Well here is a short note on a gigantic subject.
My main purpose is to collect some information about
video resolution designations like 720p
This discussion mostly glosses over refresh rates.
- 480i - old fashioned TV
- 720i - bogus, essentially never used.
- 720p - 1280 x 720 progressive
- 1080i - 1920 x 1080 interlaced
- 1080p - 1920 x 1080 progressive
HDTV broadcast is all done in the widescreen 16:9 aspect ratio format.
The designation number (like the 720 in 720p) indicates the
number of horizontal scan lines in the image (modern displays
don't really scan, but never mind).
The letter p or i indicates progressive or interlaced.
Progressive is better.
Interlaced means that every other line gets updated on a screen
refresh, reducing bandwidth at the expense of flicker.
Progressive updates all lines on every refresh.
- 720p looks as good as 1080i - so don't waste your money.
- 1080p and 720p look essentially the same on 32 inch or
smaller monitors - so don't waste your money.
Have any comments? Questions?
Drop me a line!
Adventures in Computing / email@example.com