Posts Tagged ‘ digital video images’



CMOS vs CCD

Written By:
Monday, January 9th, 2012

Charge Coupled Device (CCD) and Complementary Metal Oxide Semiconductor (CMOS) both have image sensors that are used for capturing digital images, but it is the technologies that are different. They each have their own set of strengths and weaknesses that give way to various applications. It is not as if one is superior to the other, but when you speak to vendors who only specialize in one of the forms of technology they will tell you that they feel otherwise. Throughout the last five years, there have been a lot of changes that have happened from both forms of technology. There are a lot of projections in regards to the demise of the technologies that have been proven false time and time again. Both forms of technology have a bright future, but there is still a need for the framework to be enhanced in regards to both of the CCD and CMOS imagers for their strengths and opportunities that they are going to be able to offer.

CCD or CMOS

Light is converted into an electric charge that can be processed into an electronic signal through both of the imagers. Within a CCD sensor, each and every pixel’s charge has to be transferred through an extremely limited amount of output nodes, which at many times is only one. It is then converted into voltage, buffered, and sent as an analog signal from off the chip. This allows all of the pixels to be devoted to capturing light, while the output’s uniformity, which is crucial to the quality of your images, is high. On the other hand, a CMOS sensor is designed where each and every pixel has its own conversion from charge-to-voltage. The sensor will often include the use of amplifiers, noise correction and circuits that are digitized, which allow the chips to output bits of digital information. This allows the design complexity to be increased, while the area for light capturing is reduced. Uniformity is lowered because each pixel is actually doing its own conversion, but the chip could be built to need a smaller amount of off-chip circuitry for its basic operations.

CCD vs CMOS

Left: CCD ---Right: CMOS

During the late 1960s and early 1970s both of the CCD and CMOS imagers were invented. It was DALSA founder Dr. Chamberlain, who was also the CEO, which developed both of the technologies. CCD originally became the more dominant of the two technologies. It was due largely in part to the fact that it gave more exceptional imaging with the technology that was available. The imaging sensors used in the CMOS technology ended up requiring more uniformity and had smaller features beyond what the silicon water foundries were able to deliver at that time. It wasn’t until the 1990s that lithography was developed so designers could begin making their case for the CMOS imagers once again. There was now a renewed interest in CMOS that was based on the expectations of lower price consumptions, a camera-on-a-chip integration, and lower costs for fabrication due to the reusing of mainstream logic and fabricating for memory devices. Even though these benefits are only possible in theory, it will take a lot more time and money to be able to put them into practice at the same time as they are delivering a higher image quality. There is also going to be an additional process for adapting these changes into effect for the original projections.

When the imagers are designed properly you are going to get exceptional imaging performance from both the CCD and the CMOS imagers. In the photographic, scientific, and industrial applications CCD has provided the benchmarks for the performance in the highest image qualities while at the expense of the quality of images, which is also measured in quantum efficiency and noise. If you look at the CMOS imagers, you are going to find more integration, a lower dissipation of power and a smaller system size possibly. However, they often have tradeoffs that are required between the quality of the image and the cost of the device. There is really no clear line between the different types of applications that each one can serve. The designers of the CMOS technology have devoted a lot of their time and efforts into achieving high quality images, but the CCD designers ended up lowering their pixel sizes and the power requirements for their power. You are going to find a low-cost and low-power cell phone camera in the CCD technology, while the sensors in the CMOS technology are going to offer high-performance cameras for professional and industrial use, which directly contradicts all of the earlier stereotypes. The producers that have succeeded in producing the crossovers have years of experience rooted deeply in both of the technologies.

CMOS vs CCDAt the chip level the costs are very similar for both the CCD and the CMOS. Early on the proponents of CMOS were claiming that the CMOS imagers were going to be a lot cheaper. They were supposed to be able to produce the same type of high-volume wafer processing lines as the mainstream login or the memory chips, but this has not been the case. The CMOS designers had to develop specialized, optimized, and lower-volume processors that are mixed-signal fabrications in order to accommodate the requirements for good imaging. It was very similar to that of the CCD designs. It has become a very slow and expensive process to be able to provide the processes at a successful lithography node that is smaller. There is an advantage to those who have a captive foundry because they are able to maintain the attention needed by the process engineers.

There are fewer components and less power that is required to operate the CMOS cameras, however, they are still going to need companion chips in order to have the optimal image quality. This process results in a higher cost and helps to reduce the advantages that are gained from lower power consumption. The CMOS devices are a lot more complex than the CCD devices, so they are going to cost a lot more to design them. The fabrication processes of the CCD tend to be a lot more mature and optimized. As a result, it is going to cost less to fabricate and design a CCD over a CMOS imager, in regards to a high-performance application. One of the most dominating influences of the device cost is the wafer size. The larger the wafer size is, the more devices it is going to be able to produce, which means the cost per device is going to be significantly reduced. The majority of the CMOS foundries are going to offer a 200mm device, whereas, the CCD foundries tend to offer a 150mm device. The majority of the captive foundries are going to use 150mm, 200mm, and 300mm for the production for the CCD and the CMOS devices.

CMOS AnalogBeyond the pricing issue, you also have to worry about the sustainability potential. CMOS was priced below their actual costs in order to win business because they were trying to pursue a high volume and commodity applications from a limited base of various businesses. For some of those businesses, the risk that they took ended up paying off and the volume that was produced was enough to maintain a margin for viability. There were some businesses that ended up having to increase their costs, but others ended up going out of business completely. Some of the venture capitalists find high-risk startups to be interesting, whereas, imager customers are going to require a long-term support and stability plan.

There have been problems with the arrival and development of the on-chip integration, but speed is one of the areas where the CMOS imagers are able to demonstrate a considerable amount of strength. Cost advantages have been difficult for everyone to realize, but they do have a relative ease of use in the output structures that are parallel. In terms of industrial applications they are going to have great potential.

The CCD and CMOS imagers are going to remain complementary to each other. It is not so much a matter of the technology, but rather the choice is going to depend on the vendor and the application that they choose to use. There is one company that is going to remain technology neutral when it comes to the two options available to them. Teledyne DALSA’s is one of the few vendors that are able to offer real solutions with both of the CCDs and the CMOS technologies.

Even though there are a lot of differences between the two imagers, it is always going to remain in the hands of the vendor to decide which product they want to offer consumers. Everyone is going to have a different opinion of which imager is going to be the best one for them, but there is really no clear and definitive answer as to what the best option is. Take the time to go through what each one has to offer and try to make the most informed decision that you can, based on what exactly it is that you are looking for.

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DVR CCTV System

Written By:
Friday, September 16th, 2011

The Digital Video Recording Closed Circuit TeleVision system or DVR CCTV system is rapidly becoming one of the most popular security and surveillance documentation and monitoring tools in use today.  Thanks to advancements in digital technology, not only is high-quality color digital video possible, but its also economically priced, easy to install, and versatile in application.  In addition, these systems are even able to record clear videos in total darkness using infrared technology.

A DVR CCTV system is any system that captures digital video images and records them on some type of storage medium for later use.  The difference between a digital video recording system and an analog video recording system is how the video image signal is created; however this lends itself to other differences such as how the video “footage” is stored, how it is transmitted, and what kinds and types of images are available.

Let’s look at how an older analog video recording system works, then we’ll compare it with the newer digital video recording system.  Both systems have a camera that “captures” the video images and a recorder that stores those images for playback at a later time.  Each system may also use monitors to display real-time (live) video as it is captured.

Without getting too technical, an analog digital video camera contains a sensor chip called a Charged Coupled Device or CCD or a Complementary Metal Oxide Semiconductor or CMOS.  These sensors convert the image’s light energy, which is focused onto it by the lens, into electrical energy that can be measured and used to create a video image.  The images are transferred from the camera to the video recorder and monitor using a coaxial video transmission cable.

The analog video recorder records the audio and video as magnetic signals, usually on a magnetic tape.  What is actually happening is that the camera is taking several pictures per second but it appears to the human eye as smooth motion video.  This is the same way its precursor, film video works.

Film cameras actually take several film pictures or photographs per second.  Once the film is processed or “developed” a projector rolls the film from the full reel to an empty one.  As the pictures pass in front of the projector lens in rapid succession, they give us the impression of a moving video.  Since film is basically a linear storage device that can be hundreds of feet long, the term “video footage” was used to refer to motion pictures.

Since analog video is stored as a magnetic pattern, each time the recorded video is played it has the potential for degrading the signal.  In addition, time can also degrade the magnetic signal as the signal’s weaker points can fade.  Analog video is stored on a variety of formats but the most popular magnetic video tape is VHS or BETA.  The video recorder either uses a video tape loop that re-records after reaching the end of the tape or individual video tapes that must be replaced when the recorder reaches the end of the tape.

Digital video recording systems use basically the same technology to create digital video.  Onenote of interest is that digital system’s files start out as analog signals in the camera and must be digitized by the camera before leaving it.  Cameras record (with the advent of digital imagery, the term “record” is also used synonymously with “capture”; meaning that the camera “captures” light images) image light energy and transfer it into electrical energy.  However, the fundamental difference in a digital video camera is that the camera also contains an analog-to-digit converter which turns the analog video signal into a series of 1s and 0s, or in other words, digital data.

This simple change has revolutionized the security camera industry.  Since the digital video signal is now stored as a digital file, many other technological changes have taken place that have made DVR CCTV systems differ from their older analog parents.

DVR CCTV systems have become so popular that they are now the norm in the security video industry, rather than the exception.  If you are interested in learning more, check out Security Camera King’s “CCTV Learning Center.”

 

 

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Hidden Camera With SD Card

Written By:
Wednesday, February 9th, 2011

There are times when covert camera monitoring and recording are necessary and one of the best devices for this purpose is a hidden camera with SD card. Thanks to recent technological advances in the computer world as well as in general electronics, a camera can be made as small as to fit in the shell of an average writing pen.

When it comes to the appearance of a hidden camera with SD card, there are many types from which to choose. These cameras come in “bare-bones” mini versions, where the camera is basically undisguised but is small enough to be hidden, to disguised versions that look (and often times function) as clocks, mirrors, safes, stuffed animals, and many more.

But what exactly is a hidden camera with SD card and how is it able to work? We’ll answer those questions and more in the following article.

The secret behind the success of the hidden camera with SD card is its incredibly small size. Another technological feature is its relatively low demand for power consumption. Yet another is the ability to save digital video images to an SD card, a relatively small device that can pack a big punch in memory capacity these days. Let’s start from the beginning.

A digital video security camera system works by capturing color digital video images with the camera, transmitting those images to the Digital Video Recorder or DVR unit, and saving them on the DVR’s hard disk drive and or displaying them on a monitor. Technically, a monitor is only needed for the system to set it up; that is, fine tune and adjust initial settings. However, if the user wants to monitor the digital video live (or later) the monitor will be needed. The important point here is that a digital video system can consist of just a digital video camera and DVR.

Basically that’s exactly what a hidden camera with SD card is; a digital video camera with a DVR. The key component of the digital video camera is the sensor that is used to create the digital video image. One of two different types of sensors, a Charged Coupled Device or CCD or a Complementary Metal Oxide Semiconductor is used. Generally speaking, a CCD provides the highest quality image at the price of power consumption while a CMOS provided a good quality image at a much lower demand for electrical power.

As technology continues to increase, the power demands for the CCD become much less and the quality for the CMOS becomes even better. Since many hidden cameras with SD card are standalone units placed inside other objects to disguise their appearance, power consumption may be an issue. For that reason many hidden camera with SD cards use CMOS sensor chips.

Although the CCD and the CMOS work a little differently, they both produce the same outcome, a relatively high-quality digital video image. They do this by transferring light images into electrical impulses. These impulses can be measured and compiled into data that creates a digital video image.

One of the most impressive features of digital video cameras is that they can produce these high quality digital video images with a CCD or CMOS the size of a square that is only 1/4 inch! In addition, a wide angle lens is usually used to focus the image on the sensor and these lenses are often as small as 3.7 mm in diameter. Obviously, the small sensor chip and lens combination “paves the way” for camera to be used in other devices as a hidden or disguised camera.

After the camera has created the data for a digital video image micro-circuit technology take over from there. First, an on-board analog-to-digital converter chip transfers the analog data into digital data. Then another circuit compiles and condenses the data to create a digital video file. The digital video file is saved by the DVR, however this cameras DVR records to an SD (Secure Digital) card instead of a hard disk drive.

SD cards are non-volatile memory containers that are used in many electronic devices such as cameras, cell phones and MP3 players. All the user has to do is remove the SD card, plug it into their computer, and download the digital video file created by the hidden camera with SD card.

On-board power for hidden cameras with SD cards may be supplied by a battery, or the camera may actually tap into the power of the device in which they are hidden.

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Digital Surveillance Software

Written By:
Wednesday, February 2nd, 2011

The term “digital surveillance software” refers to a broad category of computer based sets of instructions that provides the instructions for either a computer or a computer based device to operate, control, and/or process binary (digital) data used or created for security and surveillance purposes. To narrow this definition down a little for the purpose of this article, digital surveillance software is the collective set of programming used to create digital video images for security and surveillance purposes.

Since the words “digital surveillance software” refer to such a broad definition, it may be easier to explain what it is based on how it is used and what it does. There are basically three broad categories of digital surveillance software. The first applies to standalone digital video security and surveillance systems; the second applies to personal computer based digital video security and surveillance systems; and the third and final category, for the purpose of our discussion, applies to smartphones and similar type devices used with digital video and surveillance software.

Standalone Digital Video Security Systems
A standalone digital video security system is a set of devices that are used for security or surveillance purposes to create digital video files that may or may not be recorded. The term “standalone” indicates that these systems do not require any additional assistance from exterior devices such as a computer. The digital surveillance software used in these systems can include the operating system of the Digital Video Recorder’s or DVR’s and any additional programs used on that system to control the various devices of the standalone system

A standalone digital video security and surveillance system in its basic configuration includes one or more digital video cameras, a DVR unit with a Digital Signal Processor or DSP, and a digital based monitor. In a standalone system, the cameras send their digital video data to the DVR where the DSP compiles the data using a CODEC or COmpression/DECompression utility to create digital video files. The files are then viewed on the digital monitor and or stored for later use on a hard disk drive on the DVR.

The digital surveillance software in this system can include:
1) The operating system of the DVR/DSP unit;
2) The CODEC utility program; and,
3) Any other specialized set of instructions to control the equipment.

For example, Security Camera King offers three major types of DVRs; our Elite mini series, or Elite series, and our Ultimate series. These standalone systems have a highly specialized DSP that creates digital video files and coordinates the functions between the three major devices of the system. This is usually referred to as the “operating system” and all of our units use a Linux based operating system.

The CODEC utility is a specific software program that is used to compile the video data into a digital video file. Digital video is actually several digital photographs taken in succession. Different rates may be used but a general standard is 29.9 frames per second or fps. This means the camera takes 29 digital pictures in one second so in one minute of video, the camera takes approximately 1800 pictures. You can see how the file size can become enormously large in a very short period of time.

The CODEC uses mathematical algorithms so the file size is a fraction of the original total size. This piece of digital surveillance software does this with very little loss of quality. There are many different types of CODECs such as MJPEG, MPG, H.264, etc.

A standalone system may also contain digital surveillance software that operates the equipment, including specialized functions. For example, Pan-Tilt-Zoom or PTZ cameras can move horizontally, vertically, and can enlarge objects. These movements may be controlled by digital surveillance software.

Personal Computer Digital Video Security Systems
There are digital video security systems that utile a personal computer to take the place of the DVR, DSP, and or monitor. Normally these systems contain a PCI card or similar printed circuit board that performs the bulk of the systems needs including storing the digital video files, controlling devices, and displaying the video on the computer’s monitor.

Any of the software associated with these functions, in essence, can be considered digital surveillance software.

Smartphones
Smartphones require small programs in order to adapt or interface with different systems and devises. These programs are called applications or “apps.” An app can also be of a digital surveillance software type.

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Wireless IP Security Camera

Written By:
Tuesday, January 25th, 2011

One of the more recent digital video security camera system components is the wireless IP security camera. These cameras use the Internet as a network medium for the purpose of transmitting their digital video images and for allowing the user to control the camera remotely. This places the maximum power of remote accessibility as well as easy installation in the hands of the user.

It seems as if all of our electronic devices today utilize or have some sort of affiliation with, the Internet. So why shouldn’t the digital video security industry take advantage of its seemingly ubiquitous presence and cost-efficient use as well? That’s exactly what a wireless IP (Internet Protocol ready) security camera does.

By using a wireless IP security camera you can monitor your business in Ft. Lauderdale while on vacation in Tokyo. If you have a Pan-Tilt-Zoom or PTZ wireless IP security camera you can even control the camera from Tokyo moving the camera horizontally, vertically, or even zooming in on an object. You can do all this anywhere there is a broadband Internet connection and an available desktop or laptop computer and even using a 3G or 4G smartphone.

How is this possible? In the following article we’ll discuss what’s inside a wireless IP security camera and how it works, especially with the internet.

A wireless IP security camera differs from a typical digital video camera in several ways. First, a standard digital video security camera is connected to a processing and storage unit called a Digital Video Recorder or DVR. The camera is normally connected to the unit by running an RG-59 coaxial video transmission cable from each camera to the DVR. The camera transmits its video data over the cable to the DVR where it is compiled into a digital video file that is stored on a hard disk drive and may be viewed live on a digital camera security monitor at the same time.

On the other hand, a wireless IP security camera doesn’t use an RG-59 coaxial video transmission cable or any other video transmission cable. This camera has a built-in transmitter that sends its signal using IEEE802.11 or WiFi radio technology. The camera may or may not, depending on the type, also process the video data into a digital video file before being transmitted from the camera. In addition, when the signal leaves a wireless IP security camera it may be sent to an IP ready DVR over the internet, or it can be sent to any other receiving device (such as a computer or smartphone).

A wireless IP security camera also has its own built in web server technology. This allows one camera to capture video, create digital video files, and send them (using streaming technology) over the Internet to a variety of devices already mentioned. Accessing the camera is as easy as opening a standard web browser on your computer and entering the camera’s Internet address and a password. Even smartphones and similar devices such as iPhone, iPod Touch, iPad, Android, Symbian, and Windows mobile phones can remotely view and control the camera as well.

It’s important to note that a wireless IP security camera and an IP DVR system are different. The IP security camera makes a direct connection to the Internet via a wireless broadband modem or router. An IP DVR system on the other hand uses various wireless technologies to connect the cameras to the DVR FIRST. The DVR is than connected to the Internet via a variety of broadband Internet connections.

Note: For IP DVRs smartphones will require an application (app). For the iPhone and similar devices the application is available for free from the iPhone App Store on your phone. For all other types, Security Camera King offers the app for free when you download it from their website. As an additional note, please remember that the app only works with Security Camera Kings Elite Mini, Elite, and Ultimate DVRs with HDMI output. It will not work with any other type of DVR or any of Security Camera Kings DVRs.

Ultimately then, a wireless IP security camera can use the Internet to send digital video images to a variety of computers and smartphones or it can utilize the Internet as a network medium to connect several cameras to an IP ready DVR.

If you have any additional questions about a wireless IP security camera contact one of our security experts via “Live Chat” or telephone today.

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