HDTV provides up to five times higher resolution and twice the linear resolution compared with traditional, analog TV. Furthermore, HDTV comes with wide screen format and DVD-quality audio
HDTV Impact on Video Surveillance Market
HDTV is now starting to have an impact on the video surveillance market, as customers ask for higher image quality standard. The possibility of clearer, sharper images is a long sought quality in the surveillance industry, i.e. in applications where objects are moving or accurate identification is vital. Some of these requirements can be met with megapixel network cameras. However the notion of “megapixel” is not a recognized standard but rather an adaptation of the industry’s best practices and it refers specifically to the number of image sensor elements of the digital camera. In contrast, a network camera that complies with any of the given HDTV standards is guaranteed to provide a certain resolution, frame rate and color fidelity, thereby ensuring video quality at all times.
Development of HDTV
Experimental HDTV systems in, for example, the U.S. were all rejected because of their high bandwidth requirements. It soon became evident that a successful HDTV standard required better efficiencies. A joint project between MPEG and the Video Coding Experts Group of the International Telecom Union, ITU eventually resulted in the H.264 standard, also known as MPEG-4 Part 10/AVC. This compression technique not only made HDTV broadcast possible, but also economically viable. HDTV usually assumes a wide screen aspect ratio of 16:9 and horizontal resolution of 1920 pixels with progressive scan. Consequently, this creates a frame resolution of 2,073,600 (1920×1080) pixels.
The H.264 standard is an open, licensed standard that can reduce the size of a digital video file – without compromising image quality – by more than 80% compared with the Motion JPEG format. There is no doubt that H.264 was a necessary prerequisite for introducing HDTV in video surveillance.
Benefits of HDTV in Video Surveillance
Working with progressive scan, network cameras with HDTV performance deliver true color representation and clear images even if the object is moving fast. This makes it a highly attractive solution for surveillance operations where greater image detail is required, such as at retail stores, airports, passport controls, casinos and highways.