Specifications for IP Cameras

Before purchasing your IP Cameras, it’s best to understand the specifications. IP Cameras have distinct advantages over the older analog cameras, but it’s not always easy to determine the right camera for each viewing situation. For example IP cameras are available with 640 x 480 (VGA) to 2592 X 1944 (5 megapixel) resolution. You certainly don’t need the 5 megapixel camera to view a doorway, so why pay for this extra performance. By reviewing your requirements and camera specifications you can match the camera to each viewing situation. New specifications have been added to the IP Cameras. Specifications to consider include the lens, resolution, light sensitivity, and dynamic range.

THE LENS:
There are a number of different types of lenses. There are fixed focal length, and variable focal length lenses. There are lenses with manual iris and others with auto-irises. Some lenses must be adjusted at the camera, and some new lenses can be adjusted remotely. Here are more details:

Fixed Focal Point Lens: These lenses view a fixed area and you can’t adjust the zoom. They are available with manual and auto iris control. For example the Axis M1101 is a simple indoor camera with a fixed 4.4 mm wide angle lens. It costs under $170

Variable Focal Length Lens: Also called variable lenses, allow you to adjust the field of view by adjusting the focal length setting. These are better lenses since they allow you to make adjustments so that you are viewing exactly what you want. They are available with manual or auto iris.

Iris Control: The iris can be controlled manually or automatically. While it is true that a smaller iris opening often means sharper images, too small an opening may blur an image due to an optical effect called diffraction. This problem can be seen in bright outdoor situations when a camera closes the iris too much and light is diffracted or spread over many pixels. The smaller each pixel is on an image sensor, the more of a problem diffraction becomes because the diffracted light affects more pixels. This can typically happen in cameras that use an automatic DC-iris lens in combination especially with megapixel sensors that have small pixels. (While a megapixel sensor has more pixels than a standard VGA 640x480 image sensor, the size of each pixel on a megapixel sensor is often smaller than the size of each pixel on a VGA image sensor.)

Manual Iris Lens: These lenses are usually used indoors and allow you to adjust the iris opening.

Auto-Iris Lens: The iris of the lens is adjusted by the camera. The iris opening is adjusted automatically when more or less light is required on the sensor of the camera. They are usually required for outdoor cameras. Some IP Cameras like the ones from IQinvision, do not rely on the iris but rather make all the adjustments electronically. The Axis P3343-VE is an example of an outdoor dome camera with an auto-iris lens. This is a very nice camera since the zoom and focus can also be remotely controlled. You can remotely control the view from your computer. It costs less than $1000.

P-iris lenses: P-Iris is a new type of iris control that is both automatic and precise. It works in conjunction with the camera to improve the quality of the video. Unlike a DC-iris lens, the main task of the P-Iris control is not to continuously adjust the flow of light through the lens. The primary objective of P-Iris is to improve image quality by enabling the optimal iris position to be set so that the central and best-performing part of the lens is used most of the time.

The P-Iris works with the electronics of the IP camera. It not only adjusts the iris, it also adjusts the gain (amplification of the signal level) and exposure time. This allows it to manage slight changes in lighting conditions and to further optimize an image. This allows the optimal iris position to be maintained as long as possible. In situations when the preferred iris position and the camera’s electronic processing capabilities cannot adequately correct the exposure, a P-Iris camera will automatically instruct the iris to move to a different position. In dark conditions, for example, the iris will fully open. In bright situations, a camera with P-Iris is programmed to limit the closing of the iris to a position that avoids diffraction or blurring, as explained earlier. Hence, in all lighting conditions, P-Iris can automatically make adjustments to deliver optimal image quality.

Take a look at the two pictures below. You can see the benefits of the p-lens.

Standard auto-iris


P-Iris Lens

At the moment only Axis and CBC have this new functionality. The Axis P1346 and P1347 are examples of cameras with p-iris lenses.

Megapixel Lens: Megapixel cameras require megapixel lenses. These lenses are much clearer than the standard CCTV analog camera lens. They cost more so if you see two megapixel cameras with the same number of pixels but one cost much less, they are probably using a less expensive (not as good) lens. Take a look at our article on how High-Resolution, Megapixel Cameras are not all Alike.

RESOLUTION
The latest IP cameras have the very nice capability of providing much better resolution than the old analog cameras. You can select cameras with 640 x 480 (VGA) lines to 2592 x 1944 pixels (5 megapixels). The resolution of the camera starts with the sensor, but also includes the lens and quality of the processor and compression used in the camera. Take a look at our article High Resolution Cameras are Not all Alike for more about this.

With a higher resolution you can see a wider view. Take a look at the picture below. It gives you some idea of the different views you can see.


To determine what resolution you need, you first consider how wide an area you would like to view and then what detail you need in that field of view. For example, suppose you want to view a doorway and you want to be able to identify a person’s face that comes in the door. In this case you only require a 640 x 480 resolution camera. On the other hand, suppose you want to be able to identify a license plate number in a parking lot that’s 60 ft wide. In this case you need a lot more pixels, and will require a 5 megapixel camera such as the Axis P1347 or IQ755.

COMPRESSION
There are 3 types of compression used by cameras, MJPEG, MPEG4 and H.264. There is some debate about what the best type of compression.

MJPEG requires the most data, provides a complete picture for each frame. Many people say this provides the best resolution.

MPEG4 reduces the amount of data required by only sending the video that change between frames. It improves the compression when there are small parts of the picture that are changing.



H.264 is a version of MPEG4 and provides the best compression. It adds a number of other compression algorithms that dramatically reduce the amount of data transferred. The chart below gives you some idea about the improvement provided by the different compression schemes.



Most new cameras from Axis, IQinvision, Sony and others now provide this compression scheme. This compression uses a lot of computer resources so some high resolution cameras can only handle lower frame rates. As an example, the Axis P1347 provides 5 megapixel resolution and up to 12 fps when using H.264 compression. It sells for under $1499. For more details about the latest compression take a look at our article.

LOW LIGHT AND AMPLIFICATION:
Camera light sensitivity is measured in lux, which is the amount of light reflected from the object being viewed. The lower the lux number the darker the view. For example, 0.27 lux is the amount of light from a full moon on a clear night, while 500 lux is the light in an office.

The low light performance of a camera is determined by:

· The size and sensitivity of the sensor
· The F-Stop and quality of the lens
· The quality of the video amplifier in the camera
· Day/night capability

Sensor: The larger the sensor the more light hits it, so the higher the light sensitivity.

Quality of the Lens (F-Stop): The F-stop and quality of the lens determines how much light gets through the lens. The smaller the F-number the more light gets in.

Amplifier and signal-to-noise: The quality of the amplifier in the camera determines the video performance when there is low light. As the light level goes down, the amplification increases. The signal-to-noise (S/N) of the amplifier becomes important at the lower light levels. When the light level is too low, electrical noise reduces the quality of the video. The better the amplifiers in the camera the less noise will be seen.


The Image on the left has more amplifier noise than the image on the right.

Day/night cameras can operate in greater range of light levels. When it gets dark the camera automatically removes the IR filter allowing more light to hit the sensor. At night the camera also changes to monochrome mode and improves the total light sensitivity of the system.

Cameras from IQinvision and Axis have good low light performance. For example the Axis P3343 and the IQeye IQ752 can operate in light levels as low as 0.05 lux. This means the cameras can see things even our eyes can’t see.

DYNAMIC RANGE
The dynamic range of a camera is a measure of the minimum and maximum light the camera can see in one frame. Wide dynamic range is helpful when you are looking at a person against a very bright background. Sony has introduced cameras with very wide dynamic range that allows you to see the image on the top.

CONCLUSION
As you can see it’s important to consider many of the camera specifications before selecting a camera. This assures you get the right camera at the right price. The type of lens, iris opening, resolution, compression, and dynamic range all need to be considered.

If you need help selecting the camera or lens, please give us a call at 914-944-3425 or send us a message. We are always there to help you get the right IP camera system.

Special IP Cameras for Special Situations

When IP cameras were introduced a few years ago there were very few choices. Today there‘s a wide selection from which to choose. They have really replaced the old analog camera systems. Now there are special IP camera systems that are designed for special situations. There are cameras that see in the dark, others that can see over a mile away, systems that are designed for cities, others that can work no matter where they are, and others that are covert and hidden so no one knows they are being recorded. This article reviews some of these specialized IP camera systems.

The Nite Track IP camera is a special PTZ camera that includes an IR illuminator. This system allows you to see in total darkness over 600 ft from the camera. It is a very effective covert camera system because people can’t see the IR illumination at night. The illuminator can be adjusted to see exactly the area you want to see. Take a look at the web page for more details.

If you need a system that can see over a mile away, there’s the special PTZ IP camera system that uses a focused laser IR illuminator. It’s matched with a high performance 60X optical zoom lens that adjusts from 12.5mm to 750 mm or with doubler adjusts from 25 mm to 1500mm. During the day this amazing camera allows you to recognize things that are 19,685 ft away (6,000 M). At night the special laser illuminator reaches out 4,921 ft (1,500M). There’s more on our web page.

When you need a camera system that can watch almost everywhere at once, take a look at the IPDeputyNVR system. This system mounts on a pole and includes up to two cameras. This rugged outdoor surveillance system includes everything you need to establish a vandal resistant neighborhood surveillance system. The system includes choice of cameras and a built in computer with NVR software that provides up to 1 TB of storage. You can select standard IP cameras, megapixel or PTZ cameras. All this is provided in a complete environmental enclosure with power distributor, surge protection, heater/blower and space for additional components. The system communicates with your network by WiFi wireless, direct Internet connection or even 3G/4G cell communication.

What happens when there’s no Internet connection? Well you can use a complete camera system that includes an NVR system all in a covert box. This box also includes battery backup so that it will operate even if someone cuts the power. The system looks like an electrical box. It has room for a number of different cameras that include the IQ752 camera. With this megapixel camera you get enough resolution to identify a person’s face in an area that’s about 48 ft wide. It can see even when there’s very little light, with sensitivity of less than 0.05 lux. The battery backup allows the system to operate for hours without power. The camera has a CF memory card slot so you can add on board storage that can record many hours of video. This complete solution allows you to place a camera in new locations that were historically not available by IP cameras systems.

There are many more special cameras available and more becoming available every day. Just contact us for the latest and greatest at 1-800-431-1658 or 914-944-3425 or use our contact form.

H.264 Compression

The latest IP cameras are using the new video compression H.264. We have had many questions about this new compression method so here’s an article that provides the information you will need to better understand this new technology.

H.264 is a new version of MPEG4 and it provides about twice as much compression as the older version. Apple has been using this standard for a number of years and it is now available in the latest IP Cameras. A number of manufacturers have begun to introduce this technology. Axis is in the lead at the moment, but other companies such as Sony, IQinvision and others are slowly introducing their new models as well.

This latest video compression standard, H.264 (also known as MPEG-4 Part 10/AVC for Advanced Video Coding), is becoming the video standard of choice.

Compression Concept
The intent of the H.264/AVC project was to create a standard capable of providing good video quality at substantially lower bit rates than previous standards (e.g. half or less the bit rate of MPEG-2, H.263, or MPEG-4 Part 2), without increasing the complexity of design so much that it would be impractical or excessively expensive to implement. An additional goal was to provide enough flexibility to allow the standard to be applied to a wide variety of applications on a wide variety of networks and systems, including low and high bit rates, low and high resolution video, broadcast, DVD storage, RTP/IP packet networks, and ITU-T multimedia telephony systems.

H.264 is an open, licensed standard that supports the most efficient video compression techniques available today. Without compromising image quality, an H.264 encoder can reduce the size of a digital video file by more than 80% compared with the Motion JPEG format and as much as 50% more than with the MPEG-4 Part 2 standard. This means that much less network bandwidth and storage space are required for a video file. Or seen another way, much higher video quality can be achieved for a given bit rate.

Jointly defined by standardization organizations in the telecommunications and IT industries, H.264 is expected to be more widely adopted than previous standards.Video compression is about reducing and removing redundant video data so that a digital video f ile can be effectively sent and stored. The process involves applying an algorithm to the source video to create a compressed file that is ready for transmission or storage. To play the compressed file, an inverse algorithm is applied to produce a video that shows virtually the same content as the original source video. The time it takes to compress, send, decompress and display a file is called latency. The more advanced the compression algorithm, the higher the latency, given the same processing power.

A pair of algorithms that works together is called a video codec (encoder/decoder). Video codecs that implement different standards are normally not compatible with each other; that is, video content that is compressed using one standard cannot be decompressed with a different standard. For instance, an MPEG-4 Part 2 decoder will not work with an H.264 encoder. This is simply because one algorithm cannot correctly decode the output from another algorithm but it is possible to implement many different algorithms in the same software or hardware, which would then enable multiple formats to be compressed. Different video compression standards utilize different methods of reducing data, and hence, results differ in bit rate, quality and latency.

The graph below provides a bit rate comparison, given the same level of image quality, among the following video standards: Motion JPEG, MPEG-4 Part 2 (no motion compensation), MPEG-4 Part 2 (with motion compensation) and H.264 (baseline profile).

Figure 1. An H.264 encoder generated up to 50% fewer bits per second for a sample video sequence than an MPEG-4 encoder with motion compensation. The H.264 encoder was at least three times more efficient than an MPEG-4 encoder with no motion compensation and at least six times more efficient than Motion JPEG.

Frames
Depending on the H.264 profile, different types of frames such as I-frames, P-frames and B-frames, may be used by an encoder.
An I-frame, or intra frame, is a self-contained frame that can be independently decoded without any reference to other images. The first image in a video sequence is always an I-frame. I-frames are needed as starting points for new viewers or resynchronization points if the transmitted bit stream is damaged. I-frames can be used to implement fast-forward, rewind and other random access functions. An encoder will automatically insert I-frames at regular intervals or on demand if new clients are expected to join in viewing a stream. The drawback of I-frames is that they consume much more bits, but on the other hand, they do not generate many artifacts.

A P-frame, which stands for predictive inter frame, makes references to parts of earlier I and/or P frame(s) to code the frame. P-frames usually require fewer bits than I-frames, but a drawback is that they are very sensitive to transmission errors because of the complex dependency on earlier P and I reference frames.

A B-frame, or bi-predictive inter frame, is a frame that makes references to both an earlier reference frame and a future frame.

Figure 2.
When a video decoder restores a video by decoding the bit stream frame by frame, decoding must always start with an I-frame. P-frames and B-frames, if used, must be decoded together with the reference frame(s).In the H.264 baseline profile, only I- and P-frames are used. This profile is ideal for network cameras and video encoders since low latency is achieved because B-frames are not used.

Basic Concepts of Reducing the Data
A variety of methods can be used to reduce video data, both within an image frame and between a series of frames.
Within an image frame, data can be reduced simply by removing unnecessary information, which will have an impact on the image resolution. MJPEG utilizes this algorithm.

In a series of frames, video data can be reduced by such methods as difference coding, which is used by MEPG4 and H.264. In difference coding, a frame is compared with a reference frame (i.e. earlier I- or P-frame) and only pixels that have changed with respect to the reference frame are coded. In this way, the number of pixel values that are coded and sent is reduced.

Figure 3. With Motion JPEG format, the three images in the above sequence are coded and sent as separate unique images (I-frames) with no dependencies on each other.

Figure 4. With difference coding (used in most video compression standards including H.264), only the first image (I-frame) is coded in its entirety. In the two following images (P-frames), references are made to the first picture for the static elements, i.e. the house, and only the moving parts, i.e. the running man, is coded using motion vectors, thus reducing the amount of information that is sent and stored.

The amount of encoding can be further reduced if detection and encoding of differences is based on blocks of pixels (macroblocks) rather than individual pixels; therefore, bigger areas are compared and only blocks that are significantly different are coded. The overhead associated with indicating the location of areas to be changed is also reduced.

Difference coding, however, would not significantly reduce data if there was a lot of motion in a video. Here, techniques such as block-based motion compensation can be used. Block-based motion compensation takes into account that much of what makes up a new frame in a video sequence can be found in an earlier frame, but perhaps in a different location. This technique divides a frame into a series of macroblocks. Block by block, a new frame—for instance, a P-frame—can be composed or ‘predicted’ by looking for a matching block in a reference frame. If a match is found, the encoder simply codes the position where the matching block is to be found in the reference frame. Coding the motion vector, as it is called, takes up fewer bits than if the actual content of a block were to be coded.

Figure 5. Illustration of block-based motion compensation

Improving Compression Even more with H.264
H.264 takes video compression technology to a new level. With H.264, a new and advanced intra prediction scheme is introduced for encoding I-frames. This scheme can greatly reduce the bit size of an I-frame and maintain a high quality by enabling the successive prediction of smaller blocks of pixels within each macroblock in a frame. This is done by trying to find matching pixels among the earlier-encoded pixels that border a new 4x4 pixel block to be intra-coded. By reusing pixel values that have already been encoded, the bit size can be drastically reduced. The new intraprediction is a key part of the H.264 technology that has proven to be very efficient. For comparison, if only I-frames were used in an H.264 stream, it would have a much smaller file size than a Motion JPEG stream, which uses only I-frames.

In this mode, four bottom pixels from the block above are copied vertically into part of an intra-coded macro-block.	In this mode, four right-most pixels from the block to the left are copied horizontally into part of an intra-coded macroblock.	In this mode, eight bottom pixels from the blocks above are copied diagonally into part of an intra-coded macro-block.

Figure 6. Illustrations of some of the modes that intra prediction can take in coding 4x4 pixels within one of the 16 blocks that make up a macroblock. Each of the 16 blocks in a macroblock may be coded using different modes.

Original source image Intra predicted image

Residual image Output image
Figure 7. The above images illustrate the efficiency of H.264’s intra prediction scheme, whereby the intra predicted image is sent for “free”. Only the residual content and the intra prediction modes need to be coded to produce the output image.

Block-based motion compensation—used in encoding P- and B-frames—has also been improved in H.264. An H.264 encoder can choose to search for matching blocks—down to sub-pixel accuracy—in a few or many areas of one or several reference frames. The block size and shape can also be adjusted to improve a match. In areas where no matching blocks can be found in a reference frame, intra-coded macroblocks are used. The high degree of flexibility in H.264’s block-based motion compensation pays off in crowded surveillance scenes where the quality can be maintained for demanding applications. Motion compensation is the most demanding aspect of a video encoder and the different ways and degrees with which it can be implemented by an H.264 encoder can have an impact on how efficiently video is compressed.

With H.264, typical blocky artifacts—seen in highly compressed video using Motion JPEG and MPEG standards other than H.264—can be reduced using an in-loop deblocking filter. This filter smoothes block edges using an adaptive strength to deliver an almost perfect decompressed video.

Figure 8. Blocky artifacts in the highly compressed image at left are reduced when a deblocking filter is applied, as seen in the image at right.

Conclusion
H.264 compression provides a significant improvement in video compression technology. It is supported by many different standards groups making it one of the most accepted standards. Because it provides a dramatic improvement in compression, it reduces the bandwidth and storage required. It provides an 80% improvement over MJPEG compression and about 50% improvement over MPEG4 compression. It is now available in the latest cameras from Axis, and other manufacturers.

Need more information about this compression or the cameras that utilize it, just contact us at 914-944-3425 or by using our contact form.

Access Control Technology Review

Door access control systems have changed over the years. The early units were quite difficult to install. They used simple card readers with all the intelligence located back at the control panel. Over the years more intelligent devices were developed, and now, in the state-of-the-art solutions, most of the intelligence is located at the reader near the door. The latest IP type readers make use of your Ethernet network and are very easy to install. This article reviews the types of systems available and how they can be integrated with IP cameras.

In physical security, the term access control refers to the practice of allowing entrance to a property, a building, or a room only to authorized persons. Physical access control can be achieved by a human (a guard, bouncer, or receptionist), through mechanical means such as locks and keys, or through technological means such as door access control systems that use magnetic locks. In general, in an automated system, access is controlled using a special RFID type proximity card or by keying in an ID number. If the system accepts the person, a relay is activated that unlocks the door.

HISTORICAL REVIEW

Basic non-intelligent Readers: The first automated door access control systems utilized simple non-intelligent reader panels that connected back to a central control panel. All the access requests were forwarded back to the central control panel.

Semi-intelligent Readers: The next generation of readers included some intelligence. These readers included enough intelligence to control the door lock hardware, but did not make any access control decisions. The reader simply passed on the code entered to the main controller and then waited for a response. These readers are usually connected to the main panel via an RS-485 bus.

Intelligent Readers: The first intelligent readers connected back to a centralized control panel via the same RS-485 connection as semi-intelligent readers. They included memory and enough intelligence to make access decisions independently of the control panel. The special control panel provides configuration updates and receives events from the readers and maintains a history of the door access.

Intelligent IP Reader and Controller: This is the latest type of reader (such as the reader from ISONAS). It’s similar to the intelligent reader in that all the decisions are made at the reader, but instead of using a specialized control panel, it uses a standard computer running access control software. It also uses the standard network infrastructure for communication (CAT 5 or 6 cable). Since it totally eliminates any special wiring and specialized control panels, it is the simplest to install and maintain.

IP DOOR ACCESS CONTROL

The latest door control systems use an IP reader and special software that runs in a Windows computer. The IP reader is attached to the Ethernet network. Magnetic locks and strikes secure the doors which are opened by the IP Reader when the right access card (or other RFID device) passes near the IP Reader. Each Reader contains a list of people who are allowed to enter the door. Software running in a Windows computer is used to control the system, add the people who are allowed to enter the door, send the list to the readers and provide reports of who and when people entered.

IP Reader
An IP based system, such as the one from ISONAS, utilizes the latest IP readers. It does not require a centralized control panel. Since this system uses network attached components and standard computer systems it provides a very flexible door control system. The reader is powered over Ethernet (PoE) so you don’t require any additional power wires. The reader includes door sense input connections and provides an output that controls the electric door lock.

These readers are designed for both indoor and outdoor use. The optional keypad can be used for additional personnel verification. There are models that use the HID format RFID proximity devices. The devices are available in many different formats from plastic cards, to keychain fobs.

Magnetic Locks and Strikes
There are a variety of automated door locking systems available. You can select either a magnetic lock or electric strike to secure a door.

Magnetic locks are used in high security areas where you need to monitor the movement of people. Since people are required to use their access cards in both directions, you can track who enters and leaves a secure area.

The locking system uses an electromagnetic and armature plate to secure the door. The electromagnet is attached to the door frame while the armature plate is attached to the door. A current passes through the electromagnetic so that it is magnetically attracted to the armature plate holding the door closed. The magnetic strength can provide over 1500 lbs. of holding force. Locks with higher magnetic force can be used to secure an outer door, while lower force locks can be used to secure inner doors.

The locks require special power supplies that can be integrated into a fire panel. It is important to assure that the locks can be released if an emergency situation occurs.

The electric strike are easy to install and are used to secure outer and inner doors, but do not prevent egress from an area like the magnetic lock. It replaces the fixed strike place in a standard lock. Like a fixed strike, it normally presents a ramped surface to the locking latch allowing the door to close and latch just like a fixed strike would. To exit from a secured area, the door can be opened by using a knob or level.

To simplify installation, it is important to use locks that require less than 500ma of current. This allows the reader to be powered over Ethernet. The electric locks from Rutherford Controls are examples of this type of low power lock.

Electric strikes generally come in two basic configurations:

• Fail-secure. Also called Fail-locked or non-fail safe. In this configuration, applying electrical current to the strike will cause it to open. In this configuration, the strike would remain locked in a power failure, but typically the knob can still be used to open the door from the inside for egress from the secure side. These units can be powered by AC which will cause the unit to "buzz", or DC power which will offer silent operation, except for a "click" while the unit releases.

• Fail-safe. Also called Fail-open. In this configuration, applying electrical current to the strike will cause it to lock. In this configuration, it operates the same as a magnetic lock would. If there is a power failure, the door would open merely by being pushed/pulled open. Fail safe units are always run using DC power.

ADDING THE IP CAMERA

Adding video to a door control system increases the overall security of the system. By viewing and recording the video, you can keep a visual record of all the people entering your facility as well as determining if the access tag matches the person. You can also catch multiple people entering with only one access (tailgating). Adding additional software will even allow you to do this automatically.

IP camera
By adding an IP camera you can view who enters and leaves an area. The video is captured at the computer running the special NVR software. Cameras from Axis, JVC, IQinvison and others can be used to capture the video.

Adding audio: By using an IP camera that supports audio you can even record the audio at the time of entry. There are many cameras that support audio but you must also select cameras that are also supported by the NVR software. Cameras from Axis and Sony are supported by a number of NVRs and are available with 2-way audio support.

Software
It is important to select access control and the video recording software that are compatible. For example, the Isonas Crystal Matrix software and OnSSI’s NetDVMS software work well together.

The IP reader system notifies the Crystal Matrix Software that a person has opened a door. The Crystal Matrix software then notifies the NetDVMS surveillance software that the door has been accessed causing the NVR software to record the video from the specific camera that is watching the door. Since the video is time stamped you can easily match video to the door access software timeline.

Adding additional Intelligence
There is also optional analytic software available (such as AgentVI) that can automatically watch for tailgating and provide alarms if more than one person tries to enter an area.

MANNED ACCESS CONTROL USING JUST AN IP CAMERA AND INTERCOM

As an alternative to an automated system, you can control access by just using an IP camera at each entry door. This works only if you have a centralized security person. Using a camera and intercom, the security person can talk to the person at the door, make a decision based on the picture he sees on his monitor, and then press a lock release button to open the remote door. All communication is done over your Ethernet network so it’s easy to implement.
Here’s what you need to implement the system:

Cameras with Audio
In almost all cases a camera that includes audio, supports MPEG4 compression. This form of compression includes data packets for audio transfer as well as video. For example, the Axis 210A includes two-way audio. It has audio input and audio output so you can attach a microphone and powered speaker. Other cameras with audio include Axis214PTZ and Axis211A.

The intercom and microphone are connected to inputs on the IP camera. All the information from the camera is sent over the standard Ethernet network back to a Windows type PC server.

Doorway Intercoms

To have a two-way conversation with someone at a doorway requires both a microphone and speaker. The microphone and the speaker must be compatible with the input and output requirements of the camera. It’s best to use a directional microphone to minimize any extra noise in the area. Here’s an example of a two way system that is compatible with most cameras.

AOP-SP-WS
Bi-directional Speakerphone. Surface Wall mount speakerphones are designed to interface with various modes of audio/video transmission systems. They provide bi-directional audio with the IP Network cameras that support audio, and video servers with audio support. It contains a built-in electret condenser microphone and a 4" speaker. Also control potentiometers for adjusting the sensitivity of both transmitted and received audio. It can be used outdoors but requires protection from direct exposure to the elements.

NVR IP Software
Special software that runs in your Windows PC computer is used to communicate with the intercom and allows you to view and record the video. For example, NetDVR and NetDVMS from OnSSI provide two-way audio support as well as recording both the video and audio.

These systems are easy to implement but I’m sure you will have questions about all the details. Just contact us at 914-944-3425 or use our contact form to get more information.

What's a Watt

Knowing more about voltage, current and power can help when you are putting together an IP camera system. This is especially true when you are selecting the power supply and running the wire. Computers, light bulbs and cameras have a power rating that is measured in Watts and sometimes in Volt-Amps (VA). Ever wonder what a Watt is, or why we sometimes use watts and other times Volt-Amps? It’s important to know about the power, because if you don’t have enough of it you’re in trouble. This article provides the information you need to stay out of trouble.

Current is the flow of electric charge. The unit of measure for current is the ampere, or abbreviated it’s “amp”. If you stick your finger in an outlet (please don’t do this), it’s the current that knocks you on your rear. The more current you have, the larger the size (or gauge) of the wire you need to carry the flow of the current. If the wire gauge is too small, it resists the flow of the current and it gets hot. (See the description of a resister below.)

Resistance is what generates the heat when voltage and current are applied to an electric circuit. An electric heater is an example of a resister. The more current that follows through a resister the hotter it will get. Resistance is measured in ohms.
Voltage and current are related in electrical equipment by Ohm’s law. Voltage (V) is related to current (I) by the resistance (R) of the electrical circuit. The formula is V=I X R. This means that if you run 2 amps of current through an IP camera that has a resistance of 6 ohms you will get 12 volts (2 X 6 = 12 volts).

Almost everything, including wire, has some resistance. The thicker the wire the less resistance it has to the flow of the current. It’s like having a larger size pipe for water. The thinner the wire gauge the more resistance the wire will have, and the lower the voltage will be at the end of the wire. Also, the longer the length of the wire the more resistance is added. When you have a long run of wire, you should use a larger gauge size wire (thicker) to reduce the resistance.

For those who need more details, here they are, otherwise just go to Voltage description below.
To illustrate the problem of wire resistance, I will use a slightly more complicated drawing. In this example I added the 2 ohm resister to represent the resistance of the wire. Now there is a total of 8 ohms in the circuit (6 + 2 = 8). Since there is now more resistance in the circuit, the amount of current changes and so does the amount of voltage available at the camera. The equation to calculate the current is: I = V/R. So now the current equals 12/8 or 1.5 amps. The camera that was getting 12 Volts before we added the resistance of the wire is now getting only 9 volts (I used the formula V=I X R for this. 1.5 A X 6 R = 9 volts.) This lower voltage could be a problem for the camera. There are some charts on the Internet such as the one at http://www.interfacebus.com/Copper_Wire_AWG_SIze.html. It describes the American Wire Gauge (AWG) for various gauges vs. the resistance of 1000ft of wire.

Voltage is the difference of potential between two points of an electrical circuit. The higher the potential the more volts you have. For example you can generate a lot of voltage by rubbing your feet on a carpet, and make quite a large spark when you touch a metal surface (or someone else).

Another example can be seen at museums that have scientific displays. Sometimes they have displays that show the effect of voltage. They let kids touch the surface of a large metal ball. When they touch it, their hair sticks out in all directions. This is called a Van der Graf generator (but you probably don’t need to know this). It generates a very large voltage on the surface of the metal ball, and the static electricity makes your hair stand on end.

Now for Watts:
Here’s the definition of a watt: the watt (symbol: W) is equal to one joule of energy per second (and about 745 watts equals 1 horsepower). It measures a rate of energy conversion. It was named after our old friend James Watt. Remember his work with the steam engine? If not, you’re not smarter than a fifth grader.

Here are some examples of the Watt. A human climbing a flight of stairs is doing work at a rate of about 200 watts. An automobile engine can produce mechanical energy at a rate of 25,000 watts (which is equal to approximately 33.5 horsepower) while cruising. A household incandescent light bulb uses electrical energy at a rate of 25 to 100 watts, while compact fluorescent lights typically consume 5 to 30 watts. We also have Kilowatts (1,000 watts), Megawatts (1,000,000 watts) and if you have a power station available Gigawatts (too many zeros (9 actually)).

First off, you may know this, but there are two different types of electrical systems. There is Direct Current (DC) systems and Alternating Current (AC) systems. I’m going to start by explaining DC systems which are simpler than AC systems.

The Watt is related to the voltage and current. The formula for calculating the watt is: Watts (W) equal Current (I) X Voltage (V) or W = I x V. For example if I have a camera that requires 12 V DC and it takes 2 amps, it will require a power supply that can provide at least 24 watts. (2 x 12 = 24).

Volt-Amps or Power in an Alternating Current System
Power is fairly simple, when you are using a DC power supply. It gets a little more complicated when you use an AC power supply. In the alternating current world the voltage cycles up and down. This is called a sine wave. The voltage goes positive and then negative and back again. The current goes back and forth as well. These two cycles can be affected by the load, especially when the load includes other components such as a transformer or motor. Pan tilt cameras with motors are an example of a complex load.

When there is a complex load, the sine wave for the voltage can get displaced from the sine wave for the current and this changes the real power we will need. When we compute power in an AC network we use Volt-Amps instead of Watts.
We use the Power Factor to adjust for this variable power load. Now the Volt-amps equal the watts divided by power factor. The power factor is a number between 0 and 1 and its value is determined by the properties of the load. So if you have a system that needs 20 watt but there is a power factor of 0.5, the Volt-Amp required is 20 / 0.5 = 40 watts. Notice that the unit of measure is the same (further confusing things).

If you have a camera or other device that doesn’t have a complex load then the power factor equals “1”. This is true in most fixed IP cameras. In this case, Watts equals Volt-Amps.

In summary, current, resistance and power are important specifications to consider when installing IP cameras or any type of camera system. The gauge (thickness) and length of wire is important because it can affect the voltage. Power is measured in Watts, but it can also be the same as Volt-Amps, it’s just determined by the type of load (or camera) that’s used.

If you would like more information about how voltage, current and power affect your IP camera system, just contact us at 914-944-3425 or use our contact form.

What is Bandwidth and How Much is Required

Ever wonder why it takes so long to get a picture loaded on your computer screen? Do you sometimes have problems using your new cable telephone or VoIP system? What bandwidth is required for your Internet connection? Do you need 512 Kbits/sec or 20 Mbits/sec? This article provides the information you need to determine the best service and will help you correct problems you may encounter with your Internet connection.

We receive information in a number of ways. For example, we can listen to the radio, watch TV, talk on the telephone or use our computers to reach the Internet. In general we are receiving information in two distinct ways. In one case we are listening to the same information that is broadcast to everyone, and in the other case we are receiving a private message. No matter how we receive the information it is important that the message is loud and clear. Let’s take a look at some of the factors that affect the quality of what we receive.

Broadcast versus Addressed Information

First let’s understand the difference between receiving the information that’s broadcast versus getting information that’s addressed to us. The reason I’m reviewing the two types of communication is because it is helpful to know this when you are talking to your network provider. Some of these providers actually don’t understand this concept, so you have to help them along, especially when you are trying to explain a problem you’re having with their service.

When information is broadcast electronically, it is like a water pipe filled with fish. The pipe goes from one house to another and at each house there is a window in the pipe through which you can see the fish swimming. Since people are all looking at the same fish (information), you just need to have enough water pressure for the water to reach all the houses in the neighborhood. No one is taking any of the fish away. Cable television broadcasts TV signals so that everyone sees the same information (the fish) at the same time. Cable companies monitor the quality of the signal reaching each location to assure you get a good quality TV signal.

Sending information that’s addressed to specific computers is like delivering the fish to each person’s house. When you connect your computer to the Internet you get some data (fish) that’s addressed just to you. Each house takes some of the fish away so you need lots of fish. IP addresses are used on the network to address each of the computers and to assure that the information gets to the right place. Telephones are another example of addressed information. You call a specific house by using a specific phone number. Internet providers that focus on good data service should not only be interested in the quality of the signal, but also the bandwidth (amount of fish) that each user receives.

Data rate (or do we have enough fish).

The data or bit rate is related to the bandwidth available and it is a measure of the amount of information (number of fish) that can be sent over any transmission media. The data is sent over a transmission media that can be a cable wire, an optical fibre wire, or wirelessly using a radio. No matter what the transmission media, we are always concerned about the data rate.

If many people are trying to get the fish at the same time, you have a fish delay because you don’t have enough fish to go around. For example if the Internet provider tells you that you have a 10 Mbits/sec connection, you may not receive this data rate all the time. The problem is that the network is shared by many people so sometimes the bandwidth that you receive is reduced and you end up waiting a long time for a picture to load on your web browser. It’s far worse when you are talking to someone on the telephone, and there are missing sounds or interruptions to the voice.

When you have these problems it’s time to talk to your provider about the bandwidth they are actually providing.

How High a Data Rate Do We Really Need?

The data rate you need depends on what information you want to send. When you send real-time audio or video data it’s very important to receive a continuous flow of information. For example if you want to transfer video on the Internet, the data rate required will be determined by the resolution of the picture, the frame rate (or how many pictures you want to send per second), and the compression scheme you use. If you send video with a resolution of 640 x 480, it uses about 300 Kbits/picture when using MJPEG compression. If I want to send 10 pictures or frames per second, then I will need a data rate or bandwidth of 10 frames/second x 300 Kbits = 3000 K bits/second. This is the same as 3 Mbits/sec. So if we want to see the video at 10 frames/sec, we will require a bandwidth of at least 3 Mbits/sec.

Many DSL, cable companies and Verizon FIOS have one data rate for incoming (download) data rate and another for the outgoing (upload) data rate. Usually you would like a higher download rate, but sometimes, especially if you are viewing a camera, you would like a higher upload rate.

Now that you understand the concept of data rates, you will be better able to make the right choices for your Internet connection. These same concepts also apply to your local area network and even your wireless network.

If you need more help determining bandwidth (how many fish) you need, just give us a call at 914-944-3425 or use the contact form to send us a message.

Video Recording for IP Cameras

The Changing Technology of Video Recording
Pros and Cons of the latest IP Camera Recording systems
by Bob Mesnik

Recording video from surveillance cameras has changed over the years. First there were Video Cassette Recorders (VCR’s) and then Digital Video Recorders (DVRs) and now there are Network Video Recorders (NVR). VCRs were around for many years and have been replaced by DVRs that use hard drives. Now, NVRs that support the latest network attached IP cameras, are starting to replace the DVR. This article reviews the technology and how it has evolved over the last few years.

Video Recorder
Early video tape recorders were introduced in the 1950’s. In the 1960’s Sony introduced the first videocassette units (U-matic) which lead to the Beta and VHS VCR products. In the 1970’s the VCR started to be used in the surveillance market.

Video Cassette Recorders (VCRs) used in surveillance, are modified consumer VCRs that have one or more camera inputs to record video from CCTV analog cameras. Duration of storage is usually only up to ten days, depending on resolution and frame rate. These systems were simple to use and relatively inexpensive. Prices ranged from $200 to $1,000.

The downside was the difficulty in finding a specific videotape and then a specific time period. Tape is not too reliable, so even if you find the right tape you may find the video has deteriorated.

Digital Video Recorder
Around 2000, the DVR was introduced for surveillance applications. The Digital Video Recorder (DVR) converts analog video (from CCTV cameras) to digital data and records the data on computer type hard drives. 4 to 16 analog cameras can be attached to a DVR. These systems provide far more storage than tape, are more reliable and provide almost instant access to the stored video. Prices range from $500 to over $2500 (for up to 16 cameras).

Since the video is stored in a form that’s more compatible with computers, the video can be processed and distributed easily. DVR systems incorporate better video compression, and provide motion detection and alarms. Many DVRs have network connections. Data can be sent over the network and viewed on a PC or it can be stored on CD or DVD-Recordable discs.

The upside is the ability to attach a variety of analog cameras into the network. The downside is that the DVR system has a fixed amount of storage and is not easily expanded.

Network Video Recorders (NVRs)
The NVR or IP software is a major advance over the VCR and DVR. The introduction of network attached IP cameras around 1996 required a new type of recording system to be developed. Instead of using coax cable to distribute the video, the video is digitized and compressed in the camera and attached directly to the Ethernet network. The digitized video is now distributed over the network just like any other computer data. A number of software and hardware products were developed to support these new IP cameras. The software runs on standard computers connected to the same Ethernet network as the IP cameras. The software transformed the standard computer into a Network Video Recorder. Now many hundreds of IP cameras can be supported by this IP NVR software. Prices range from $500 to well over $25,000 (for hundreds of cameras).

Some manufacturers also introduced NVR systems that included a computer. The purpose of this system was to make the transition from analog CCTV technology to the new network attached IP technology as easy as possible for the video dealers. For example, instead of using a 16-channel DVR you could now get a 16-channel NVR.

The NVR systems are much more flexible and expandable than DVR systems. The Ethernet network can support a very large number of IP Cameras and the more advanced NVR software is designed to use multiple computers to support an almost unlimited number of cameras.

Most NVR software runs on a Windows type PC system. An IP camera system consists of the IP cameras, computer with hard drives and IP or NVR software. The computer performance and hard drive capacity depends on the number of cameras, the resolution of the video, the frame rate of the cameras as well as how long you want to store the video.

NVR software can be scaled to the requirements of the surveillance system. You can get low cost camera systems that support up to 25 cameras, medium level solutions that support up to 64 cameras and enterprise solutions that support hundreds of cameras.

Software Overview:
There are a number of software options such as NUUO, ProSightSMB, NetDVR and NetDVMS from OnSSI and a number of versions from Milestone (which are similar to the OnSSI software).

The software uses your own computer and it will allow you to view, store and retrieve video and control the cameras. There are a number of common capabilities and each package also has some unique features and functions. For example, all versions allow you to view the video using a web browser from anywhere on the Internet, store video only when motion is detected, and notify you of motion alarm by email or by an alarm sound on the PC. NetDVR and NetDVMS are more robust server/client type software and add among other things the ability to patrol through preset PTZ positions and to transfer the video to alternative storage on the network.

The software is licensed according to the number of cameras you are supporting. ProSightSMB and NetDVR are both licensed by groups of cameras 4, 9, 16 25, 36 64 cameras while NetDVMS is licensed with a base license plus a per camera license. Here are examples of each type of software license:

NUUO is an entry level software for small numbers of cameras. It runs as an application (rather than a service) so should be used with care in commercial surveillance applications. It is licensed for 4, 8, 12 and 16 cameras.

The following software solutions from OnSSI can run either as an application or a Service.

ProsightSMB is entry level software that supports a maximum of 25 cameras. It is a single site and single server type product. This is a small-scale video management system that provides live video, recording, playback and camera management and control. It allows viewing of cameras from any computer using a web browser.

NetDVR is a mid-range product that supports up to 64 cameras on one server, and operates as a server/client. It includes features such as NetGuard client software for viewing up to 64 cameras at a time on any workstation on the network, auto-patrol mode for PTZ cameras, stores audio and allows video to be off-loaded to additional storage on the network. It includes NetMatrix that pops video up on any designated PC monitor whenever there is an alarm condition.

NetDVMS is an Enterprise product that supports hundreds of cameras. It is licensed with a base license plus a per camera license. Besides having all the features of NetDVR, this software can run on multiple servers that are distributed over many sites. It includes NetMatrix that pops video up on any designated PC monitor whenever there is an alarm condition, and Net-PDA software that allows a user to view and control cameras from their PDA.

Advanced content analytic software can be added that counts people in an area or detects if a package has been left unattended at an airport. The bottom line is that more protection can be provided by these complex systems using much less human resources.

If you would like more information please contact us at 1-800-431-1658 or 914-944-3425 or send a message.