What resolution are NTSC (Video) Images?
It is best to first remember that TV is an analog signal and its parameters are defined by the National Television Standard Committee (NTSC). • NTSC Resolution is 460×350 Television Lines (TVL) • NTSC has a 4:3 aspect ratio, your computer screen is something else, so converting screen video to NTSC is not 1:1. • NTSC Broadcast defined as V = 525 Lines but ~ 44 lines are used for non-video data thus typically only only ~ 480 Lines are “Viewable” • NTSC Video is interlaced so in a single scan only 1/2 the vertical lines are displayed hence in a single scan in NTSC resolution = 240 Vertical Lines. 2 scans make up a full frame of 480 lines. • The aspect ratio of NTSC is defined to be 4/3 = 1.33333 Since the horizontal scan is “analog” thus NTSC Horizontal Resolution = 480 * 1.3333 ~ 640 hence 1 frame of interlaced video is ~ 640 x 480 pixels. Remember that this signal is interlaced so this does not actually represent the “Resolution” of a video camera. Video resolution is defined as number
