The two typical video compression formats for DVRs before H.264 were Motion JPEG, or M-JPEG (Joint Photographic Experts Group), and MPEG-4 (Moving Picture Experts Group).  These three compression modes can all display and record up to 30 FPS.  However, there are some areas in which they differ significantly.

M-JPEG

M-JPEG is the compilation of separately compressed JPEGs in a sequence, thus creating a video.  It focuses on the quality of the image, rather than the quantity, i.e. less frames per second, and priority is given to image resolution.  This compression is appropriate for megapixel cameras, and many cameras are supported.

Some advantages of M-JPEG include better decompression on the computer, better live viewing, and great image quality (consistently).  M-JPEG is also unlicensed, making it free for the user and viewer.  Another aspect that makes M-JPEG good is its robustness, if one frame is dropped, then it does not affect the video.

The disadvantages of M-JPEG are huge drawbacks, however.  Sound synchronization is not supported.  Due to the high resolution of the images, they take up a lot of space on the HDD, although the image size can be restricted in the settings.  Also because of the size, it requires much more bandwidth to transmit the photos.

MPEG-4

MPEG-4 uses techniques similar to M-JPEG, as far as putting pictures in a sequence.  It essentially compares two compressed images, saves the picture, and it saves only the difference from each additional sequential image, such as movement, thus saving time, memory space and processing power.

A higher compression rate is amongst the advantages of MPEG-4.  It can sync audio and video, and is great for real-time viewing.  MPEG-4 was designed to support low-bandwidth applications.

Disadvantages of MPEG-4 include lower picture quality (than M-JPEG), and it is licensed, making a fee a possibility for viewers.  It supports a less number of cameras, such as megapixel cameras.

H.264

H.264 is another name given to MPEG-4 Part 10, and is also known as AVC (Advanced Video Coding).  Like MPEG-4, H.264 saves the picture and uses the background for the next few frames, and just records the movement, but with more flexibility.  It compresses the images and reduces the space it takes on the HDD, while preserving the crispness and quality of the image.

H.264 offers higher compression rates, and requires much less storage space than MPEG-4 and M-JPEG.  It supports AV syncing and it is designed for real-time videos.

Some cons of H.264 are low robustness, i.e. if a frame drops because of bandwidth, then the video is affected.  Decompression is a bit high on computers, and live viewing is somewhat delayed.

This is our front office, the left being the original image, the center is MPEG4, and the image on the right is H.264.  Notice how it’s there is not much difference in the picture quality, in fact, they’re very similar.  What’s important is the compression, the space you can save by using each video codec.  These pictures were taken with a GeoVision computer-based DVR.

Video Compression Comparison (left: original; center: MPEG4; right: H.264)

Here is a chart portraying the difference in space each compression takes. (image from Axis)

H.264 Video Compression Comparison Line Chart

This is a post from: 2M CCTV, an online cctv cameras retailer.

Rick Charney

ABOUT THE AUTHOR

Rick Charney is the current manager of Stealth Monitoring, a live surveillance monitoring provider for corporations and other large businesses.

Copper Pipes

This is a post from: 2M CCTV, an online cctv cameras retailer.

Todd Thompson

Todd Thompson - Construction Manager – 2M CCTV

Follow Todd on Twitter

Among the reasonably priced cameras on the market, even the best ones may not capture video footage that will help you solve every crime.

Whether it is the lighting or very fast motion “like a speeding car” unless a surveillance camera is outfitted with the best lens and top-of-the-line features, it can be difficult to produce evidence in a trial that will be conclusive enough to satisfy a jury.

Technologically, however, the enhancement of video footage and audio recording has advanced to the point at which evidence can be rendered indisputable, thus providing clear court decisions and fewer unsolved cases when video is entered as evidence.

Doug Carner is the president and lead technologist for Forensic Protection, where they can actually “de-blur” captured video.

Before

After

Here is what they do in a nutshell…

Surveillance companies are working on incorporating technology that is only available in forensic labs and video enhancement service providers.  The process is called de-blurring, and it is very useful if the camera was moved around a lot while taking the video.

The process is a bit tedious.  First, the horizontal and vertical paths of the each frame are integrated together, otherwise known as a kernel.  Then to reverse the blurriness, an algorithm must be applied, and may take several hours to inverse one minute of video.  Researchers are developing new algorithms that approximate frames to accelerate the method.

The moving object’s motion path is then determined and each object is then isolated and assigned its own motion kernel corrections.  From this point onward, it becomes simple.Traditional enhancement steps like pixilation suppression, focus correction, video stabilization and pixel fusion can be successfully applied.  If this is then followed by cropping, enlargement and lighting corrections, the results can be stunning.

You can read the full article at http://www.forensicprotection.com/deblur_science.html

This is a post from: 2M CCTV, an online cctv cameras retailer.

Chris Mozingo

Christopher Mozingo - Sales – 2M CCTV

877-926-2288 x 6021

When it comes to recording overnight, there are several ways that cameras can do this.  Infrared is essential when recording overnight.  Day/Night recording is available on dome, fixed dome, bullet, box, and PTZ cameras.

The camera can be a true day/night (TDN) with a mechanical IR cut filter (ICR), digital day/night, which adjusts electronically without a filter, or it can have IR LEDs (light emitting diodes).  Some cameras have IR LEDs surrounding the lens to provide illumination.  Black and white cameras can also record in low light settings.

True Day/Night Cameras

During the day, infrared wavelengths are transmitted to the camera, and without a filter, can be construed as a color modification, reducing the image clarity.

Most true day/night (TDN) cameras, however, have a mechanical (ICR) infrared cut filter removable (Note: The industry jargon is usually “IR cut”). When the filter is put in place, it filters the wavelengths, improving the quality of the image by showing only the “visible” light, removing the “infrared” light from the spectrum.

Day/Night Camera IR Cut Filter Turns Off When It Gets Dark

When the camera senses low lighting, it automatically removes the filter that intercepts the infrared waves.  When the filter is removed, the camera starts recording in black and white.  Without color, there is no need for the IR cut filter.  The IR waves cannot be seen by the human eye, but advanced cameras can catch the infrared waves reflecting off objects.

True day/night cameras offer top performance in both day and night situations. The Veilux SVS-60CDNRD is a great example of a TDN.

Day/Night Cameras (Digital)

Digital day/night cameras allow for viewing in both day and night conditions, without the use of a IR cut filter.  During the day it records in color, adjusting electronically to offer similar benefits to TDN, but with a slightly lower cost.  Once it becomes dark, the camera digitally switches to black and white.

When the camera switches to black and white, it solely depends on the lighting and infrared waves reflecting off objects to capture the image.

The best way to see how digital day/night cameras perform is to check their LUX rating.  The LUX rating determines how much light is needed for the cam to see at night.  There are quite a few cameras available that only need a minimal amount of light to see at night.

For some cameras the ambience from the star lit sky is enough to attain a nice image at night.  When choosing a camera, be sure to check out the specification sheet and check what LUX the camera operates at.  Here’s an article where we mention LUX and the other important elements to look for in a spec sheet.

Cameras with IR LEDs

Infrared LED Camera, IR Lighting

Some cameras come with infrared LEDs surrounding the lens.  These LEDs will emit their own light to illuminate an area.  These cameras are ideal for areas with minimal light available.  If you choose to, you can even place these cameras in a total blacked out area and receive great coverage.

The best advice to give for these cameras is for you to check the distance that the IR LED beams can be shot.  The IR LEDs can range anywhere from 20 meters all the way up to 70 meters and beyond.  Once again look at the spec sheet and make sure the camera you’re considering will cover your required range.

The cameras will operate in color during the day and once the sensor detects increasing darkness the camera will switch over to night vision.  Traditionally at night, you can stand in front of the cameras and can see the IR LEDs giving off a faint red glow.

The Samsung SCO-2120R offers 230 feet of night vision range with IR illumination.

Some cameras offer an IR cut filter and IR LED illumination, such as the GeoVision GV-BL110D, resulting in a true image during the day and illumination at night.

This is a post from: 2M CCTV, an online cctv cameras retailer.

Michael Minieri

ABOUT THE AUTHOR

Michael Minieri is the Principal Security Consultant for Minieri Associates, a security consulting and engineering firm operating nationally and internationally. He began a career of protecting lives and property in 1974 and holds nearly a dozen professional credentials. More information can be found at www.minieriassociates.com

Guest Post by Michael Minieri – Minieri Associates

When most security laymen (and even some security professionals) think to add or increase their physical security measures, CCTV is often the very first thing to come to mind. If CCTV is such an effective security measure, why is it that reality television and the nightly news is so full of CCTV footage of crimes being committed?

Many local governments around the world continue to implement major CCTV systems on city streets and in other public places, frequently with a stated purpose of fighting terrorism. The city of London, for example, has thousands of cameras. It also happens to be the source of one of the most widely circulated CCTV videos of an actual terrorist bombing in history. This incident and others can make a person long for the good ole days of simple convenience store robbery footage!

Worldwide, it is extremely common for the police and others responsible for investigating crimes and apprehending criminals to highly recommend CCTV and to deploy cameras extensively to further THEIR primary objective. CCTV can be an EXCELLENT tool for this purpose! But, private security practitioners are paid to pursue a different objective PREVENTING losses from occurring in the first place.

Certainly, such examples do not imply that CCTV is ineffective as a security tool, but the above examples should clearly illustrate that CCTV  like every other security tool – has practical limitations that must be considered when developing any effective securitysolution. One of the related limitations is among the most commonerrors encountered in security efforts around the globe: Expecting a person to watch one or more monitors and actually detect a crime or other loss at all, much less in sufficient time to prevent it.

Of the six (6) absolutely essential elements of an effective security program, CCTV is probably the very best tool currently available for at least one of those elements. VALIDATION (of the adversarial attack to verify that a response is warranted). Coupled with video analytics, such as video motion detection, CCTV is also the frequent choice for DETECTION (of the adversarial attack such as along a perimeter fence), due to the cost-effective nature of achieving both detection and validation with some of the same investment. By having the video motion feature activate an audible signal at the monitoring position (and displaying the associated camera view automatically), the error of relying on the human to discover the attack through observation is all but eliminated.

This is a post from: 2M CCTV, an online cctv cameras retailer.

Todd Thompson

Todd Thompson - Construction Manager – 2M CCTV

Follow Todd on Twitter

There is anecdotal evidence that suggests security cameras do not deter criminal activity.  People who object to the use of installing a CCTV system in public places sometimes feel the squeeze of encroachment on their privacy, and they will object to using public funds to finance it.  But, there is something to the argument, regardless of private motivation.

People will note that in spite of there being more security cameras posted in large public places, there are still thugs who plunder innocent victims, and there are still terrorists who ride car bombs into a crowded market for their misguided and hate-filled ideologies.

Security cameras cannot touch the motivational factors in such people, some of whom are bent on self-destruction, whose psychological makeup may even encourage them to grandstand their awful deeds.

Degrees of Deterrence

There are, however, degrees of deterrence, besides the absolute prevention of a crime, that are missed in the negative assessment of CCTV.

It should be pointed out that deterrence is not the same as prevention.  Anyone who buys or sells security cameras with prevention in mind is expecting too much.

Deterrence comes in degrees.  A person on a strict diet may do just fine until he walks by a chocolate factory, and sees through the window, those caramel chewies that he craves. The deterrence, in forms of obesity and ill health, may not be enough to cause him to walk on by.  He may think to himself, “I’ll just buy a couple of these, and it will be better than eating a dozen.”  Rationalizing is common to all people, and one would think, especially to the criminal.

By the same token, a person who possesses greater self-control may pass close to the same store and change sides of the street to avoid the temptation.

Security cameras may offer a degree of deterrence to criminals, but one who is motivated highly enough will disregard them or work around them in their planning.

Honesty of Buyers and Sellers of Security Cameras

Buyers of security camera systems, on the one hand, should be careful not to expect too much in the way of deterrence or prevention.  Desperation creates false motivation, self-deception, and unnecessary extravagance in spending.

Sellers, on the other hand, should give customers a more accurate evaluation of the security risks they are trying to address, and they should be cautious about making promises that cannot be fulfilled.

If Cameras Don’t Deter, Then What Good Are They?

For one thing, the primary use of a CCTV system is for the purpose of recording events for later review.  Live surveillance is possible, and with a 24/7 monitoring service or onsite security guards, CCTV systems can trigger a response that may actually prevent a crime in progress.

Generally speaking, though, CCTV systems serve the forensic side of security better than the prevention side.  They are more useful in investigation than they are in prevention.

In this way, the usefulness of security cameras should not be underestimated.  By identifying criminal activity, and perhaps, by locking up the culprits, there is a secondary sense in which a system can aid in prevention.  Locking up the criminals, because they were caught on camera, arrested, tried and convicted, is the real strength of CCTV.  However, it is done by looking back, forensics, as opposed to forward, prevention.

A Balance Should Be Struck

When determining whether there is value in installing a camera system, consumers and business owners should evaluate the type of risks they face.

If it is an absolute must that criminal activity has to be prevented, like in a jewelry store, there should be redundancy in systems.  In other words, there should be 24/7 live monitoring, intrusion detection, safe cabinets, electronic article surveillance, and audible alarms.  All the bells and whistles should be put in place.  Even this type of deterrence does not prevent theft in all cases.

Even then, a CCTV system is useful as a forensic tool as well as an educational one that gives the shop owner critical information that might prevent the next incident.

To suggest anything actually prevents crime by a determined criminal is misleading.  Even the force of police officers in the street, the military guarding against crimes of terrorism, and a highly observant public, cannot always defeat the criminal mind.  However, it can deter the marginal criminal and help put the other ones in jail where they belong.

This is a post from: 2M CCTV, an online cctv cameras retailer.