Posts Tagged ‘ hard disk drive’



Digital Security Cameras

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Friday, September 2nd, 2011

Almost all the security cameras these days are digital security cameras.  Compared to their old analog equivalents, they are lighter, more efficient, use less electricity, and just about anyone can install them.

Digital security cameras are a small-package of technological wonders from the lens to the video transmission type it uses.  In addition, digital security cameras get to “piggy back” on the personal computer industry; that is many times a device is advanced technologically for a computer; the digital security camera industry can reap the benefit of the advance as well.

In the following article, we’ll give you a brief overview of how a digital security camera actually works.  This should give you a better working knowledge so if you are considering a purchase you can make a wise one.

The digital security camera starts with a highly refined lens.   The lens has the responsibility of gathering the light reflected off objects in its field of vision and transferring the light images (with great detail), and small enough to be focused on a 1/4 inch square sensor chip.  The sensor chip is sensitive to light and emits tiny electrical impulse when exposed to light.

One of two different kinds of sensor chip is used in digital security cameras.  The Charged Coupled Device or CCD and the Complementary Metal Oxide Semiconductor or CMOS.   Although they go about it in different ways, the both produce the same end result; that is, electrical impulses that can be used to create a digital video image.

The digital security camera is actually nothing more than a very fast photographic camera.  It takes pictures at the rate of up to 30 pictures (called “frames) per second or denoted as 30 fps.  Playing back these pictures at the same speed they were taken gives the human brain the illusion that they are watching animation.  Actually, depending on many factors, rates as low as 15 fps can produce fluid animated video.

After each “picture” is taken that data is hurried along to an Integrated Circuit (IC) chip that is designed to correct for imbalances in many features of electronic video such as brightness, hue, color saturation, etc.  These specialized IC chips are called Digital Signal Processors or DSPs.  In addition up to this point the signals have actually been analog signals and it is here that they are converted into binary or digital form.

Once the cameras signals have been processed and digitized, they must be sent to the DVR for further action.  This is usually done via a video transmission cable, RG59 for example.

The DVR has many responsibilities including receiving the video transmission, saving it on a Hard Disk Drive or other non-volatile storage medium, and broad casting the signal to the Internet (if so desired) or a local monitor for live monitoring.

Don’t underestimate the power of the DVR and digital security cameras.  The DVR has a lot of simultaneous work that must be done.  Consider this; the digital security camera takes 30 pictures a second.  Let’s say for medium to high quality each picture taken ends up being about 1 MB in size.  Multiply that megabyte by 30 (the number taken in one second) now multiply that number by 60 (the number of seconds in a minute), and finally by 60, the number of minutes in one hour.   That means that an hour of security video imagery would be approximately 108,000 megabytes or 108 gigabytes!

To maintain quality but reduce the size of the video file, the DVR uses a CODEC utility which shrinks the size of the file but maintains as much quality as possible while doing this.   All of Security Camera King’s DVRs utilize the latest most efficient CODEC called H.264

So, as you can see there is a lot of work that goes on behind the scenes when using digital security cameras.  But even so, the versatility, price, application, functionality, and overall quality of the digital security camera is still much farther ahead that it’s older counterpart, the analog security camera.

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Color Security System

Written By:
Friday, February 4th, 2011

Color Security SystemA digital video color security system is a video camera based protection and monitoring component system. Although a bear-bones system may only require two separate devices to operate, it normally consists of three or more. At a minimum a color security system requires at least one camera and a Digital Video Recorder or DVR. However, if you want to be able to watch what your system is recording, you will also want to use the third component, a color monitor.

The “work flow” of a color security system begins with, and is really based on, the digital video color security camera. A color security system may have only one camera, or it can consist of as many as sixteen when the system utilizes one DVR. The camera or cameras send their color video data to the DVR unit which contains an on-board computer processor designed specifically to do work with color video data and coordinate the color security system functions. Once the processor has interpreted the digital data from the camera, it compiles the data into a digital video file which can be viewed live if a monitor accompanies the system and/or saved for later use on the DVR hard disk drive.

The digital video camera in a color security system records digital images by converting light energy into electrical energy. It does this using one of two different sensors that create measurable electronic charges when light strikes their photosites. The sensors are known as Charged Coupled Devices or CCDs or Complimentary Metal Oxide Semiconductors or CMOSs.

These sensors have tremendously small diodes in an incredibly small amount of area. Most color security system cameras’ sensor chips are less than 1/2 inch square in size. The lens focuses the light image on this small area, which on a typical 1/2 inch CCD can contain 300,000 to 500,000 photosites. The sensors’ photosites are usually designated to detect red, green, or blue light. This configuration is often called a Bayer filter. When the data from all of the red, green, and blue sensing diodes or photosites is compiled it creates a high quality electronic color image.

The color security system further processes the electronic image by passing it through an on-board circuit chip called an analog-to-digital converter. This converts the electronic analog signals into binary or digital data that is then transmitted in a variety of ways, one of the most common being along an RG-59 coaxial video transmission cable. (Signals can also be sent wirelessly via radio waves).

The other end of the cable is connected to the DVR unit. The data from the color security system camera is still unrefined and it is the responsibility of the DVR unit with its accompanying Digital Signal Processor or DSP to add the finishing touches. It does this by using a utility, either in software form or contained in an on-board microchip, that reduces the size of the otherwise incredibly large digital video file without sacrificing a significant amount of quality.

Digital video, like cinematography, actually consists of several photographs (digital-based in this case) that are taken in a very short period of time. The human eye and brain are slow enough to fool into thinking they are seeing fluid, motion video if the photographs pass by quick enough. The number of photographs taken in one second is usually called the “frame rate” and is designated as “frames per second” or fps and is typically around 29 fps.

Consider the file size of a typical high quality digital camera. Now multiply that size times 29 and you have the size of the digital file for one second. Multiply that times 60 seconds, and again times 60 minutes, and the result for one hour of video at that rate is 104,400 times the size of one digital photograph. You can appreciate how large the file size can be.

Every color security system uses a form of the utility mentioned above. One of the most recent and efficient COmpression/DECompression or CODEC utilities is the H.264. Using the CODEC makes the files much easier to handle and increases maximum storage capacity of the DVR.

Security Camera King features several different color security systems including our Elite Mini, Elite, and Ultimate DVRs. We’ve designed our color security systems to give you the freedom to change components to make the system fit your specific needs. Contact one of our security experts today for more information.

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Security Flood Light DVR Camera

Written By:
Thursday, January 20th, 2011

Nothing says “”Gotchya!” to a potential intruder, vandal, or burglar better than a security flood light DVR camera. Thanks to modern technological improvements these devices are an entire compact digital video security system. They can be used in both residential and commercial applications and can be extremely effective when placed in the proper location.

Not only does a security flood light DVR camera help to protect and prevent perpetrators from causing damage or breaking and entering, but it also offers positive deterrence. It’s already been proven by the law enforcement agencies in London, England and New York City that the mere presence of digital video cameras deters criminal activity.

However, the security flood light DVR camera takes it one step further. Not only does it record still digital photographs or digital video images of the intruder, but once the unit senses motion, it snaps on a powerful high wattage flood light illuminating the surrounding area and “spotlighting” the intruder as well.

In addition to protecting homes and businesses, these units are great for protecting other property as well. Boat docks with electricity, barns, storage areas, specific portions of land, back entrances of retail stores, and no-trespassing industrial areas as well can benefit from the protection of a security flood light DVR camera.

The units are relatively easy to install and use as well. Basically, all that is required for installation is to mount the unit, connect it to a standard residential type power line, and select the settings you desire. Then walk away and be confident that your security flood light DVR camera will protect you and/or your family, business, or property.

Before we provide some detail about the design and function of a standard security flood light DVR camera, let’s briefly describe a typical digital video security camera system and how it works.

Most standard digital video security camera systems contain one to several cameras, a Digital Video Recorder or DVR, and perhaps a monitor. The cameras are mounted in various strategic locations and send their digital video data to the DVR unit by means of a digital video cable run from each camera to the unit, or wirelessly using radio signal transmitters and receivers.

The DVR unit, much like a highly specialized personal computer, contains a hard disk drive like those found in computers. The DVR unit processes the digital data and creates a digital video file that can be viewed live on a monitor and/or saved on the DVR for later use.

A security flood light DVR camera is basically a miniature version of the basic system without the monitor. The unit contains all the devices (sans the monitor) within one relatively small, compact fixture. The floodlight is usually a powerful 500 watt halogen flood lamp. These lights can project a powerful beam of light in a relatively wide field of vision.

Connected to the light, DVR, and the camera is an infrared motion detector. The motion detector, known as a PIR or Passive InfraRed sensor, can detect the infrared radiation emitted by the objects in its field of vision. When this “heat signature” changes greatly or rapidly, the sensor interprets this as motion. The sensor activates a relay that switches the security flood light, DVR, and camera on. Depending on the model, the entire unit switches off either after motion is no longer detected or specified time period after the initial “On” state.

When the camera is switched “on” it immediately begins capturing digital video images (or stills), with the flood light helping to provide a crisp, clear, bright picture. An on board processing chip saves the data either as digital photographs or digital video files to the DVR.

The DVR in this case is not a large hard disk drive, but usually consists of an SD card (Secured Digital card), a compact flash card, thumb drive or similar mini-portable memory device. All the user needs to do is remove the SD card, transfer the files to their personal computer and view, print, or make movies disks of the saved data.

Although a security flood light DVR camera cannot provide the extensive precise coverage of a full size standard digital video security system, it does offer an economical alternative and can be quite useful for specific situations. Contact our security experts via Live Chat or telephone if you have any addition questions or would like to make a purchase.

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Wireless PC Compatible Security Camera

Written By:
Thursday, January 6th, 2011

Nothing can offer you the peace of mind in security and the power and flexibility of application and use like a wireless PC compatible security camera. Thanks to modern electronic technology advancements and the growth of internet applications, a wireless PC compatible security camera is also reasonably priced to be affordable for just about any budget.

What exactly is a wireless PC compatible security camera and how does it work? We’ll attempt to answer these questions in the following article in order to give you a better understanding of the device and help you to decide if it is right for your security and monitoring application.

Before we talk about a wireless PC compatible security camera, let’s describe a basic standalone system first. A standard digital video security camera system usually consists of one or more digital video cameras, a Digital Video Recorder or DVR, and a monitor. The digital video cameras are connected to the DVR by a video transmission cable, usually RG-59 coaxial cable. A cable must be run from each camera to the DVR unit.

The camera(s) captures light images and converts them into electronic video images. It also converts the data created for this into digital or binary form using an on-board analog-to-digital processing chip. The digital data is sent to the DVR where a Digital Signal Processor or DSP, a highly specialized computer processor dedicated to making videos, uses the data to create a digital video file. The digital video file can be viewed in real-time (live) and/or saved on the DVR’s hard disk drive for later viewing, copying, etc.

A wireless PC compatible security camera captures the image and creates the digital video image in the same manner. However, it differs by transmitting the initial digital data from the camera wirelessly and by storing the data on a PC’s hard disk drive. Basically it eliminates the use of a standalone DVR and processor unit as well as a separate monitor. This has advantages and disadvantages that we will discuss later.

Most wireless PC compatible security cameras are their own little system. The camera captures the image, transfers it into digital form, creates a type of digital video file and then sends it via an on-board transmitter to a corresponding wireless internet connection such as a wireless router or wireless modem. The camera unit usually has its own IP address that identifies it on the Internet.

Using a common Internet browser, the user can access the secure camera with a username and password, and monitor as well as control some functions remotely from any personal computer, Mac computer, Apple iPhone, iPad, iPod Touch and even 3G and 4G smartphones. Some cameras have the ability to move horizontally and/or vertically to increase the range of the camera’s field of vision and may be able to enlarge objects in the field of vision. These cameras called Pan-Tilt-Zoom or PTZ cameras can be controlled remotely from a computer Internet browser as well.

These cameras normally use MPEG4 or MJPEG video compression to reduce the size of the digital video file to make it easier to send via the internet. Generally, you need not be an IT professional to install and operate these cameras. All you need to do for most wireless PC compatible security cameras is mount the camera and install some software from a CD onto your computer or download an application (app) to your smart phone and your ready to go.

These systems use the PC to replace the standalone DVR unit and monitor. If the user wants to record the video files for archiving or later viewing they can normally save them on their computer’s hard drive. If they choose to view them live, they can watch them on the computer’s monitor using most common internet browsers such as Internet Explorer, Firefox, etc.

As mentioned earlier, there are advantages and disadvantages to using wireless PC compatible security camera systems instead of standalone systems. Probably the greatest single advantage is lower cost due to the fact that a standalone DVR or monitor is not required as an existing personal computer can be used instead. Also, since the Internet is the medium for distributing the final video file, the cameras can be remotely accessed from anywhere in the world there is broadband internet access.

There are disadvantages. The system could be prone to computer viruses, Internet bog downs, and using so much of your personal computer’s resources that it effects the computer’s performance for doing other tasks.

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