EDTV vs HDTV
There was a time when there was just TV, and you were never required to know about the technology used before buying one. You never had to go into technical details regarding its picture quality, like resolution, frames per second, aspect ratio, etc. Nowadays, you have to know about SDTV, EDTV, HD Ready, HDTV, and many more to come, in order to buy the best you can afford. Display technology has been through a progressive phase, from SDTV to EDTV, and then finally, to HDTV.
EDTV evolved from SDTV, which incorporated 480 scan lines, along with 45 extra blank lines allotted for resetting the display time. The display type for SDTVs are cited as interlaced (480i or 525i). This display type did not prove to be successful for large screen TVs, as it caused poor picture quality due to the visible jagged lines. Progressive scan displays came into the picture, and these are usually known as an enhanced definition TV, i.e. EDTV.
While an EDTV supports only progressive scan displays, HDTV supports both progressive scan displays and interlaced displays. Interlaced displays paint the line alternately in two passes, whereas progressive scan displays paint all of the lines in one pass. EDTV is specified by 480p, which has 480 scan lines, whereas HDTV is specified by both 720p (720 progressive scan lines) and 1080i (1080 interlaced scan lines). When large screens are taken into consideration, more scan lines result in a better resolution and picture clarity. This enhances the overall picture quality on large screens.
EDTV displays high-definition broadcasts by down-converting the signals to 480 scan lines, thus resulting in a loss of clarity. On the other hand, HDTV broadcasts high-definition programs very well, preserving the extra clarity.
HDTVs prove themselves superior to EDTVs by rendering high-definition broadcasting with a better picture quality. However, when we talk about watching 480i standard broadcasting, all HDTVs are not found superior to EDTVs. A high quality EDTV that has a better de-interlace device, has greater capability to process the interlaced signals than a low quality HDTV, that is furnished with a low-end de-interlace device.
When it comes to watching TV programs, you can watch most of them on an EDTV, as there are limited HDTV programs. This is the same with DVD’s and DVD players available on the market. DVD’s can be easily displayed on an EDTV, but not on HDTV, as it requires HD DVD. Similarly, most of the DVD players are a progressive scan, which gives an EDTV a signal as its output, and hence they can’t be connected to HDTV.
Summary:
1. EDTV supports only progressive scan displays, while HDTV supports both progressive scan displays and interlaced displays.
2. EDTV is specified by 480p; whereas HDTV is specified by both 720p and 1080i, which yield a better picture quality.
3. EDTV has less clarity while down-converting high definition broadcasts, and contrarily, HDTV preserves this extra clarity.
4. While watching 480i standard broadcasting, a high quality EDTV has a greater capability to process the interlaced signals than a low quality HDTV.
5. All TV programs, DVDs, and DVD players are compatible with an EDTV; whereas, most of them are incompatible with HDTV.