections, which is like you against a hillside, looking for the sun shines, sniper lens reflections, if you think your eyes are good, you can find that, then I also have nothing to say. To put it bluntly, it is a setup, you believe, your wonderful video, may appear on some websites.
3, thermal imaging (究极大招)
真正能监测摄像头的，就是热成像
热像仪，是能把不同温度区域，在显示器上显示出来，温度有差别，颜色就不同
比如插座中间藏着一个 Camera, socket itself does not use electrical appliances, the temperature is room temperature, but the camera to work, it will heat up.
The camera will heat up, and although the temperature won't be too high, there will be a temperature difference, and it will show up, so that if you use a thermal imager and sweep around the suspicious place, you'll naturally find those little bright spots.
Civilian-grade thermal imaging cameras, there are two types, the first is handheld, larger, but a little better resolution.
Camera Introduction:
A video input device. Camera (CAMERA or WEBCAM), also known as computer camera, computer eye, electronic eye, etc., is a video input device, is widely used in video conferencing, telemedicine and real-time monitoring.
Ordinary people can also talk and communicate with each other via webcam on the Internet with images and sound. In addition, people can also use it for a variety of popular digital video, audio and video processing.
Classification:
Cameras can be divided into two categories: digital cameras and analog cameras. Digital cameras can convert the analog video signals generated by video capture devices into digital signals, which in turn can be stored in a computer. The video signal captured by an analog camera must be converted to digital mode by a specific video capture card and compressed before it can be converted to a computer. A digital camera captures the image directly and transmits it to the computer through a serial, parallel or USB port. The computer market camera is basically based on digital cameras, and digital cameras in the use of new data transmission interface USB digital camera is the main, most of the market is visible in this product. In addition to this there is a video capture card with the use of the product, but is not yet mainstream. Due to the rapid popularity of personal computers, the overall cost of analog cameras is higher, and can not meet the BSV LCD splicing screen interface and other reasons, the transmission speed of the USB interface is much higher than the speed of the serial port, parallel port, and therefore the market USB interface digital camera. Analog camera can be used with a video capture card or USB video capture card, it is very easy to connect with the computer to use, the typical application is general video surveillance. Clean area camera, clean area embedded special camera is a clean area clean room for real-time monitoring of important equipment key positions of the special camera. The camera flat panel, embedded in the color steel plate installation, zero health dead ends, easy to clean, easy to install, fast multi-point control, compatible with mainstream video systems.
Resolution:
Resolution is a parameter used to measure the amount of data within a bitmap image, usually expressed as dpi (dotperinch, dots per inch). Simply put, a camera's resolution is the ability of the camera to resolve an image, i.e. the number of pixels in the camera's image sensor. The highest resolution is the size of the camera's ability to resolve an image, i.e. the highest number of pixels in the camera. The resolution of the more common 300,000 pixel CMOS is 640 x 480, and the resolution of the 500,000 pixel CMOS is 800 x 600. The two numbers of the resolution indicate the unit of the number of dots in the length and width of the picture, and the aspect ratio of a digital picture is usually 4:3.
In practice, if the camera is used for web chatting or video conferencing, then the higher the resolution, the higher the cost of the web chatting or video conferencing. Therefore, consumers should pay attention to this aspect and choose a product with the right pixels for their needs.
Lens: Lens structure, composed of several lenses, plastic lens (Plastic) or glass lens (Glass).
Image sensor: can be divided into two categories
CCD (charge-coupleddevice): charge-coupled device
CMOS (complementarymetaloxidesemiconductor): complementary metal oxide semiconductor
Remote control:
Ordinary version
1, remote monitoring camera is a remote monitoring camera, the main division of the ordinary version, strengthened version and outdoor version of the three categories, you can left and right 320 degrees, up and down 60 degrees rotating monitoring, the screen to take pictures, video recording, and can be photos, video recording sent to the mailbox or FTP server, the camera has a motion detection function, you can set up to send an e-mail warning and so on. The most important thing is that there is no need to install wires and hardware, just a network cable, you can monitor the place you want to monitor remotely from any corner of the world.
2, the ordinary version of the network man remote monitoring camera is a combination of traditional cameras and network technology produced by a new generation of cameras, as long as the network man camera plugged into the network cable (without a computer), it can be the image through the network to the other side of the world. You can remotely control the camera left and right 320 degrees, up and down 60 degrees of rotation, for monitoring, and will monitor the screen recorded, sent to the mailbox or FTP server ... in your company or warehouse, store, home installation of a network of people cameras, then you even to the other side of the other place, as long as you can get on the Internet, you can also be monitored remotely. Ordinary companies to build a video control platform, no tens or hundreds of thousands of dollars can not be done, and can only be implemented in a fixed monitoring platform control (you can not be at home or in the field for control), and the purchase of the network man camera, easy to install (plugged into the network cable can be), no need to do the port mapping, the deployment of the cost of inexpensive, can be realized in the off-site monitoring.
Enhanced Version
(2) Compared with the ordinary version of the Network Man remote monitoring camera enhanced version of the Network Man remote monitoring camera enhanced version of the performance is more powerful, can easily realize the transmission of high-definition images of low network bandwidth, the image of the ordinary version of the camera is more clear, and to achieve night vision, audio transmission, and other new features, dynamic alarms, can be set up to alarm time zones, the exception of automatic recovery, The new features include dynamic alarm, programmable alarm time zones, automatic recovery from abnormalities, automatic connection after network interruption, etc.
(3) Outdoor version: network people remote monitoring camera outdoor version compared to the first two of its superior performance lies in the strong outdoor video surveillance features, and enhance the version is different, it uses a professional CCD sensor chip (420 lines), hemisphere enclosure, waterproof and high temperature resistant, suppression of glare, infrared night vision; can be adapted to the more severe outdoor environment, support for wireless routing, etc., commonly used in the wilderness areas, and the Internet is the best way to protect your computer from the heat of the day. It is commonly used in wilderness areas, forbidden areas, dangerous areas, such as construction sites, neighborhood villas, factories, vaults, construction sites and so on. It is the most suitable for monitoring the life of pregnant women in real time to protect their personal safety.
Working Principle:
The working principle of the camera is roughly as follows: the scene through the lens (LENS) generated by the optical image projected onto the surface of the image sensor, and then converted to electrical signals, through the A/D (analog-to-digital) converted to digital image signals, and then sent to the digital signal processing chip (DSP) in the processing, and then through the USB interface to the computer. The image is then transferred to a computer through the USB port and processed on the monitor.
Buying Guide:
From the composition of the camera to determine the quality of a camera from the hardware is mainly: lens, main control chip and sensor chip.
Lens:
Five layers of "full glass", but also the top camera lens. The composition of the lens is a lens structure,
composed of several lenses, generally plastic lens (plastic) or glass lens (glass). Usually the camera with the lens configuration: 1P, 2P, 1G1P, 1G2P, 2G2P, 4G and so on. The more lenses, the higher the cost; glass lenses are more expensive than plastic. Therefore a good quality camera should be used glass lens, the imaging effect is relatively plastic lens will be good. Most of the camera products on the market in order to reduce costs, generally use plastic lenses or half-plastic half-glass lenses (i.e.: 1P, 2P, 1G1P, 1G2P, etc.).
Sensor chip:
(SENSOR) is an important part of the composition of the digital camera, according to the different components are divided into.
CCD (ChargeCoupledDevice, charge-coupled components), is generally used in photography and videography in the high-end technology components, the application of mature technology, imaging effect is better, but the price is relatively expensive.
CMOS (ComplementaryMetal-OxideSemiconductor, metal-oxide semiconductor components) used in lower image quality products. It is less expensive and consumes less power than CCD.
The advantages of CCD are high sensitivity, low noise and large signal-to-noise ratio. But the production process is complex, high cost, high power consumption.
CMOS advantages are high integration, low power consumption (less than 1/3 of CCD), low cost. But the noise is relatively large, low sensitivity. Earlier CMOS on the light source requirements are relatively high, in the use of CMOS as a light-sensitive components in the product, through the use of image light source automatic gain reinforcement technology, automatic brightness, white balance control technology, color saturation, contrast, edge enhancement, and gamma correction, and other advanced image control technology, it can be close to the effect of the CCD camera.
In the same pixel CCD imaging tends to transparency, sharpness are very good, color reproduction, exposure can ensure basic accuracy. CMOS products tend to be generally transparent, weak color reproduction of physical objects, the exposure is also not very good.
High-end cameras are basically CCD light-sensitive components, mainstream products are basically CCD and CMOS equal, in general, or CCD effect is better, the size of the CCD element is more than 1/3 inches or 1/4 inches in the same resolution, it is advisable to choose a larger size of the component is good. Users can buy according to their own preferences.
First of all, do not use in the backlight environment (this CCD with), especially do not point directly to the sun, or "magnifying glass burning ants" tragedy will happen on your camera. Secondly, the ambient light should not be too weak, or directly affect the image quality. There are two ways to overcome this difficulty, one is to strengthen the surrounding brightness, and the other is to choose the minimum required illumination of the product, some cameras can reach 5lux.
Lastly, we should pay attention to the reasonable use of the lens zoom, do not underestimate the point, through the correct adjustments, the camera can also have the same function of the chip shooting. The market sales of digital cameras, basically CCD and CMOS is equally divided. By the market situation and market development and other restrictions, the camera using CCD image sensor manufacturers are few, mainly because of the high cost of using CCD image sensor impact.
Master Control Chip:
The choice of DSP is based on the cost of the camera, the market acceptance to determine the DSP design, production technology has gradually matured, the difference in the technical indicators is not very large, only some DSP in the subtle links and drivers to be further improved.
Pixel:
(Resolution) that is, sensor pixels, that is, we often say how many pixels of the camera, is an important measure of the camera is one of the indicators, some of the products will be in the box labeled with 30 megapixels or 35 megapixels. In practice, the higher the pixel of the camera, the better the quality of the images taken, but on the other hand, it is not the higher the pixel the better, for the same picture, the higher the pixel of the product it is the ability to analyze the image is also the stronger, but relatively the amount of data it records will also be much larger, so the requirements for the storage device is also much higher, and therefore in the choice of the current mainstream products. Due to the price of the camera, computer hardware, imaging effect and other factors, the market camera is basically in the 30 megapixel grade for sale. There is also due to the CMOS imaging effect in the high pixel is not ideal, so ruling the market of high pixel camera is still CCD camera. It is worth noting that some of the resolution markings refer to the interpolated resolution that these products can achieve using software, which can also improve the accuracy of the resulting image appropriately, but there is still a gap compared to the hardware resolution.
Capture speed:
Video capture capability is realized through software, and thus the requirements of the computer is very high, that is, the processing power of the CPU to be fast enough, followed by different requirements for the picture, the capture ability is not the same. Now the maximum resolution of the camera capture screen for 640 × 480, in this resolution no digital camera can achieve 30 frames per second capture effect, and thus the screen will produce the phenomenon of jumping. More realistic is in 320 × 240 resolution relying on the combination of hardware and software may reach the standard rate of capture indicators, so for the complete video capture speed, just a theoretical indicator. In addition to those mentioned above, you can also consider factors including the accompanying software, camera appearance, lens sensitivity, whether the built-in microphone and so on.
Maintenance tips:
1. Try to avoid pointing the camera directly into the sunlight, so as not to damage the camera's image-sensing devices.
2, avoid the camera and oil, steam, water, moisture and dust and other substances, and avoid direct contact with water.
3, do not use harsh detergents or organic solvents to wipe the camera.
4, do not pull and twist the connecting cables, including computer cameras and surveillance cameras:
5, non-essential, do not dismantle the camera yourself and try to touch its internal parts, which is easy to damage the camera, and once damaged the dealer is not expected to give warranty.
6, storage, the camera should be stored in a clean, dry place. Do not pull and twist the connecting cable, similar action may cause damage to the camera.
Debugging method:
Edit
In the embedded system of image processing, because it involves the processing and analysis of machine vision, it makes the debugging of the image generating tool camera more troublesome.
Introduction to vision:
Machine vision is the use of machines instead of the human eye to perceive and make measurements and judgments about the external environment. Through the imaging device (i.e. image acquisition device, divided into CMOS and CCD two kinds) will be taken into the target into the image signal, transmitted to the special image processing system, according to the pixel distribution and brightness, color and other information, into digital signals; image system on these signals to carry out a variety of operations to extract the characteristics of the target, and then according to the results of the judgment to control the field of the equipment action. In some of the system of real-time action requirements of the system is relatively high, the human reaction speed and information processing ability is unable to meet the requirements, and machine vision is easy to realize the information integration, and computer control system can improve the automation degree of the system.
The purpose of debugging:
The purpose of debugging a camera in an embedded system is to enable the mechanical and electrical parameters of the camera to produce image data of the highest quality while meeting system requirements. An imaging system that involves hardware and software, the quality of the imaging is often influenced by many factors from external disturbances and its own limitations that produce noise and uneven imaging. Factors from the software level is often a problem of the algorithm, this level of problems can be solved through theoretical analysis of mathematical calculations, from the hardware level of the factors to be debugged with the instrument, analyzed through experimental measurements in order to solve the problem, due to the hardware processing system at the bottom of the hardware quality will have a direct impact on the quality of the software, which affects the final quality of imaging. Debugging the camera is to try to eliminate interference from the hardware level.
Methods:
Because the embedded system is a broader concept, so this paper takes HCS12 as the main control chip camera group trolley debugging as an example of debugging methods are introduced.
(a) external build circuit connection CRT monitor
From the analog camera on the power, ground, signal three leads, the camera power supply, and then the video signal line to the TV box video input interface. The VGA-OUT of the TV box is connected to the CRT monitor, thus realizing the CRT display of the digitized camera vision. This method is a complete hardware level display, providing the same display effect as the human eye, which is of great help to the camera installation and correction of its own physical parameters.
(B) off-chip expansion of LCD liquid crystal
HCS12 series MCU contains a serial peripheral interface SPI (SerialPeripheralInterface), can realize the data transfer between MCUs, and its speed is faster than through the serial asynchronous communication (SCI) way. SPI module also supports MCU also peripheral devices between the two-way, synchronous, serial communication. The SPI module also supports bi-directional, synchronous and serial communication between MCU and peripheral devices, realizing peripheral expansion of MCU.
1. Display characters in the system operation in the form of characters to prompt the system-related operating parameters. Each character occupies a point column 8 * 6, 6 bytes of data are required to complete the character display only in the programming of the specified bit to write the corresponding data. Because the LCD module itself does not come with a font, so at the beginning of the program to define the ASCII table character LCD dot matrix data, that is, a size of N * 6 bytes of the two-dimensional array.
2. Display picture analog camera captured by the video signal after the MCU's A/D digitization, the information is stored in a 40 * 70 two-dimensional array, and then the array binarization, it will be able to be displayed in the 48 * 84 resolution LCD module, so that the developer of real-time observation of the camera machine vision.
This method is a combination of hardware and software display method, can real-time tracking display camera-related information, the display will not interrupt the system operation process.
(C) self-written serial communication host computer software
Using MCU's SCI module to send picture data to the PC, the host computer using MSCOMM control programming to read the communication data. After reading the data, you can use the windows program powerful data processing capabilities and picture display capabilities of the picture data processing, such as: according to the data on the picture redrawing, filtering analysis of the array and display filtering effect, will receive the array in the form of a file exported to the computer to provide a source of simulation data.
This method is a complete software display method, only to receive data from the MCU, you can realize a series of processing on the PC, to test the effect of graphical transformation, filtering analysis of the advantages and disadvantages as well as the idea of data simulation have other methods can not be compared to the advantages.
Comparison of advantages and disadvantages:
1. CRT adjustment method. By accessing the camera video signal, CRT can display machine vision with high fidelity. But can only be limited to the camera parameter testing and camera mechanical position adjustment, the advanced point of the digital signal will not be able to help.
2. LCD debugging method. Directly connected to the microcontroller SPI port for data transmission, real-time refresh display pictures, this module can be directly mounted on the system, real-time display of system-related information. However, due to the limitations of the module resolution, can only display black and white binary values, resulting in digital picture distortion.
3. Serial debugging method. Can make full use of the PC's powerful data processing and picture display function, can realize the digital picture of high-precision pixel display, and export the grayscale value table, for VC, MATLAB simulation to provide field data. However, the data transmission speed between PC and MCU is too slow, lack of real-time, lack of dynamic tracking advantages.
Automotive applications and automotive effects:
1. Passenger van reverse rear view
2. Passenger car interior (safety, door, luggage compartment) monitoring
3. Special vehicle image security recording and monitoring (bank money trucks, city vehicles, engineering vehicles, etc.)
4. Sedan reversing rear view
5. Sedan front view
5.
6. bus camera
Car Trends:
1. Car electronics from the audio application has been transitioned to the stage of multi-functional applications of audio and video. Camera is an important part of the car video.
2. With the popularization of rear-loading and front-loading of in-vehicle display, the camera is driven to popularize the application.
3. The globalization of automobile family popularization and driving and parking congestion, for the camera assisted reversing provides a lot of demand for space.
4. The humanized design of the car and customer demand, driven by the development and application of the technology and products. Some models have begun to configure camera products when they leave the factory.
5. The maturity of the camera technology itself and the adaptability of the vehicle environment, eliminating the technical bottleneck.
Application period:
1. Front-loading: synchronized with the car design, some models have been launched. For a period of time, the proportion is not large.
3.4S installation: special car-specific type of camera, synchronized with the car sales. Need to launch different products according to the car model, in order to achieve the purpose of beautiful installation and easy application.
3. After-market modification: generally use general-purpose cameras, lower prices. Domestic aftermarket channel sales and foreign trade sales are dominated by such products and applications.
Matching car sales:
1. Bundled with the rear-view mirror, full-auto screen and other displays;
2. Bundled with the visual reversing radar;
3. As a stand-alone product sales
Constraints on the development of the reasons for:
According to the development of hardware in the IT industry, "Moore's Law "According to the IT industry hardware development" Moore's Law, the digital camera also follow the same law of development, I believe that in the next few years will develop very quickly. From the market situation, factors restricting the development of the camera are mainly due to the following reasons:
1, the camera market started late, consumer awareness, acceptance is low, so the penetration rate is low, the market capacity to increase the speed is not fast enough, need to be guided by certain to promote market consumption.
2, the actual application of the camera is not broad enough, there are certain limitations, or as a consumer product in the sale, consumers just use it as a video chat, making a simple personal image set, a simple surveillance system and other tools.
3, computer hardware limitations, such as computer graphics cards, monitor resolution, USB1.1 interface speed, on the impact of the real popularity of high pixel camera.
Real application:
Widely used in agriculture, military, transportation and other aspects, the application is quite broad status is also very important, especially in traffic and security are very important
1. traffic management: have a camera so that the traffic management is more convenient and efficient
2. police crackdown: the camera in the police crackdown in the status of the police is very important. You can solve the case through the road cameras and neighborhood cameras.
Product Controversy:
Recently, according to CCTV reports, a large number of home cameras have been illegally invaded, so that the originally private family life scene, by strangers to peep, hunting. This news immediately made many people feel alarmed and angry. In fact, from manufacturers, hackers to regulators, to the network of "content" platforms and distributors, the existing law has set up a tight firewall. In the production and sales of home cameras, if the quality of the product is due to the intrusion, the manufacturers and merchants need to assume the corresponding legal responsibility. According to the Law on the Protection of Consumer Rights and Interests, operators should ensure that the goods or services they provide meet the requirements of safeguarding the safety of persons and property, and the right to privacy is an important personal right. For the family camera, the quality of its products is not only limited to the physical camera clarity, duration of use, but also includes the security of the built-in software and the reasonableness of the configuration program.