The functions of modern surveillance systems have long gone beyond mere video recording. Motion detection in the area of interest, counting and identifying people and vehicles, tracking objects in motion—today even the least expensive IP cameras are capable of all this. With a sufficiently powerful server and the necessary software, the possibilities of security infrastructure become virtually limitless. However, there was a time when such systems couldn't even record video.
From the Pantelograph to the Mechanical Television
The first attempts to transmit images over distance were made in the second half of the 19th century. In 1862, Florentine abbot Giovanni Caselli created a device capable of both transmitting and receiving images over electric wires—the pantelograph. However, calling this device a 'mechanical television' would be a significant stretch: in fact, the Italian inventor created a prototype of a fax machine.
Giovanni Caselli's Pantelograph
Caselli's electrochemical telegraph functioned as follows: the transmitted image was first 'converted' into a suitable format by drawing with non-conductive inks on a tin foil plate, which was then fixed with clamps onto a curved copper substrate. The reading head consisted of a gold needle, scanning the metal sheet line by line with a 0.5 mm step. When the needle was over an area with non-conductive inks, the ground circuit was broken, and current was supplied to the wires connecting the transmitting pantelograph to the receiving one. Simultaneously, the receiver's needle moved over a sheet of thick paper impregnated with a mixture of gelatin and potassium ferrocyanide. Under the influence of electric current, the connection darkened, thus forming the image.
This device had many drawbacks, among which low performance, the need for synchronization of the receiver and transmitter—on the accuracy of which the quality of the final image depended—and the labor-intensive and costly maintenance should be highlighted. As a result, the era of the pantelograph was exceptionally short. For instance, the Kazelli devices used on the telegraph line between Moscow and St. Petersburg worked for just over a year: having been put into operation on April 17, 1866, the day the telegraph service between the two capitals opened, the pantelographs were dismantled as early as the beginning of 1868.
Much more practical was the bildtelegraph, created in 1902 by Arthur Korn based on the first photoelectric cell invented by the Russian physicist Alexander Stoletov. The device gained international fame on March 17, 1908: on that day, a photograph of a criminal was transmitted from a police station in Paris to London using the bildtelegraph, which subsequently helped the police identify and apprehend the offender.
Arthur Korn and his bildtelegraph
Such a device provided good detail in photographic images and no longer required special preparation, but it was still unsuitable for transmitting images in real time: processing one photograph took about 10–15 minutes. However, the bildtelegraph found a place in forensics, where it was successfully used by police for transmitting images, composite sketches, and fingerprints between precincts and even countries, as well as in news journalism.
A real breakthrough in this field occurred in 1909: it was then that Georges Rignoux achieved image transmission at a refresh rate of one frame per second. Since the telephotographic device had a "sensor" made up of a mosaic of selenium photoelements and its resolution was just 8 × 8 "pixels," it never left the confines of the laboratory. However, the very fact of its appearance laid the necessary foundation for further research in the field of image transmission.
The Scottish engineer John Logie Baird truly excelled in this field and entered history as the first person to successfully transmit an image over a distance in real time, which is why he is considered the 'father' of mechanical television (and television in general). Given that Baird nearly lost his life during his experiments after receiving a 2000-volt electric shock while replacing the photoelectric element in his camera, this title is absolutely deserved.
John Logie Baird, inventor of television
Baird's creation utilized a special disk invented by the German technician Paul Nipkow back in 1884. Nipkow's disk, made of opaque material with a series of evenly spaced holes arranged in a spiral from the center of the disk, was used for scanning images as well as for forming them on the receiving device.
Nipkow disk device
The lens focused the image of the subject onto the surface of the rotating disk. Light passing through the holes struck a photoelement, thereby converting the image into an electrical signal. Since the holes were arranged in a spiral, each of them effectively performed a line-by-line scan of a specific section of the image focused by the lens. An identical disk was also present in the reproduction device, but behind it was a powerful electric lamp that responded to variations in brightness, and in front of it was a magnifying lens or system of lenses that projected the image onto a screen.
The working principle of mechanical television systems
Baird's device used a Nipkow disk with 30 holes (consequently, the resulting image had a resolution of just 30 lines vertically) and could scan objects at a rate of 5 frames per second. The first successful experiment in transmitting a black-and-white image took place on October 2, 1925, when the engineer managed to broadcast a half-tone image of a ventriloquist's dummy from one device to another.
During the experiment, a courier rang the doorbell, who was supposed to deliver important correspondence. Encouraged by his success, Baird grabbed the bewildered young man by the hand and led him to his laboratory: he was eager to evaluate how his creation would manage transmitting an image of a human face. Thus, 20-year-old William Edward Taynton, being in the right place at the right time, went down in history as the first person to be 'shown on television.'
In 1927, Baird conducted the first television broadcast between London and Glasgow (a distance of 705 km) over telephone wires. In 1928, the company founded by the engineer, Baird Television Development Company Ltd, successfully executed the world's first transatlantic transmission of a television signal between London and Hartsdale (New York). The demonstration of Baird's 30-line system proved to be the best advertisement: by 1929, it was adopted by the BBC and successfully used for the next six years, until it was replaced by more advanced equipment based on cathode ray tubes.
The Iconoscope — the harbinger of a new era
The world owes the invention of the cathode ray tube to our former compatriot Vladimir Kozmich Zworykin. During the Civil War, the engineer sided with the White movement and fled through Yekaterinburg to Omsk, where he worked on equipping radio stations. In 1919, Zworykin went on a business trip to New York. It was during this time that the Omsk operation took place (November 1919), resulting in the city being captured by the Red Army almost without resistance. With no way to return, he remained in forced emigration, becoming an employee of Westinghouse Electric (now CBS Corporation), which was already one of the leading electrical engineering corporations in the United States, where he simultaneously conducted research in the field of image transmission over distances.
Vladimir Kozmich Zworykin, the creator of the iconoscope
By 1923, the engineer had managed to create the first television device, based on a transmitting electron tube with a mosaic photocatode. However, the new management did not take the scientist's work seriously, so for a long time, Zworkin had to conduct research independently, under extremely limited resources. The opportunity to return to full research activities arose for Zworkin only in 1928, when he met another émigré from Russia — David Sarnoff, who was at that time the vice president of the Radio Corporation of America (RCA). Finding the inventor's ideas quite promising, Sarnoff appointed Zworkin as the head of RCA's electronics laboratory, and the project was finally able to move forward.
In 1929, Vladimir Kozmich presented a working prototype of a high-vacuum television tube (cathode ray tube), and in 1931, he completed work on the receiving device, which he named the 'iconoscope' (from the Greek eikon — 'image' and skopeo — 'to look'). The iconoscope consisted of a vacuum glass bulb, inside which a photosensitive target was fixed, along with an electron gun positioned at an angle to it.
Schematic diagram of the iconoscope
The photosensitive target, measuring 6 × 19 cm, was represented by a thin plate of insulator (mica), on one side of which microscopic (a few dozen microns in size each) silver droplets were deposited, numbering around 1,200,000, coated with cesium, while the other side had a continuous silver coating, from the surface of which the output signal was taken. When the target was illuminated, under the influence of the photoelectric effect, the silver droplets gained a positive charge, the magnitude of which depended on the level of illumination.
The original iconoscope on display at the Czech National Museum of Technology
The iconoscope formed the basis of the first electronic television systems. Its emergence significantly improved the quality of the transmitted image by vastly increasing the number of elements in the television picture: from 300 × 400 pixels in the first models to 1000 × 1000 pixels in more advanced ones. Although the device had certain drawbacks, including low sensitivity (requiring a minimum illumination of 10,000 lux for full shooting) and trapezoidal distortion caused by the misalignment of the optical axis with the beam tube axis, Zworkin's invention became a pivotal milestone in the history of video surveillance, largely determining the further direction of the industry's development.
The Transition from 'Analog' to 'Digital'
As is often the case, military conflicts have fostered the development of various technologies, and video surveillance is no exception. During World War II, the Third Reich actively developed long-range ballistic missiles. However, the first prototypes of the infamous 'revenge weapon' V-2 were not known for their reliability: the rockets often exploded on launch or fell shortly after takeoff. Since advanced telemetry systems did not yet exist, the only way to determine the cause of failures was through visual observation of the launch process, which was an extremely risky endeavor.
Preparation for the launch of the V-2 ballistic missile at the Peenemünde testing ground
To make the task easier for missile weapon developers and to protect their lives, German electrical engineer Walter Bruch designed what is known as a CCTV system (Closed Circuit Television). The necessary equipment was installed at the Peenemünde testing ground. This creation allowed scientists to observe the testing process from a safe distance of 2.5 kilometers, without risking their own lives.
Despite all the advantages, the Bruha video surveillance system had a significant drawback: it lacked a video recording device, meaning that the operator could not leave their post for even a second. The seriousness of this problem is highlighted by research conducted by IMS Research in recent times. According to its findings, a physically healthy and well-rested person will overlook up to 45% of important events just 12 minutes into observation, and this figure rises to 95% after 22 minutes. While this fact may not have heavily influenced missile testing, as scientists didn't need to stay in front of screens for hours on end, the absence of video recording capability significantly impacted the effectiveness of security systems.
This continued until 1956, when the first video tape recorder, the Ampex VR 1000, was unveiled, created by our former compatriot Alexander Matveyevich Poniatov. Like Zworkin, the scientist sided with the White Army, and after its defeat, he initially emigrated to China, where he worked for 7 years at an electric power company in Shanghai. He then lived for some time in France, before permanently relocating to the United States in the late 1920s, obtaining American citizenship in 1932.
Alexander Matveyevich Poniatov and the prototype of the world's first video tape recorder, the Ampex VR 1000
Over the next 12 years, Poniatov worked at companies such as General Electric, Pacific Gas and Electric, and Dalmo-Victor Westinghouse. However, in 1944, he decided to start his own business and registered the Ampex Electric and Manufacturing Company. Initially, Ampex specialized in producing high-precision drives for radar systems, but after the war, the company shifted its focus to a more promising direction—producing magnetic recording devices. From 1947 to 1953, Poniatov's company released several successful models of tape recorders that found applications in professional journalism.
In 1951, Poniatow and his chief technical advisors, Charles Ginsburg, Viter Selsted, and Miron Stolyarov, decided to go further and develop a video recording device. That same year, they created the prototype Ampex VR 1000B, which used the transverse scanning principle for recording information with rotating magnetic heads. This design allowed for the necessary performance level to record television signals at several megahertz.
Transverse scanning diagram of video signal
The first commercial model of the Apex VR 1000 was launched 5 years later. At the time of its release, the device was sold for $50,000, which was a substantial amount for that period. For comparison, the Chevy Corvette released the same year was offered for just $3,000, and this car was considered a sports car.
The high cost of equipment significantly restrained the development of video surveillance for a long time. To illustrate this point, it's enough to say that during the preparations for the visit of the Thai royal family to London, the police installed only 2 video cameras in Trafalgar Square (and this was for the security of the high-ranking officials), and after all events, the security system was dismantled.
Queen Elizabeth II of the United Kingdom and Prince Philip, Duke of Edinburgh, meet King Bhumibol of Thailand and Queen Sirikit.
The introduction of zoom, pan, and timer-activated rotation features has optimized the costs of building security systems by reducing the number of devices needed to monitor an area. However, implementing such projects still required a significant financial investment. For instance, the urban surveillance system developed for the city of Olean, New York, which was put into operation in 1968, cost city authorities $1.4 million, and its deployment took 2 years, despite the entire infrastructure consisting of just 8 cameras. Naturally, around-the-clock recording was not feasible at that time; the video recorder was only activated by the operator, as both the tape and the equipment were too expensive, making 24/7 operation impractical.
Everything changed with the spread of the VHS standard, thanks to the Japanese engineer Shizuo Takano, who worked for JVC.
Shizuo Takano, the creator of the VHS format
The format used azimuth recording, involving two video heads simultaneously. Each recorded one television field and had working gaps deviated from the perpendicular direction at an equal angle of 6° in opposite directions, which helped reduce cross-interference between adjacent video tracks while significantly decreasing the spacing between them, thus increasing recording density. The video heads were positioned on a drum with a diameter of 62 mm, rotating at a speed of 1500 revolutions per minute. In addition to the inclined video recording tracks, two audio tracks, separated by a protective gap, were recorded along the upper edge of the magnetic tape. A control track, containing frame synchronization pulses, was recorded along the lower edge of the tape.
When using the VHS format, a composite video signal was recorded on the tape, allowing for a single communication channel and significantly simplifying the connection between receiving and transmitting devices. Moreover, unlike the popular formats of those years, Betamax and U-matic, which utilized a U-shaped tape loading mechanism with a rotating platform—a characteristic feature of all previous cassette systems—the VHS format was based on a new principle known as M-loading.
The M-loading scheme of magnetic tape in a VHS cassette
The extraction and loading of the magnetic tape were accomplished using two guiding forks, each consisting of a vertical roller and an inclined cylindrical post that defined the exact angle at which the tape engaged the revolving head drum, ensuring that the recording track was angled properly to the base edge. The angles for the tape entering and exiting the drum were equal to the inclination of the drum's rotation plane relative to the mechanism's base, allowing both reels in the cassette to be in the same plane.
The M-loading mechanism proved to be more reliable and reduced mechanical stress on the tape. The absence of a rotating platform simplified the production of both the tapes and the VCRs, positively affecting their cost. Much of this contributed to VHS's decisive victory in the 'format war,' making video surveillance genuinely accessible.
Video cameras also evolved: devices with cathode ray tubes were replaced by models based on CCD arrays. The world owes the emergence of these innovations to Willard Boyle and George Smith, who worked at AT&T Bell Labs on semiconductor data storage. In the course of their research, the physicists discovered that the integrated circuits they created were susceptible to the photoelectric effect. By 1970, Boyle and Smith had presented the first linear photodetectors (CCD lines).
In 1973, Fairchild began mass production of CCD sensors with a resolution of 100 × 100 pixels, and in 1975, Steve Sasson from Kodak created the first digital camera based on such a sensor. However, it was nearly impossible to use since the image formation process took 23 seconds, and recording it onto an 8mm cassette took even longer. Additionally, the camera was powered by 16 nickel-cadmium batteries, making the whole setup weigh 3.6 kg.
Steve Sasson and the first Kodak digital camera compared to modern compact cameras
The main contribution to the development of the digital camera market came from Sony Corporation, particularly Kazuo Iwama, who led Sony Corporation of America at that time. He insisted on significant investments in the development of proprietary CCD chips, which allowed the company to introduce the first color CCD video camera, the XC-1, as early as 1980. After Kazuo's death in 1982, a gravestone was placed on his grave that contained a built-in CCD sensor.
Kazuo Iwama, president of Sony Corporation of America in the 1970s
September 1996 marked an event that can be compared in importance to the invention of the iconoscope. It was then that the Swedish company Axis Communications introduced the world's first "digital camera with web server features," the NetEye 200.
Axis Neteye 200 — the world's first IP camera
Even at the time of its release, the NetEye 200 was difficult to classify as a camera in the traditional sense. The device lagged behind its counterparts on almost all fronts: its performance ranged from 1 frame per second in CIF format (352 × 288, or 0.1 MP) to 1 frame every 17 seconds in 4CIF (704 × 576, 0.4 MP), and recordings were saved not as a single file but as a sequence of JPEG images. However, the main feature of the Axis creation was not the shooting speed or image clarity, but the presence of its own RISC processor, ETRAX, and a built-in Ethernet port 10Base-T, which allowed the camera to be connected directly to a router or a PC network card like a regular network device and managed using the bundled Java applications. This innovation led many manufacturers of video surveillance systems to completely rethink their views and determined the industry's general direction for many years.
More capabilities — more costs
Despite the rapid development of technology, the financial aspect remains one of the key factors in the design of video surveillance systems even after so many years. Although technological progress has led to a significant reduction in equipment costs, making it possible to assemble a system similar to the one installed in the late 60s in Oleane for just a few hundred dollars and a couple of hours of actual time, such infrastructure can no longer meet the dramatically increased demands of modern business.
This is largely explained by a shift in priorities. While video surveillance was previously used solely for ensuring security in protected areas, the primary driver of industry growth today (according to Transparency Market Research) is retail, which uses such systems to tackle a variety of marketing tasks. A typical scenario is determining the conversion rate based on the number of visitors and the number of customers who passed through the checkout counters. If we add a facial recognition system, integrating it with an existing loyalty program, we can gain insights into customer behavior linked to socio-demographic factors for the subsequent formation of personalized offers (individual discounts, bundled deals, etc.).
The problem lies in the fact that implementing such a video analytics system entails significant capital and operational costs. The stumbling block here is recognizing customers' faces. Scanning a face head-on at the checkout during contactless payment is one thing, but doing so in a crowd (in the retail space), from various angles and under different lighting conditions, is another. Here, only real-time three-dimensional modeling of faces using stereo cameras and machine learning algorithms can demonstrate sufficient effectiveness, which will inevitably increase the load on the entire infrastructure.
Taking this into account, Western Digital has developed the Core to Edge storage concept for Surveillance, offering clients a comprehensive set of modern solutions for video recording systems 'from camera to server.' The combination of advanced technologies, reliability, capacity, and performance enables the creation of a harmonious ecosystem capable of addressing virtually any task and optimizing the costs of its deployment and maintenance.
Our flagship product line consists of specialized hard drives for video surveillance systems, WD Purple, with capacities ranging from 1 to 18 terabytes.
The Purple series drives were specifically designed for round-the-clock operation within high-definition surveillance systems and incorporate the latest advancements from Western Digital in hard drive manufacturing.
- HelioSeal Platform
The higher-capacity models of the WD Purple line, ranging from 8 to 18 TB, are based on the HelioSeal platform. The enclosures of these drives are completely airtight, and the hermetic block is filled not with air, but with low-pressure helium. By reducing gas resistance and turbulence, the thickness of the magnetic plates was decreased, allowing for greater areal density recording using CMR methodology due to enhanced positioning accuracy of the read/write heads (utilizing Advanced Format Technology). As a result, switching to WD Purple provides up to a 75% increase in capacity within the same racks without needing to scale infrastructure. Additionally, helium drives are 58% more energy-efficient compared to standard HDDs due to reduced power consumption required for spindle startup and rotation. Further savings are achieved by lowering cooling costs: under the same load, WD Purple drives average 5°C cooler than their counterparts.
- AllFrame AI Technology
Even minor interruptions during recording can lead to the loss of critically important video data, making subsequent analysis impossible. To prevent this, the firmware of the Purple series drives includes support for the optional Streaming Feature Set section of the ATA protocol. Key features include cache usage optimization based on the number of video streams being processed and command read/write priority management, which minimizes the likelihood of frame drops and image artifacts. Moreover, the innovative set of AllFrame AI algorithms enables the operation of hard drives in systems that manage a significant number of isochronous streams: WD Purple drives support simultaneous operation with 64 high-definition cameras and are optimized for high-load video analytics and Deep Learning systems.
- Time Limited Error Recovery Technology
One of the common issues when dealing with high-load systems servers is the spontaneous failure of the RAID array caused by exceeding the allowable error correction time. The Time Limited Error Recovery option helps avoid HDD shutdown in the event that the timeout exceeds 7 seconds: to prevent this, the drive will send a corresponding signal to the RAID controller, after which the correction procedure will be postponed until the system is idle.
- The Western Digital Device Analytics monitoring system
Key tasks that need to be addressed when designing surveillance systems are increasing the uptime and reducing downtime due to failures. With the innovative software suite Western Digital Device Analytics (WDDA), administrators gain access to a wealth of parametric, operational, and diagnostic data concerning the status of the drives, allowing for the quick identification of any problems in the surveillance system, proactive planning of maintenance, and timely identification of hard drives that need replacement. All of this significantly improves the resilience of the security infrastructure and minimizes the risk of loss of critical data.
Specifically for modern digital cameras, Western Digital has developed a line of highly reliable WD Purple memory cards. The extended overwrite capability and resistance to adverse environmental conditions make these cards suitable for both indoor and outdoor surveillance equipment, as well as for use in standalone security systems where microSD cards serve as the primary data storage.
Currently, the WD Purple memory card series includes two product lines: WD Purple QD102 and WD Purple SC QD312 Extreme Endurance. The first line consists of four flash drive modifications ranging from 32 to 256 GB. Compared to consumer solutions, WD Purple cards have been specifically adapted for modern digital surveillance systems by incorporating a range of important enhancements:
- Water resistance (the product can withstand immersion up to a depth of 1 meter in fresh or saline water) and an extended operating temperature range (from -25 °C to +85 °C) allow WD Purple drives to be used effectively for both indoor and outdoor video surveillance devices, regardless of weather and climate conditions;
- Protection against static magnetic fields with an induction of up to 5000 Gs and resistance to strong vibrations and shocks up to 500 g completely eliminate the risk of losing critical data even in case of camera damage;
- A guaranteed resource of 1000 programming/erasure cycles allows for significantly prolonging the lifespan of memory cards even in 24/7 recording mode, thereby substantially reducing maintenance costs for the security system;
- The remote monitoring function helps to promptly track the status of each card and plan maintenance work more effectively, thus further enhancing the reliability of the security infrastructure;
- Compliance with UHS Speed Class 3 and Video Speed Class 30 (for cards with a capacity of 128 GB and above) makes WD Purple cards suitable for use in high-resolution cameras, including panoramic models.
The WD Purple SC QD312 Extreme Endurance line includes three models: 64, 128, and 256 gigabytes. Unlike the WD Purple QD102, these memory cards can withstand significantly greater loads: their operational resource is 3000 P/E cycles, making these flash drives an ideal solution for use in highly secured facilities, where recording takes place 24/7.
Source: habr.com
