I'm trying to compare resolution of 520 TV lines and 720*480, Does anyone know which one is better?
2006-09-11 18:55:50 · 3 answers · asked by edwzone 1 in Science & Mathematics ➔ Mathematics
The first television standard was written for CRT displays, and it refers to scanning lines. The standard specified 525 scanning lines in a full frame (1/30 of a second). (I am leaving out interlacing for simplicity.) However, the CRT requires time in between frames for retracing the electron beam from bottom to the top. While this retrace happens, the beam is still scanning some of those 525 lines, with the result that only about 480 actual scan lines appear on the screen. The picture was also specified to have a width to height aspect ratio of 4:3. CRTs do not have vertical lines in their picture, but the bandwidth of the video channel is specified so that the horizontal and vertical resolutions are the same. So if the CRT did have vertical lines, it would have (4/3)x480 or 640 of them. When fixed-pixel displays were introduced, they were designed to match the CRT resolution an so were made with 640 horizontal and 480 vertical pixels. High definition TV is defined in digital terms and deals with pixels even if the display is analog (like CRT). So HD pictures contain either 1280x720 or 1920x1080 pixels.
720 x 480 is the resolution used by DV video for video cameras. The aspect ratio is still 4:3, so the pixels are not "square", they are taller than they are wide. This definitely produces a better picture than 640x480, and is important if the video is taken "anamorphically", which squeezes a widescreen image into the 4:3 format.
2006-09-11 19:18:59 · answer #1 · answered by gp4rts 7 · 0⤊ 1⤋
here it is plain and simple. Due to interlacing on the tv 720*480 is better. Meaning 720 pixels accross, 480 pixels down
2006-09-11 20:51:38 · answer #2 · answered by Anonymous · 0⤊ 0⤋
It's a bit of an apples and oranges comparison. There are other considerations that are important. For example, if there are multiple devices being connected together, it is often best to match the native formats to avoid resampling errors.
Still, in general I'd agree that you're probably better off with the 720x480.
2006-09-11 21:32:42 · answer #3 · answered by or_try_this 3 · 0⤊ 0⤋