resolution of 720 X 480i or 720 X 576i. For a 16:9 aspect ratio, this translates into an active resolution of 960 X 480i or vertically lowpass filtering the image. A progressive dis- 960 X 576i. play has no limit on the line-to-line changes, SO is capable of providing a higher-resolution image (vertically) with- out flicker. Enhanced-definition Today, most broadcasts (including HDTV) are still transmitted as interlaced. Most CRT-based displays are Enhanced-definition video is usually defined as having still interlaced while LCD, plasma, and computer dis- 480 or 576 progressive active scan lines, and is commonly plays are progressive. called "480p" and "576p," respectively. For a fixed-pixel (non-CRT) consumer display with Video resolution a 4:3 aspect ratio, this translates into an active resolution of 720 X 480p or 720 X 576p. For a 16:9 aspect ratio, this translates into an active resolution of 960 X 480p or Video resolution is one of those "fuzzy" things in life. It is 960 X 576p. common to see video resolutions of 720 X 480 or 1920 X The difference between standard and enhanced defi- 1080. However, those are just the number of horizontal nition is that standard-definition is interlaced, while samples and vertical scan lines, and do not necessarily enhanced-definition is progressive. convey the amount of useful information. For example, an analog video signal can be sampled at 13.5 MHz to generate 720 samples per line. Sampling the High-definition same signal at 27 MHz would generate 1440 samples per line. However, only the number of samples per line has High-definition video is usually defined as having 720 changed, not the resolution of the content. progressive (720p) or 1080 interlaced (1080i) active scan Therefore, video is usually measured using lines of lines. For a fixed-pixel (non-CRT) consumer display with resolution. In essence, how many distinct black and a 16:9 aspect ratio, this translates into an active resolu- white vertical lines can be seen across the display? This tion of 1280 X 720p or 1920 