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Ultra High Definition Video
hovermike writes "This story about UHDV (Ultra High Definition Video) comes from the NY Times. Here are a few specs from the article: 'picture size of 7,680 by 4,320 pixels'; 'UHDV's beefed-up refresh rate of 60 frames per second (twice that of conventional video), projected onto a 450-inch diagonal screen with more than 20 channels of audio'; '22.2 sound: 10 speakers at ear level, 9 above and 3 below, with another 2 for low frequency effects'; AND THE KICKER, 'All those sound channels and all those image pixels add up to a lot of data. In test, an 18-minute UHDV video gobbled up 3.5 terabytes of storage (equivalent to about 750 DVD's). The data was transmitted over 16 channels at a total rate of 24 gigabits per second.' Don't think I'll wait to buy regular 'old' HDTV..."
regfree link here
FPS != Refresh rate
Refresh rate is the actual rate at which the screen refreshes. Frames per second is the number of frames that go into the framebuffer of your video card.
If you have 30 frames per second and not notice a flicker, but as long as it remains at a constant 30 you will rarely notice. There will be no flickering either.
If you have 60Hz refresh, you will notice that because that is the rate at which your eye sees the light of the phosphors turn on and off, and your eye can detect luminance more than any other portion of the picture signal. As long as the phosphors remain lit for long enough for your eye not to detect the flickering you will not notice.
With 30 frames per second and 72Hz, you don't see the flickering because the same frame is drawn to the screen multiple times regardless of framerate. If you have ever watched a PAL television, did you notice the motion stuttering? Most won't, and that runs at 30 frames per second. The refresh rate of PAL is 60Hz, so there is a noticable flicker (NTSC uses 50Hz at least in the US)
If you have 90 FPS at 72 Hz, you will not see more than 72 of those frames. The screen is not drawn that fast. (I use 72Hz as last I read that was the minimum "healthy" refresh rate). The real reason you notice the difference between 60fps and 90fps in quake is that it is likely only an average, and what you are actually getting is 20 frames sometimes, and 60 at others. Higher average means that most of the time you have a higher refresh rate.
This was reported last year UHDV.
"A plan fiendishly clever in its intricacies"- Homer Simpson
I'm still waiting for "conventional" high-definition programming to become mainstream. Sure, we now have consumer level HD cameras but the local news broadcasts are still SD. Alias is in HD, and Jennifer Garner makes my HDTV purchase worth it (don't tell my wife), but every commercial is still in SD.
The FCC-mandated transition to digital broadcasts probably won't help make HD content mainstream either. Stations may be broadcasting all digital, but they'll still be broadcasting Gilligan's Island reruns at SD or (gasp) upconverted to 1080i.
UHDV technology may be the future, but the expense of producing content won't make it mainstream. Oh, and Slashdot covered this before.
I saw a 60 fps movie at Expo86 in Vancouver, 18 years ago. It had incredible realism.
The high frame rate eliminates the strobing effect that occurs when the camera pans, or an object moves quickly across the screen. I noticed the strobing when watching LOTR in the movie theater, but the effect isn't visible on TV.
HDTV (ATSC) supports 1080i and 720p.
Mea navis aericumbens anguillis abundat
Many TV stations found out that their sets looked really cheesy when they tested them with HD video cameras. Not to mention the faces of the "talent'.
Mea navis aericumbens anguillis abundat
Wow, a whole paragraph where you managed not to say anything... 30fps and you won't notice a flicker, and something about it not being constant, and then another something about not flickering.
True (the only thing I can say you've gotten right), yet a completely pointless, unrelated fact.
First off, you've got it completely backwards. NTSC is 60Hz, at 29.97FPS, while PAL is 50Hz at 25FPS.
Second, you're saying most won't see the flicker of 60Hz here, but in the paragraph above you were just saying that people WILL notice the flicker at 60Hz (but not at 72Hz, whatever significance 72 holds)... So which is it, or better yet, what are you really trying to say.
Bad moderators! Why in the hell did this completely unintelligable, factually incorrect mess of a post get modded up? Now I head over to Medamod, so I can make sure these positive mods get marked as unfair.
Slashdot gets worse every day... Pipedot: News for nerds, without the corporate slant
As pointed out above, definately some errors in this post.
:)
The NTSC standard is not 60Hz refresh. A NTSC tv draws even lines first, then odd lines. Each one of these is called a 'field'. There are 60 fields per second, but they are put together to make a 'frame' There are 30 frames per second. (when they added in sound/colour in there, it got switched down to 29.997 or somethign stupid...bandwidth issues)
Anyways, this even-odd line drawing is called interlacing. It tricks the eye into aaalmost seeing 60 frames per second.
NTSC TV's, unlike monitors/video games, dont have seperate frame/refresh rates, because inside the TV, its all analog circuitry driving the electron beam which is driven directly off of the RF signal to display what it does on the screen. Not like a video game where the computer might be generating 120fps, but the monitor refreshing at 75Hz. In this case, the monitor redraws itself completely(called progressive scan), 75 times a second. When your video game framerate is higher than your monitor refresh you will certainly experiance 'tearing' This is when the frame changes in the middle of a monitor drawing cycle.
Most people who want a nice looking picture will turn on vertical synchronization . This makes it so that no frame changes in the middle of a monitor drawing by limiting the maximum framerate to the monitor refresh rate, and synchronizing the two. Once this is on, it becomes a lot more like NTSC, except not interlaced. One video game 'frame' is served up every monitor 'frame' and it all looks very nice.
The reason a video games looks so shitty at 30fps and TV doesnt is twofold.
1. What the above poster said, that 30fps is an average, and if you are getting 30 average, you are probably sometimes getting more than 30, sometimes getting less...you will really notice the 'less'
2. Video games dont have motion blur. On video cameras/your eyes, moving objects are automatically blured because your eyes dont 'update' all that fast. On video games a distinct frame without motion blur is drawn..each frame could be removed to make a sharp picture. Not so on tv. (oh and i know about some hardware/software inserting some crappy motion blur routines..the fact that you can plainly see it means it looks nothing like the real thing
It's easier to fight for one's principles than to live up to them.
From the article: "But NHK is familiar with long-term projects: it began developing the HDTV standard in 1964, and the first high-definition content arrived only in 1982." And HDTV is finally filtering down to the masses, 40 years later. They're not just defining random specs, they're defining them for decades later down the road when people can support the bandwidth.
Pixels and Resolutions
name Herbert
status educator
age 60s
Question - Presently there is quite a bit of talk about pixels. Each
digital camera manufacrer claims there camera has 3 million pixels,
another 3.5 million, on and on. This reminds me of the 50's & 60's when
Hi-Fi audio manufacturers claimed there equipment had a wider bandwidth
than its competitor. So the question is what is the resolution of the
human eye, and can the figure be quoted in pixels?
I will answer as much as I can, but your questions about the limits of the
human eye should really be directed to a specialist in the theoretical
limits of the human eye. Right now that is a question that has been
researched quite well, and there are several formulas to help predict that.
From what I understand, the resolution of the human eye is not measured
directly in pixels, but by the angular difference between two points of
light that can be resolved. Here is a very good article on that:
http://www.madsci.org/posts/archives/may9 7/864446241.Ph.r.html
From this article, if I have done the math right, I understand that a
typical person has a maximum resolution of about 17000 point sources per
inch. This doesn't really equate to pixels, but, pixels can be changed into
pixels per inch, and that should be close enough.
Digital cameras do brag about their resolution, because, well, it really
does matter. It matters because their resolution is so poor compared to a
real cameras, or a decent printer that it is pathetic.
For example, a really good digital camera might have a resolution of 2160 x
1440. If you made that into a 4x5 picture, you have a resolution of about
400 pixels per inch. Which isn't bad, but photo quality printers print at
2400 pixels per inch. If you decided to make it into a 8x10 photo, you end
up with about 200 pixels per inch. This was considered excellent quality 10
years ago, but is very poor quality by todays standards.
So, compared to the human eye, a real camera, or good printed material,
digital cameras aren't there yet. They do use a wide variety of software to
try and enhance the quality for printing, but there is still room for
improvement.
That doesn't mean digital cameras don't have a use. If you need pictures in
a digital form to be displayed on computer screens, then you have something.
A computer screen has a resolution of about 72 pixels per inch, and digital
cameras are definitely better than that. Also, since it is basically one
step from taking the picture to downloading it onto your computer, you get
better results than if you took a picture, developed it, and then scanned it
in, not to mention much faster results. With the popularity of the web,
digital cameras are great for creating images to place on a web site.
I hope this helps.
--Eric Tolman
http://www.madsci.org/posts/archives/may 97/864446241.Ph.r.html
From this article, if I have done the math right, I understand that a
typical person has a maximum resolution of about 17000 point sources per
inch. This doesn't really equate to pixels, but, pixels can be changed
into pixels per inch, and that should be close enough.
It would seem to me that if the resolution of the human eye is one
arcminute at 10 inches, then the maximum resolution of the human eye is
found as follows:
You find the circumference of a circle of radius 10 inches, which comes to
62.83 inches. One 1/21600th (or 1/60th of a degree) of this is 0.002908
inches, the minimum possible perceptible distance by the human eye at 10
inches.
To get this much resolution, you need 343, not 17,000 pixels per inch.
Of course if you get even closer, the story changes, but what the
resolution of the human eye is at some other point that 10 inches I am not
sure.
Even taking a hypothetical one inch of distance with the exact same eye
resol
That depends on how far you sit from the TV. At some multiples of screen size you only need 2048p to hit the max for the human eye. At others you need UHDTV. If you don't have good eye sight and sit 3 - 4 X of the TVs width from the TV 1080p is already maxing out the resolution detectable by the eye.
o n. html
http://clarkvision.com/imagedetail/eye-resoluti
Sure, you'll have less flicker at higher refresh rates, but a higher refresh rate will not improve the frame-rate, of course. Something like 10FPS video will still look plenty choppy at 120Hz, and you will notice that.
It's not your post that bothers me, it's the fact that it got modded up.
It often seems like a few moderators have points to use, and will mod-up anything that sounds remotely authorative... I've tested this theory myself in the recent past, and made a couple posts that were all fact, yet completely incorrect, but got modded-up to +5 anyhow.
Whenever anyone asks how the
Slashdot gets worse every day... Pipedot: News for nerds, without the corporate slant
An A-size engineering drawing sheet is 48 x 36 inches (Metric A4 is slightly different, but similar). Paper is capable of better, but useful detail on a drawing is around 200 dpi. This means that a single engineering drawing is about 9600 x 7200 pixels = 69,840,000 pixels. Of course, these aren't moving images.
IMHO 200 dpi is about right for viewing without noticeable digitizing effects - moire, rasters, etc. Pencil lines at this resolution don't have visible jaggies if they're antialiased, and don't look out of focus either.
It's easier to be a result of the past, but more fun to be a cause of the future! http://www.spacefinancegroup.com/
The resolution of the human eye is about 2500x2500 (6-7,000,000) cone cells (color) and 35000x35000 (120,000,000) rod cells (grey). Not evenly spread and the rods are not individually sensitive with multiple rods triggering the one nerve. See this more detail.
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It's wrong that an intellectual property creator should not be rewarded for their work.
It's equally wrong that an IP creator should be rewarded too many times for the one piece of work, for exactly the same reasons.
Reform IP law and stop the M$/RIAA abuse.