The Digital Fact Book - Quantel

HDR, HDRIHigh Dynamic Range Imaging techniques allow a greater dynamic range of exposure thannormally possible, with the intention of accurately representing the wide brightness rangeof real scenes ranging from direct sunlight to shadows. This is sometimes used withcomputer-generated images or photography (by taking several pictures of a scene overa range of exposure settings) and it can provide a large amount of headroom for theadjustment of images in post production.HHD readyThis describes a television that can display the recognized 720 and 1080-line formatsbut does not include the tuner or decoder needed to receive the signals.HD RGBThis refers to HDTV signals in RGB form rather than Y,Cr,Cb form. The difference is that HDRGB is a 4:4:4 signal that can carry the full bandwidth of each of the R, G and B channels,whereas HD (TV) is normally considered to be in 4:2:2 form where the color differencesignals have a more restricted bandwidth. Generally, the 4:2:2 form of HD is sufficientfor many television applications and can be carried in its uncompressed form by a singleHD-SDI connection. HD RGB is often used for critical keying shots for television, and fordigital cinematography. The availability of a suitable VTR (HDCAM SR) makes working withthe format generally more affordable.HD-SDISee SDIHDTVHigh Definition Television. A television format with higher definition than SDTV. While DTVat 625 or 525 lines is usually superior to PAL and NTSC, it is generally accepted that 720-lineand upward is HD. This also has a picture aspect ratio of 16:9.While there are many picture HDTV formats there is a consensus that 1080 x 1920 is apractical standard for global exchange of television material – a common image format.Many productions are made in this format.See also: 24P, ATSC, Common Image Format, DVB, Table 3100