Glossary Term: JPEG
A JPEG is a way of storing images on a digital device such as IP CCTV cameras, digital cameras and mobile phones. JPEG is a compressed format, giving a greatly reduced file size compared to image dimensions. The compression is adjustable but greater compression rations will result in loss of data and as such grainier pictures.
JPEG stands for Joint Photographic Experts Group, who created the format when trying to produce a smaller file size for transmitting images across the internet. Most IP CCTV cameras support this format due to the reduced file size which helps to reduce bandwidth and hardware usage.
Glossary Term: IP Camera Software Development Kit (SDK)
A Software Development Kit or SDK is a library of code used for creating applications, usually on specific platforms, to work with a specific IP camera, or range of IP cameras. With IP security cameras SDKs usually consist of code designed to access and retrieve images from a camera over the network, or to alter settings. SDKs are similar to Application Programming Interfaces (API) in that they allow remote communication with IP CCTV cameras, but SKDs differ in that they are created to allow camera-native communication to be embedded into proprietory applications.
Included with an SDK is full descriptive literature describing how the code works, how it should be used and often includes working examples to help developers understand how to integrate the code with their own. SDKs tend to cover an entire range of devices but may contain code chunks which are specific to one particular model.
Most IP camera SDKs are very tightly controlled by the manufacturer, often requiring registration and the signing of non-disclosure agreements to protect their software and intellectual property.
Glossary Term: Outdoor IP CCTV Surveillance
IP cameras can be installed in both indoor and outdoor locations giving you the flexibility to choose the right camera for your needs.
Outdoor IP cameras come in two distinct variations. They can either be suitable for outdoor use with the addition of an external enclosure (such as an Axis 214 or Panasonic BB-HCM580) or they can be placed outdoors with no additional protection (such as a Mobotix M22M-IT-D22 or Panasonic BL-C160).
External enclosures are normally rated against the ingression of solid matter such as dust, dirt etc. and against water penetration (rain, snow etc.). The rating is normally expressed as an IP number and the values attributed will give the overall protection rating of the enclosure. Most housings also come with fans and heaters and are thermostatically controlled to keep a reasonable ambient temperature so the camera view doesn’t steam up with condensation in colder climates.
Cameras which require no additional enclosure benefit from being a lot more compact than traditional CCTV enclosures. This offers discreet outdoor surveillance. They are also much easier to install, normally supporting Power over Ethernet so they can be connected up with a single cable with no need to hire an electrician to run power cables.
Remember, outdoor cameras can also be used for security around the home. There are small, unobtrusive, easy to install cameras which are ideal for monitoring your property, vehicles, garage, entranceways etc. and some even have infrared lights or bright white LEDs to enable you to see better in low-light conditions.
More information
For your convenience, we create product bundles for cameras which require additional outdoor enclosures to ensure that when you order an outdoor camera from us you get all the parts you need:
Glossary Term: Interlaced Scan
Interlacing is a way used by IP camera manufacturers to speed up the refresh rate of their cameras.
An IP camera sensor is made up of a mesh of pixels. The colour value of each pixel is transferred to the computer as a series of numbers which the computer then interprets back into colours and outputs on your screen. However, in particular with megapixel cameras, there can be millions of pixels to retrieve, which can require a large amount of processor time, either slowing the camera down, or pushing the price up as more powerful processors need to be used.
Since IP cameras take many pictures per second, the time between images is very small, leaving very little time for objects to move significantly. With this in mind, interlacing was developed whereby instead of reading each line of pixels one after another, only every second line is read. On the first pass the camera will read lines 1, 3, 5, 7 and so on. Once the last line has been read, the camera returns and reads lines 2, 4, 6, 8 etc, meaning that each frame only half the image is read, saving time and bandwdth. This means the camera can achieve a greater frame rate without requiring more powerful hardware.
The downside with this is that since objects are moving between shots, the position of the objects in view will change between shots. With slow moving objects this is fine, but with fast moving objects such as cars or people, a tearing effect occurs along the edges of the object.
The image on the left is from a progressive scan camera, the image on the right is from an interlaced scan camera. As you can see, the difference with moving images is huge.
Glossary Term: Pixel
Pixel is short for picture element and is the term used for each of the small dots of colour on a computer screen which make up a picture. It also refers to the small receivers on IP camera sensors which transfer the light recieved into data.
Each pixel has a colour value of red, green and blue. Varying the values of these three colours will alter the overall colour of the pixel. With IP cameras, the sensor records the red, green and blue values for each of these pixels and then transmits the values to your computer, which then rebuilds them in an image on your screen.
Glossary Term: Wireless IP Camera
There are IP cameras available today which have wireless connectivity built-in as standard allowing them to be placed around the home without the complication of running Ethernet cable to each room. Other IP cameras also offer wireless connectivity as an additional add-on such as a wireless card. These cameras can be placed around your home or business to provide IP CCTV monitoring across your wireless network (WLAN).
Benefits of wireless transmission
Wireless cameras takes the hassle out of installation. There’s no need to run cables discreetly under floorboards or through walls. All you need to do is locate a power outlet to provide power to the IP camera, the data will be transmitted over the WLAN.
Install virtually anywhere. With no reliance on cables you can place in hard-to-spot places for discreet surveillance.
Easy to move. If you want to change your camera’s position its easy with wireless connectivity. Just unplug the camera, move it and then plug it back in. The camera will reconnect to your wireless network automatically.
Once connected you won’t be able to tell the camera is connected wirelessly. It works just as well without the cable as it does with it!
Standards and Encryption
Most wireless cameras include support for either IEEE802.11b or or IEEE802.11g with the majority supporting both. This means they are compatible with the most common WLANs available. Another thing to look out for is wireless encryption support. Again most wireless IP cameras today support a full range of wireless encryption protocols. So if you use WEP at home with a 128-bit hex key or WPA-PSK for your business your camera should be able communicate effectively.
Glossary Term: Tampering Alarm
The Tampering Alarm is an intelligent feature found on IP CCTV cameras which have a strong focus on security, such as tamper/vandal resistant IP cameras. The kind of cameras which are designed to be installed in exposed locations where there is a active threat of people interfering with it.
It’s easy to set up. Once activated the camera will notify you if it has been moved, obscured, covered or sprayed with paint. They way it works is simple. When the camera is first turned on it will take a few seconds to examine the scene. After the examination process is complete the scene is locked and any alteration to the scene can cause an alert. This does mean however that if the light changes drastically in a scene (such as turning a off a light) then the camera will generate a tampering alert. Some cameras have the facility to ‘turn off alerts from dark images’ so that it isn’t affected by light changes but the downside of that is it will no longer trigger an alarm if the camera is covered or sprayed, only if it has been moved.
Tampering Alarms are a useful tool which provide instant feedback when a camera has been compromised, something which could take a CCTV operator a lot longer to discover.
Glossary Term: Network Video
Network Video, when used in security surveillance applications (IP CCTV), refers to a system which allows live motion video to be broadcast over IP-based networks, such as a Local Area Network (LAN) or the Internet, for the purposes of live monitoring or recording.
Network video uses a computer network as the means of transporting video and audio data rather than the traditional point-to-point cabling you would associate with analogue CCTV. This allows your digitized video and audio streams to pass through the same Ethernet cables which may already will be run throughout your organisation and business.
Furthermore, because network video is digitized to travel along IP based networks it can be viewed remotely from any computer in the world which has access to the Internet. This allows 24 hour surveillance of your property or business. Being purely digital also means the data is stored digitally and will retain its quality, color and will not be degrade over time in the same way as analogue recordings.
Glossary Term: Network Video Recorder (NVR)
A Network Video Recorder (NVR) is a digital device which sits on your IP CCTV network to recieve live image/video streams and record them digitally to a hard disk.
An alternative to PC/server-based recording, the NVR offers a less complex installation, is easier to set up and has a user-friendly interface for day-to-day use. As the NVR is solely designed for IP CCTV surveillance, the embedded operating system is optimised to handle the maximum number of cameras the unit supports. This means that you can be confident that the NVR will be reliable, stable and perform as intended, unlike a PC/server based approach which has many variables that could affect performance.
Multi-site installations are simplified with the use of NVRs. If your organization spans multiple locations you can centralize the security monitoring to one location by linking an NVR at each location to managment software. Most NVRs today offer live video monitoring too and also allow remote access so a number of people can log in and view their cameras on the same machine simultaneously using secure logins.
Glossary Term: Bandwidth Limitation
Bandwidth is an increasingly precious commodity both on your local network and across the wider Internet. Where IP video and CCTV cameras are concerned bandwidth is an important factor to consider when designing an IP CCTV system or looking to convert an obsolete analog CCTV system to IP CCTV.
Luckily, many IP cameras incorporate a facility to limit the amount of bandwidth used up by the camera at any one time. This allows those planning CCTV systems and networks incorporating IP CCTV to plan bandwidth usage with confidence.
Large IP CCTV networks should always include some form of bandwidth limitation across all or some IP cameras in order to mitigate the potentially damaging results network saturation can have on the efficacy of an organisation’s network and the security of that business’s premises.
Important bandwidth-related factors to consider when designing an IP CCTV system:
1. Compression / quality
2. Frame rate across the network
3. Individual frame data size
4. Total number of cameras in the system
5. Times when the cameras will be actively consuming network bandwidth
These factors cumulatively construct the total bandwidth use for the system and should be calculated with the bandwidth limitation features of available IP cameras in mind. It may well be that in commissioning a large networked CCTV installation you should specify cameras with this feature or encounter potential problems of scalability down the line.
Issues with regard to bandwidth use are more significant when considering IP video transmitted over the Internet and special consideration must be given to those streams delivered this way.
Planning an IP CCTV system or network must be done carefully with regard bandwidth and the bandwidth limitation feature available in many IP cameras can help.