| 释义 |
PAL (Phase Alternate Line) A television standard established in Western Germany,The Netherlands, and the United Kingdom in 1967. PAL addresses problems of uneven color reproduction that affect the NTSC standard due to phase errors associated with electromagnetic signal propagation. PAL inverts the color signal by 180° on alternate lines, hence the term Phase Alternate Line. PAL currently is used in much of Western Europe, Australia, and Africa. PAL is characterized as analog, with 625 interlaced scan lines. There are 640 pixels per line, with 576 dedicated to the active picture. The frame rate is 25 fps, and the aspect ratio is 4:3. Competing standards are NTSC (National Television Standards Committee) and SECAM (SÉquential Couleur Avec Mémoire). See also analog, aspect ratio, frame, frame rate, interlaced scanning, NTSC, phase, pixel, propagation, SECAM, signal, and television. |