TV screen resolution upscaling question

Forums › Home Theatre (including HTPC and EPG Collector) › TV screen resolution upscaling question

D1023319

524 posts

Ultimate Geek

ID Verified

#57516 16-Feb-2010 09:28

Hi,

Purely out of personal interest, I am interested in the number of lines that build up the image on my LCD tv screen.

I know my flat screen can display max 1080 vertical lines (depending on source, eg 1080i for tv3).

I also know that my TV on 100hrtz function has the processing power to create additional frames where it extrapolates the movement on the screen. (noting number of lines remains the same).

My question is, if modern tv's can create extra frames, do they also have the ability to create extra lines? I ask as this isnt a issue I have seen discussed anyhere.

My presumption is my TV is more than 1080 pixels wide, so I assume each current vertical line is more that one Pixel wide. ( some sites say 3 pixels wide). Hence my idle curiosity if there was oportunity for improvement.

Cheers

sbiddle

30853 posts

Uber Geek

Retired Mod

Trusted

Biddle Corp

Lifetime subscriber

#299413 16-Feb-2010 09:32

Your TV is presumably a Full HD 1920x1080 panel.

If you are viewing content that is a lower resolution than this then your TV or STB had to scale the content to view it.

D1023319

524 posts

Ultimate Geek

ID Verified

#299578 16-Feb-2010 20:54

Hi,

Yes my TV Samsung 650 is full 1080 and I know about the various source formats.

My question is philisophical about why cant TV's use onboard processing power go above 1080.
To me this seems reasonable as they current can insert extra frames for the 100htz feature.

Cheers

richms

28220 posts

Uber Geek

Trusted

Lifetime subscriber

#299649 17-Feb-2010 00:55

they couild, but it would mean the panel was more expensive.

There are some panels that have higher resolution but they are usually 30" computer monitors - too small for HT use.

Having more pixels without the source to deliver them is as stupid as getting a 1080p tv now, when you are just watching crap old dvds on it. Only benifit is reduced visibility of the pixel structure on the screen, and if you are so close that you are seeing 1080 panels then a bigger house is what you need.

Richard rich.ms

Batman

Mad Scientist
29773 posts

Uber Geek

Trusted

Lifetime subscriber

#299651 17-Feb-2010 01:25

firstly your tv is 1920 pixels wide not 1080. (well, roughly, more or less)

i dont think creating frames is an accurate description (i dont know, any lcd experts?)
panasonic claims 480hz subdrive. sony has 200hz. so your 100hz is chicken feed really.
it's to do with scanning - scanning the lcd panel 100 times a second surely cant be that hard? ac current moves electrons between your house and the powerstation 50 times a second. (err right?)

to show more than 2 million pixels (> 1920x1080) is exponential (in a way, i'm not a mathematician) every time you increase the resolution. but yeah i'm sure they're capable.

i've been wondering how my samsung can process 1080i tv3 freeview feed where my computer (without the modern gpu) can't. anyone?

D1023319

524 posts

Ultimate Geek

ID Verified

#299709 17-Feb-2010 10:28

richms:
Having more pixels without the source to deliver them is as stupid as getting a 1080p tv now, when you are just watching crap old dvds on it.

I dont agree with this as in my experience the processing power of the TV is all important for picture quality when comparing Freeview Terrestrial vs my dvd player (not blueray) vs the SD saturn channels.

By way of example, my series 5 samsung shows a great deal of difference in screen quality depending on the source, however on Series 6 samsung, the difference is almost minimal.

So thats why I was musing that processing power permitting, I think it is reasonable to go beyond 1080
( using 1080 as a generic reference name and noting Jokers97 comment that "to show more than 2 million pixels (> 1920x1080) is exponential" ).

Unfortunately there is little information on this topic on the web hence why I posed the question here.

Cheers

samwooff

219 posts

Master Geek

#299758 17-Feb-2010 13:43

Hey

I'm not 100% sure if i understand what you're trying to ask but I'll do my best. The pixels on your screen is a physical characteristic which you cannot change, on an LCD anyway.
http://en.wikipedia.org/wiki/File:TVPixel.jpg
This picture should give you a good idea as to why.

Panasonic and others subdrive is different to your 100hz mode.
The subdrive refreshes exactly the same image for the length of a frame, equating to 600 times or whatever it may be per second. So a 600hz subdrive assuming a 50hz signal would be 12 refreshes per frame of the same image.
100hz on the other hand uses very complex algorithims to guess an intermediate frame or two in between the ones it is being fed from the source.

To joker97: From what I've heard computers don't seem to like interlaced signals, not sure of the exact reasoning behind this, something to do with the processing meanwhile tvs have been designed to accept interlaced signals as that was what tv originally was broadcast in.

You can get a higher resoloution than 1920x1080(several manufacturers had 3840x2160 tvs on display at CES) but that would require you to buy a new tv.

Desktop: i7 920, GTX 275, asus P6T, antec 1200, 6gb ram, 1tb spinpoint f1, 1tb spinpoint f3, Logitech Z2300, Zero DAC, Shure SRH440
Laptop: Toshiba satellite, T5300, Go 7300
Home Theatre: 32" loewe CRT, Harmon kardon amp, dvd player, image 418 speakers, rega planar 25 turntable :)

richms

28220 posts

Uber Geek

Trusted

Lifetime subscriber

#299788 17-Feb-2010 14:25

The only display that likes interlaced is the old CRT. Anything else has to deinterlace it.

The reason computers dont like it, is that it has traditionally been a CPU consuming, slow process to deinterlace footage when importing it and loads of software either doesnt do it and just combines the 2 fields into a frame (see heaps on youtube where that has happened) or has crap algorhythims do do it.

Deinterlacing is easily done on the gfx card on playback now, and there are encoders available that will use that to re-code video for portable devices too, so doing encodes of interlaced stuff for a portable player or iPod or whatever is not the massive slow challange it was many years back.

Richard rich.ms

Sharesies

Trade NZ and US shares and funds with Sharesies (affiliate link).

Masterpiece

247 posts

Master Geek

#299962 17-Feb-2010 22:16

D1023319: Hi,

Purely out of personal interest, I am interested in the number of lines that build up the image on my LCD tv screen.

I know my flat screen can display max 1080 vertical lines (depending on source, eg 1080i for tv3).

I also know that my TV on 100hrtz function has the processing power to create additional frames where it extrapolates the movement on the screen. (noting number of lines remains the same).

My question is, if modern tv's can create extra frames, do they also have the ability to create extra lines? I ask as this isnt a issue I have seen discussed anyhere.

My presumption is my TV is more than 1080 pixels wide, so I assume each current vertical line is more that one Pixel wide. ( some sites say 3 pixels wide). Hence my idle curiosity if there was oportunity for improvement.

Cheers

To be technically correct there is 1080 horizontal lines and 1920 vertical lines.
In NZ Broadcast HD is 1080i (interlaced) or 720p (progressive) and of course there is still 576i (interlaced) PAL legacy signal.

The actual sizings are, 1920*1080i25/50, 1280*720p25/50, 720*625i25(576visible lines)

Pixels/Lines make up the whole, being the frame where by the frame rate is at 25 or 50fps, the i/p indicates interlaced or progressive, just noting all modern panels and displays show a final progressive image so any interlaced signal is always converted to progressive.

When is comes to scaling the TV or source can do the scaling, adding extra lines to make the full frame scaling to match the resolution.
ie a 1280*720p50 or 720*576i25 signal is scaled to 1920*1080p50 where by the missing lines are created from localised pixel information. This is where quality upscalers really show their abilities and poor ones show their artifacts.

This relates to your question, can your display upscale or scale, Yes is the answer, how well really depends on quality of the electronics.

The best image tends to be one where the least scaling takes place,Send a 1920*1080p24/50/60 signal to your 1920*1080 display from a Blueray player. Noting the HD Freeview broadcast dispite having 1080i signal on TV3 and 720p is of lower quality than potential BD quality of typically 1080p.

Me:"I'm not a robot!"

ET: "Maybe; you have some freewill, but you chose your path by arrangement"

Me "That sounds like a program with no freewill?"

ET: "We will catch up when you end this cycle"

Me: "Sounds like a 'KPI'!"

ET: "Did you read the terms and conditions?"

Me: .....