Over the last 10 years, the CCTV industry has seen a major shift from analog to digital networking solutions for surveillance applications. In the next few years, the industry will see the adoption of High-Definition (HD) IP Video into mainstream CCTV systems, as in consumer electronics. For HD IP cameras to be adopted by mainstream video security applications, the issues associated with high data rates and storage need to be solved. This is now being addressed with the recent launch of HD IP cameras with low data rates.
Advantages of HD IP
The advantages of HD IP cameras have been well documented, but there are three areas where they can provide real benefits:
General Surveillance — A single HD megapixel camera can replace several standard 4SIF cameras, thereby reducing costs. An HD megapixel camera can see more detail in the same field of view or view a wider field of view at the same level of detail.
Forensic Detail — Many existing analog CCTV systems simply do not provide enough resolution or quality for forensic evidence. Megapixel cameras solve many of these quality/resolution issues. They are ideal for applications where the system wants to identify and record faces, vehicle license plates or objects.
Digital PTZ — HD megapixel cameras can digitally zoom quicker and with greater detail than analog cameras, while still recording the whole picture for later analysis. This provides superior performance and is more reliable than mechanical PTZ mechanisms.
Surveillance can definitely benefit from HD technology. Currently, typical applications for HD IP cameras include retail point of sale, banks, casinos, car parks, building entrances, military installations and city center monitoring.
In order for HD megapixel cameras to be adopted for mainstream use, the following technology hurdles have to be overcome:
Lens — Megapixel cameras require a higher resolution lens than ordinary CCTV cameras to maximize the picture quality. These lenses are readily available but are expensive in CCTV mounts — although this will change with the higher volumes from mainstream adoption.
Sensor — Megapixel cameras use the same CMOS image sensors as used in still digital cameras, whereas analog cameras typically use CCD sensors. This is likely to change with the adoption of sensors from the HD TV/Video industry. A higher density of pixels on the same-sized sensor means there is less light falling on each pixel. Each pixel, therefore, has less sensitivity and needs more light — and the “noise” in the sensor has a larger impact because it is a higher percentage of the signal. This is why first-generation HD IP cameras typically had a poorer low-light characteristic than analog cameras; however, sensor technology is improving quickly.
Video Compression — Arguably the most important factor, due to its impact on network bandwidth and storage requirements. HD megapixel cameras are unlikely to be adopted for mainstream use until low-bandwidth camera designs are readily available. This is now starting to happen with the launch of HD IP cameras.