Network Surveillance Cameras

Linux video camera Security II

A few months back we have dwelled on using a web camera to augment the security of our premises. We have talked about using the ubiquitous web camera to double up as a security camera. But there are several drawbacks in using a standard web camera for security applications:

It has a limited angle of vision – Originally a web camera is designed to have a 45 degree of view. It comes with a pre focused lens and the lens quality is not enough to provide adequate resolution for security purposes.

Even with a higher resolution web camera which provides 2 mega pixel resolution, the required resolution is still limited with the kind of illumination available at a typical office environment.

The illumination level required to provide sufficient detail for security is not enough with ordinary run-of-the-mill web cameras. So we will look at other options – Network Surveillance Cameras (network cameras and IP cameras) in this installment.

In this category we have a bewildering array of cameras available with many connectivity options – Wifi, built-in Network card with/without Image compression software to obviate the need for one at your server end. Many come equipped with optical zoom and Pan/Tilt head assembly. The camera can be controlled through a control panel in the built-in server.

As these cameras are designed for security applications, they have low light sensitivity – often as low as 0.05 lux and coupled with optical zoom in the range of 10 X – you have a decent security camera that can “identify” the license plate number of a visitor’s car in the driveway.

One thing we have noticed in our camera is that the camera lens soon picks up enough dust (possibly owing to the power supply providing a positive electro static charge) which results in a grainy image. So for best results, keep your camera lens/assemblies scrupulously clean.

We also provided a bank of Infra Red LEDs to provide additional illumination wherever required (indoors). Needless to say, almost all cameras we tested contained enough sensitivity in the infra red region. In case you have a doubt, use any infra-red remote control to shine at the camera. You should see a line of white light being emitted from the remote control.

Some web cameras deliberately use an infra-red filter between the pickup device and the lens.

But as we have decided to use specifically crafted Surveillance Cameras, this would not be an issue.

Network Surveillance Cameras

As this is a Hands-on approach to the installation and maintenance of Network Surveillance Cameras, we will start with the selection of cameras first. For outdoor surveillance it would be prudent to go in for a robust enclosure to house the camera and in these days, there are quite a number of manufacturers who build specially designed metal enclosures with industry grade mounting brackets.

Compared with a traditional type CCTV camera installation, Network type camera installation offers several advantages:

1 Cost – Compared with low loss video type coaxial cables, Data networking cables are cheaper.

2. CCTV cameras which provide CVBS (Composite Video with Blanking Signal) output need to have a short run to the distribution amplifier or monitor to avoid high frequency signal loss. All analog systems suffer from this cable distance issues Network cameras use a data encoding system to send binary data across a shared network.

3. Advanced Functionality is easy to implement using software in the case of Network cameras while you need expensive dedicated hardware for the traditional CCTV network.

4. Easy scalability – you can add as many cameras as you require – limited only by the software. You can add individual units as you go.

5. Remote Monitoring and ease of storage: With dropping prices of hard disks and vast quantities of storage space available, you can save to disk all of the outputs from the cameras for later analysis. With suitable authentication, you can monitor your office half way across the globe through internet.

Linux video camera security

Part I

Our commercial video surveillance system had a problem last week. The mains supply unit that feeds the camera, which in turn uses a CCD (Charge Coupled Device) and transmits to the receiver through microwave (2.4 GHz) had failed. To add to our woes, the multiple camera switcher unit had failed as well – possibly owing to a disastrous power supply fault.

It would take some time to sort out this issue and procure replacement units to handle the security of the premises. Someone suggested that we explore using the ubiquitous webcams lying around in our office, coupled with some open source (or commercial) software to handle the perimeter security.

A quick search in the Google for the term – “linux video camera security” returned some 9 million pages. Zoneminder appeared to suit our requirement though our needs were more modest. The site mentions that it is a complete “ all in one Linux GPL’d security camera solution” .

Basically what we needed was as enumerated below:

  1. Option of using inexpensive USB webcams
  2. Option of using a Multi camera setup
  3. Software driven Motion detection
  4. Video streaming through the Net
  5. Option of storing the images generated in the high capacity Network File Server

Browsing through the supplied manual (readme.pdf) showed that Zoneminder would more than suit our requirements.

There are many ways you can download and install the software package.

You can download and compile the source code or download your distro specific RPM to install. You will find that most of the code is written in Perl, which makes managing/ fault finding that much easy for people conversant with Perl.

Linux Video camera security

You will need amongst other things – an Apache server with PHP and Mysql installation. There are other essentials too – libjpeg.a , libpcre.a , ffmpeg or the Berkeley MPEG encoder – if you plan to generate MPEG video. Fortunately if you are with any modern distros, you can use any of their built-in updating to obtain the required libraries.

We will explore how we built from the ground up a very versatile video camera security system with little more than a Linux box and a few readily available Webcams in our subsequent parts.

Targetwoman Earth Day Celebration

We join the Earth day celebration in a small way – by our efforts to disseminate information about practical conservation and tips on Energy saving. Global warming has become a mantra in the media now. Steps to reduce the production of CO2 (carbon dioxide) that contributes to the global warming by the Green House effect can be attempted by anyone who has an interest in preserving Mother Nature.

We provide below some tips and guidance on Energy Conservation:

1. Air conditioning and Heating: Different people require different temperature settings for comfort. We feel comfortable when our bodies lose heat at the same rate as we produce it. Heat production varies with physical activity and our metabolic rates. At the same time, heat loss or heat gain depends on surface temperatures in the room, air movement and air temperature. What all this means is that your comfort factor depends on a lot of factors – one of which is the temperature. Start by setting your thermostat a couple of degrees low.

Energy Efficiency Rating: The energy efficiency rating (EER) of an air conditioner is its BTU rating over its wattage. For example, if a 10,000-BTU air conditioner consumes 1,200 watts, its EER is 8.3 (10,000 BTU/1,200 watts). Aim for a higher EER. Turn off the unit when no one is present. If you have a Voltage regulator for pre-conditioning the supply, turn that off as well.

Better Thermal Insulation: A false ceiling with better heat insulation efficiency can reduce as much as 20 % power bills. An energy-efficient house has a much higher insulation value. It has the ability to resist heat transfer and fasten the heat loss. Materials that weigh a lot store more heat and have high thermal mass. Use of such materials can reduce heating and cooling energy requirements by nearly 25% as compared with mere brick veneer houses.

Power Factor Correction: All electric motors consume reactive power from the supply. Power factor correction capacitors correct the anomaly in the power supply. Discuss with your electric contractor the size of the power factor correction capacitor and its installation. It could save about 10 % from your utility bills.

2. Replace all incandescent bulbs with CFL (compact Florescent Lamps). CFLs are very energy efficient. A 15 W CFL will provide the same amount of illumination as a 60 W normal bulb. But they can’t be dimmed using conventional dimmers. Clean all lamps and lamp shades periodically. A clean lamp and a clean lamp shade enhances light transmission.

3. Inflate your automobiles tires to the manufacturer recommended pressures. Inadequate pressure in your tires can increase rolling resistance by as much as 20 %. Combine trips and chores so that you save on precious fuel. Remove top carriers when not required. They increase wind resistance. Drive at a sedate speed to improve your mileage.

4. Turn off your computers and monitors when not in use unless you are running a data center. A typical Switch Mode Power Supply (SMPS) of a desk top computer consumes about 400 W of energy most of the time. Use a TFT LCD monitor if you are using the conventional CRT (Cathode Ray Tube) monitor. A typical 17 inch CRT monitor consumes about 120 W while the same sized LCD monitor takes in about one fourth of the energy. The heat produced by the CRT also heats up the neighborhood adding to the cooling cost.

5. Invest in automation. A PIR (Passive Infra Red) movement sensor based outdoor lighting can help save considerable energy. You can use them in aisles and elsewhere where manual switching on and off of lights is inconvenient. You will find more tips in energy saving in our article.

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