vga -> composite -> vga (possible?)

**Nav_Attack** · 04-03-2004, 12:08 AM

i was wondering if it was possible to convert VGA to composite and then back to VGA.. reason being i've got a composite input LCD now, but needless to say the resolution sucks ***, and im looking into getting a VGA screen. I've already got the cable laid well for the composite wire, and would rather not re-lay vga cable. i doubt its likely, but i'm holding on to a slim, slim, fading hope.

**Bobby Digital** · 04-03-2004, 12:15 AM

Originally Posted by Nav_Attack

i was wondering if it was possible to convert VGA to composite and then back to VGA.. reason being i've got a composite input LCD now, but needless to say the resolution sucks ***, and im looking into getting a VGA screen. I've already got the cable laid well for the composite wire, and would rather not re-lay vga cable. i doubt its likely, but i'm holding on to a slim, slim, fading hope.

Even if it were possible (I'm not sure), you definately wouldn't get the quality of a VGA screen so having one would be pretty much pointless. You'll be better off to lay some VGA cable all the way.

**Nav_Attack** · 04-03-2004, 12:18 AM

i figured (sigh). don't know whats worse --- getting the system up and running in the first place or wanting to upgrade it within 15 mins of getting it up.

**Almost a Ghost** · 04-03-2004, 12:26 AM

It is possible, but it's like taking a 640x480 image resizing it to 320x240 and then resizing it to 640x480.

**Nav_Attack** · 04-03-2004, 01:50 AM

hehe. so essentially, its ugly?

**gork** · 04-03-2004, 12:26 PM

It would also be pretty expensive.

You can convert VGA to NTSC with many devices out there; the problem is that you lose a lot of the resolution when you do it. NTSC specifies only 525 lines of total resolution and generally only 480 are visible. The idea of "resolution" is dependent on many other things including how the signal is carried to a monitor (component Y,Pb,Pr/s-video/composite, etc), but needless to say, even if you did get a very good vga scan converter, the best you'd ever be able to reconstruct from an NTSC picture is probably 640x480

And that's just the image resolution problem. NTSC can't show as many colors as VGA. The color gamut is smaller. Here's an example:

The colors on the TOP row are the brightest hues that VGA can manage. The colors on the bottom row are the brightest hues that NTSC can encode. A lot of TV's perform gamut-expansion to make the colors appear less dull, but unless you get a very expensive upscan converter to convert NTSC back to VGA you probably won't get this benefit and, so, you'll lose some color information also. (As an aside, you can see that blue is the brightest color that NTSC can show. That is why most electronics blank the screen to blue!)

Still, if for some reason you need to do it, I'd recommend using a Cheese Video Box as the lowest cost NTSC->VGA upscan converter out there right now..