Pixels: sizes, quantity, and remapping

My LCD is 768x1366 pixels. This seems to be a very common pixel
configuration. Where did they get that number? Yes, 768 is 3 times
256, but 1366 is kind of an odd number. 1366 isn't even a multiple of
16. If they had wanted a multiple of 256, why not pick 720x1280 as
1280 is a multiple of 256? If they had really wanted multiples of 256,
why not 768x1280 (with rectangular pixels like most plasma sets).

Is there one pixel for each color, RGB? or has technology combined the
three colors into one pixel?

What happens when a 1080i (1080x1920) signal is received. Are some of
the transmitted pixels (TP) in the signal: (A) merged with adjacent
TPs, or (B) simply ignored.

What happens with a 720P signal? As my viewing pixesl (VPs) are more
than my TPs, does the TV sometimes present the same TP in two adjacent
VPs, or perhaps two TPs are spread into three VPs?

Just curious?

Good questions. I hope someone answers. I know just enough to know what
to ask, but not give informed answers. A few of the upconversions of
standard broadcast tv I've seen to full HD have not been good. Full HD...
1080p or even 720p. I've heard this is a function of the converter, not a
limitation of the process. So far it has prevented my from buying one.

I'll try and answer a few of these, but first, I must comment on your
syntax. Usually, the horizontal resolution is listed first and then the
vertical such as 1366x768, this is a standard way of describing
resolutions for monitors. It is not necessarily wrong to reverse them,
but you can confuse people sometimes.
Also, the high definition spec is for a resolution of either (1) 1280
(horizontal lines) x 720 (vertical lines) of progressive scan video
(i.e. 720p), or (2) 1920x1080 of interlaced (every other line every
other pass) video (i.e. 1080i)
Don't worry about 1080p, you don't need it. (Boy, I'll get flamed for
that one for sure)

NadCixelsyd wrote:
My LCD is 768x1366 pixels. This seems to be a very common pixel
configuration. Where did they get that number? Yes, 768 is 3 times
256, but 1366 is kind of an odd number. 1366 isn't even a multiple of
16. If they had wanted a multiple of 256, why not pick 720x1280 as
1280 is a multiple of 256? If they had really wanted multiples of 256,
why not 768x1280 (with rectangular pixels like most plasma sets).

Its not about the multiple (or factor) of the pixels, its the ratio of
one to the other. 1366 (divided by) 768 gives you a ratio of 1.77 (or
16:9). This is what you want for a wide screen 16:9 ratio TV. If you
have a 4:3 ratio TV (non-widescreen TV), then you want the pixels in a
similar ration such as 640x480. The "HD" resolution for a 4:3 ratio
1024x768. This is what most "HD" plasmas are right now. If this is your
resolution on a wide screen plasma, then you have rectangular pixels,
not square pixels as you suggest.
One more note on this is that if the resolution is not in a 16:9 ratio,
then it is technically not a true high definition resolution. HD calls
for both high vertical resolution (720p, 1080i) and a wide screen 16:9
format.

Is there one pixel for each color, RGB? or has technology combined the
three colors into one pixel?

For LCD's, you have three "pixels" for every pixel that you see, one
each of red, green, and blue. They don't count those though for
resolution since it is the combination of those three that produces the
color. Plasmas don't work that way, I'll defer that discussion to
someone else "in-the-know" on that technology. In a CRT, its just
electrons hitting the screen to make the colors, so it doesn't have
pixels in the same sense.

What happens when a 1080i (1080x1920) signal is received. Are some of
the transmitted pixels (TP) in the signal: (A) merged with adjacent
TPs, or (B) simply ignored.

The signal is either converted in the box that receives it (i.e. cable
box, sat. box) to the correct resolution (720p) or the TV converts it
to the right resolution when it receives it. This discussion is very
popular with some people on which one is better. To answer your
question, its more like (A) than (B). The conversion process uses the
data to recreate the picture in the correct resolution. However, there
are not as many "extra" pixels as you think though. 720p gives you
921,600 pixels at 60 frames per second, and 1080i gives you 1,036,800
pixels at 30 frames per second.

What happens with a 720P signal? As my viewing pixesl (VPs) are more
than my TPs, does the TV sometimes present the same TP in two adjacent
VPs, or perhaps two TPs are spread into three VPs?

This depends on the monitor (i.e. which TV you own). Some TV's will
scale the video to fill all the pixels, and others will just give you a
one-to-one pixel picture (leaving black edges). Most I would think
would scale it since it is really just a zoom type operation.
I'll let someone else give their opinion on that too though.
Just curious?

On Jan 2, 3:16 pm, "Doug" wrote:

Also, the high definition spec is for a resolution of either (1) 1280
(horizontal lines) x 720 (vertical lines) of progressive scan video
(i.e. 720p), or (2) 1920x1080 of interlaced (every other line every
other pass) video (i.e. 1080i)

I believe the definition of HD is 720 or more vertical lines. I don't
think there's a horizontal standard. Some sets that claim to be HD
are only 1024 pixels wide (see next paragraph)


Its not about the multiple (or factor) of thepixels, its the ratio of
one to the other. 1366 (divided by) 768 gives you a ratio of 1.77 (or
16:9). This is what you want for a wide screen 16:9 ratio TV. If you
have a 4:3 ratio TV (non-widescreen TV), then you want thepixelsin a
similar ration such as 640x480.

The screen size must have a ratio of 16:9 (1.78:1), but the pixel
count needn't be. Many plasma sets in the under-50" range tend to be
1024x768 pixels. In order to achieve 16:9, the pixels must be
rectangular. (e.g. the pixels are 33% wider than they are high).
I've also noticed that plasma sets with this low pixel count tend to
omit that information from the box cover.