Tuesday, 24 January 2006

Interlaced Scan Rendering (TV broadcast formats)

Interlaced Scan Rendering (TV broadcast formats)

NTSC

NTSC is based on a 525-line, 60 fields/30 frames-per-second at 60Hz system for transmission and display of video images. This is an interlaced system in which each frame is scanned in two fields of 262 lines, which is then combined to display a frame of video with 525 scan lines. NTSC is the official analog video standard in the U.S., Canada, Mexico, some parts of Central and South America, Japan, Taiwan, and Korea.

PAL

PAL is the dominant format in the World for analog television broadcasting and video display (sorry U.S.) and is based on a 625 line, 50 field/25 frames a second, 50HZ system. The signal is interlaced, like NTSC, into two fields, composed of 312 lines each. Several distinguishing features are one: A better overall picture than NTSC because of the increased amount of scan lines. Two: Since color was part of the standard from the beginning, color consistency between stations and TVs are much better. In addition, PAL has a frame rate closer to that of film. PAL has a 25 frames per second rate, while film has a frame rate of 24 frames per second. Countries on the PAL system include the U.K., Germany, Spain, Portugal, Italy, China, India, most of Africa, and the Middle East.

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