576-line Video

576 线视频 is a digital standard-definition format derived from the 625-line, 50 Hz analog television system, with an effective image resolution typically of 720×576. The remaining scan lines are used for blanking, synchronization, and auxiliary information; “625 lines” and “576 effective lines” describe different aspects of the same system. 576i typically uses interlaced scanning at 50 fields per second, corresponding to 25 full frame cycles; while 576p transmits a complete picture line by line, using either 25 or 50 frames per second. DVD-Video in PAL-related markets generally uses 720×576 and employs pixel aspect ratios to generate 4:3 or 16:9 displays. The stored pixels are not square.

Strictly speaking, “PAL” is an analog color encoding standard; while the digital term 576i is historically related to PAL, the two should not be used interchangeably in all digital contexts. The color matrix, field order, pixel aspect ratio, and encoding of digital video must be described separately.

Deinterlacing or upscaling 576i to 1080p or 4K only changes the output grid and scanning method. Effective detail remains limited by the standard-definition source, format conversion, and compression; incorrect field order or treating film pull-down as standard interlacing can result in motion artifacts.