Who needs an HDTV?

Won't come close to a good HDTV with high-speed video processing, conversion to 24 fps for Blueray DVDs, and on and on.

Plus, until you get to around 40 inches, much of it's lost anyway.

_What_ is lost below 40 inches, and why?

Bill Horne Temporary Moderator

(Please put [Telecom] at the end of your subject line, or I may never see your post! Thanks!)

So it can do 720P no problem.

Unfortunately, scaling up from the lower resolution to the higher resolution isn't very good. With multisync CRTs, it was possible to change the resolution of the video monitor to whatever the computer wanted it to be, but in the flat panel monitor world, you pretty much have to operate the monitor at the native resolution. If you set your computer for a different resolution than the monitor, the monitor will have to rescale the video and the end result is much poorer

Consequently if you want to display 720p, you need a monitor with 720 pixels across it, or an even multiple of 720. Anything else and you are losing resolution in the scaling process. The alternative, of course, is to mask it down and live with a smaller image size.

--scott

I thought the 720 was lines of resolution, not pixels across. If that's the case I've got better than 1080.

I know the aspect ratio on SDTV is 4:3, and on HD it' 16:9, so by that math I'd need 723 lines of 1280 pixels, and my display is set at

Anyone else have more info?

'lines of resolution' on one axis is _exactly_ the same as 'pixels' on the other axis, when talking about a fixed-pixel based display.

Stack a number of rows (columns) of pixels side by side, with every other one on/off, and you'll see the lines form in the other direction.

the math is 720x1280, not 723. on a 800x1280 display, the display software typically leaves the top and bottom 40 pixels black, allowing an exact 1:1 pixel mapping. Some stuff will replicate every 9th row -- a 10/9 vertical 'stretch' -- which gives a 'full screen' image at the cost of a bit of distortion.

Thanks for confirming that it's vertical resolution. So in essence I'll get a bit of letterboxing on this laptop. No biggie. I much prefer net based vids and haven't had many crashing issues.

Right, it's pixels top to bottom, which is the same as what video guys call 'vertical lines of resolution.'

It doesn't MATTER that you have more than 1080... it only matters that you have 720 or an integral multiple of 720. If you scale the image up by a non-integral size factor, you lose quality.

Right, so in that case you could just add some black borders and crop it down a touch rather than scaling.

--scott

WRONG!!! 'pixels top-to-bottom", is the same as what the video guys call "*HORIZONTAL* lines of resolution".

Its _easy_ to get confused. But remember if you light up the same pixel position in adjacent _vertical_ columns, this draws a =horizontal= line. to wit:

.......... .......... .......... OOOOOOOOOO .......... .......... .......... .......... ..........

Subject to how you define 'quality', that is. If the scaling is in a non- integral _rational_ ratio that can be expressed using integer values that are close to each other, one can simply replicate selected scan lines with very little "observable" impact.

AND, if you employ more advanced image-processing techniques -- e.g., things like 'edge detection' -- you can actually end up with a scaled-up image that appears 'sharper' than the "original". There will, in all likelihood, be some differences from 'reality' (i.e., in comparison with the same image at a native resolution equal to the scaled-up size) -- the techniques involved do introduce possible 'artifacts' in the image sharpening process.

Those quibbles aside, _simple_ (linear interpolation) scaling does result in some degradation of image quality _IF_ the scale factor is non-integral.