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 Why is checkerboard 3d inferior to standard 3d? 
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Sharp Eyed Eagle!

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Hey Guys,

I really want to get the new viewsonic 3d 1024x768 DLP 120hz projector. I heard it uses checkerboard 3d and I read some posts on this forum saying it's not as good as ordinary stereo 3d! Can someone please explain firstly what checkerboard 3d is and then tell me what's the difference between this kind of 3d and the ordinary 3d with other projectors like the depthQ?

Also does anyone know if it's worth getting the new viewsonic using this checkerboard 3d?

I read that the viewsonic has been designed for the new nvidia 3d vision shutter glasses but I would like to know if it can also be used with passive glasses. Most DLP tv's can be used with both nvidia 3d vision shutter glasses and passive glasses like the ones used by real d who provide them for the 3d cinemas across the world. The reason I would like the projector to do passive as well is because I hope the viewsonic will be compatible with consoles. The PS3 demo at ces 09 was being demonstrated using passive glasses by real D on a DLP flat panel TV. So if I am going to spend a large sum of money on a projector I would rather get one that can do both formats. nvidia for pc games and passive for console games.

Many thanks in advance

EDIT: to add to this thread, do you know if this viewsonic dlp projector I talk of above has dual view, you know that's that new dlp feature where two people can be watching different images at full screen off the projector by wearing their own 3d glasses?


Sat Jan 31, 2009 6:20 am
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Checkerboard halves the resolution of the image.
It's like a modern version of interlaced 3D but slighly better quality, yet it can't rival full resolution 3D.

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Most DLP tv's can be used with both nvidia 3d vision shutter glasses and passive glasses like the ones used by real d who provide them for the 3d cinemas across the world.

It is my understanding that DLP TVs = shutter glasses only.
For passive glasses with DLP you need an additional polarizer that dynamically switches the polarisation pattern. Which is why RealD sells it's own projector. I do not know any TV that has this feature.

The CES 2009 playstation 3 tech demo used a specially made prototype display with a circular polarized interlaced filter, similar to the Zalman monitor, just much bigger and higher definition.

The playstation 3 is not currently capable of outputting full resolution 3D at 1080p because the hdmi v1.3 port does not have enough bandwidth.
At best the PS3 can output interlaced (like the CES demo) or checkerboard. But Sony has not announced ANYTHING officially so there is absolutely NO GUARANTEE that any current projector or TV will work in 3D with the PS3.
So i strongly advise not to buy in advance with the PS3 in mind or there is a very high chance that it won't work.

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Sat Jan 31, 2009 8:30 am
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Sharp Eyed Eagle!

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Many thanks for your reply

Much appreciated

I can see now that I would much rather prefer full resolution 3d. But it's interesting you mention the ps3 CES demo used checkerboard that means if they do go down that route for the consumers it should be compatible with the new viewsonic checkerboard projector. I will have to wait really and see what happens on the ps3 side of things.

You seem very technically minded in this area, so I wonder if you can answer me on this

When do you think we will see a true 120hz PC input projector under $3000 with the following features:

dual view mode
nvidia 3d vision ready, passive 3d ready on a single projector if possible in the future
1080p 3d
120 frames per second gaming in non stereo 3d eliminating the need for vsync

Now using different display systems like LCOS, LCD, DLP, LED, Laser, utilizing some or all of the above features under $3000

Many thanks in advance


Sat Jan 31, 2009 9:13 am
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I wish i could answer that question, unfortunately i'm no sony or viewsonic engineer, just a well informed consumer so i guess a crystal ball would give you a better answer than mine.

But if i were to guess, i'd say :
1080p nvidia 3d ready : probably an announcement at CES 2010 and a product launch during the following year
any resolution passive on single projector : probably a prototype at CES 2010 but no product until Stereo3D is mainstream

Dual view : totally unknown, first it would not be compatible with the current nvidia 3D glasses, you'd need a new glass version, i don't know how the nvidia IR emitter works but you may also need a new version of the ir emitter if it can't be upgraded. And then with polarized displays you'd need a different pair of glasses than for 3D... so let the passive 3D projector come first and then later the manufacturers may add a dual view mode... but i'm not even sure there would be enough people interested.
You could also get it earlier but if would be software elumated (the streams must be managed by the computer)

about v-sync in 2D mode : It's not display related.
For 2D mode it's already purely optionnal. No matter what the refresh rate of the display, V-synched images will always look better.
It's because of the way graphics cards work to generade 3D images. You can perfectly play any game in 2D with v-sync off.

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Sat Jan 31, 2009 10:53 am
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One Eyed Hopeful

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I always heard controversy over that the checkerboard pattern does or does not 1/2 the resolution. I have heard good technical explanations from each side so I would like to ask you or another member to give a real good technical explanation of this please.

I have the 61 HL-T6187S LED DLP which does checkerboard, this issue effects me obviously and while I do enjoy my glasses the 3D resolution I pick in game looks exactly like the resolution I pick when 3D is not enabled.

Further more when I am in a game with the Nvidia 3D glasses and 3D is turn off I can see my picture resolution as intended and full. When I hit the 3D button on the pyramid it turns on 3D instantly and the resolution does not looks modified or halved.

I have go by my eyes and say that this does not 1/2 the resolution in my setup. It will take my input and the DLP engine does each eye @ 60hz. I have a nice set up and I am pretty intelligent with use of 3D equipment and have a lot of experience. So I will say it doesn't.

If someone could prove me wrong because my eyes see different in my set up let me know I would love to heard a deep technical reason. I would appreciate it... Thanks :P


Sun Feb 01, 2009 9:23 am
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It does physically halves the resolution but in an intelligent way.
The checkerboard pattern is an optical illusion designed to make the half resolution image look better than it actually is.

It's like interlacing with a proper deinterlacing filter. It's lower quality than the original progressive full resolution picture but does not look bad.

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Sun Feb 01, 2009 9:38 am
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There is a whitepaper available over here that should answer your questions.

I do have to stand corrected, by the way. I was playing around with HL2 the other day and was testing the perception of the "single pixel" question on a chain link fence. When you are far away from the fence then you can faintly see the checkerboard pattern miss every other pixel. However, this goes away as soon as 2 pixels are displayed because then checkerboard pattern can replicate the original data. Even with this though, I REALLY had to look for it and the vast majority of users wouldn't notice this because they would be engrossed by the 3D experience in general.

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Sun Feb 01, 2009 10:58 am
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From what I have read it seems that as checkerboard 3d is not full resolution 3d it brings a lot of incompatibility issues. But it is a lot more cost effective than full resolution 3d. The incompatibility means many people have to convert their stereo 3d video formats to the checkerboard format before they can view them. Now the other day I found that the company reald which are providing the equipment for the new 3d cinemas across the world have started selling these things they call pods. They are real time converters, quite pricey. Unfortunately they don't seem to have a pod that can do all formats instead they have several pods for each formats costing from $500-$2000. These do real time conversion of all sorts of stereo 3d formats into the checkerboard pattern so you don't have to do any converting. http://www.reald.com/index.php/page/index.php/page/80

Now can anyone tell me with this new viewsonic checkerboard projector. Will it be possible for me to buy many of the new 3d blueray movies and view it using the nvidia shutter glasses or other glasses? Without needing to convert the movies? If it's also possible to use the projector with the PS3 if they go down the route of doing stereo 3d?

Many thanks in advance


Sun Feb 01, 2009 4:11 pm
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One Eyed Hopeful

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With interlacing you actually do loose half the resolution.
With checkerboarding each eye looses half the resolution, however the other eye sees the other half of the pixels. So together you do have full resolution. It works fore verything except fine details as your brain isn't capable of stitching together an image at pixel level.

So it does actually project full HD resolution, however each eye can only see every other pixel.
It's definately better than interlaced which is half resolution, but not as good as polarized full res.

This way they support 3D at 60FPS. The DLP engine doubles this to 120hz so each eye sees 60FPS.
It would be nice if they let you do full-screen page flips at 30fps.


Sun Feb 01, 2009 7:27 pm
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interlaced is also half resolution for each eye and with the two eyes together you get full res.

Counting pixels, interlaced and checkerboard are perfectly identical.
It's just that the line by line interlacing makes it easy to notice, whereas the checkerboard pattern hides the resolution loss.

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Sun Feb 01, 2009 8:04 pm
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smoothy wrote:
From what I have read it seems that as checkerboard 3d is not full resolution 3d it brings a lot of incompatibility issues. But it is a lot more cost effective than full resolution 3d. The incompatibility means many people have to convert their stereo 3d video formats to the checkerboard format before they can view them. Now the other day I found that the company reald which are providing the equipment for the new 3d cinemas across the world have started selling these things they call pods. They are real time converters, quite pricey. Unfortunately they don't seem to have a pod that can do all formats instead they have several pods for each formats costing from $500-$2000. These do real time conversion of all sorts of stereo 3d formats into the checkerboard pattern so you don't have to do any converting. http://www.reald.com/index.php/page/index.php/page/80

Now can anyone tell me with this new viewsonic checkerboard projector. Will it be possible for me to buy many of the new 3d blueray movies and view it using the nvidia shutter glasses or other glasses? Without needing to convert the movies? If it's also possible to use the projector with the PS3 if they go down the route of doing stereo 3d?

Many thanks in advance


thanks guys for the info above from all 3 post ...

Just so you know the Tri-Def player will do this for you bluray on the fly with out converting them. i have been doing this for a while. I automatically does the checkerboard for any directx filter playing through the media player including mkv's and what no.

i been watching 1080p in 3d for months now and it great


Mon Feb 02, 2009 8:48 am
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Sharp Eyed Eagle!

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1wayjonny wrote:
smoothy wrote:
From what I have read it seems that as checkerboard 3d is not full resolution 3d it brings a lot of incompatibility issues. But it is a lot more cost effective than full resolution 3d. The incompatibility means many people have to convert their stereo 3d video formats to the checkerboard format before they can view them. Now the other day I found that the company reald which are providing the equipment for the new 3d cinemas across the world have started selling these things they call pods. They are real time converters, quite pricey. Unfortunately they don't seem to have a pod that can do all formats instead they have several pods for each formats costing from $500-$2000. These do real time conversion of all sorts of stereo 3d formats into the checkerboard pattern so you don't have to do any converting. http://www.reald.com/index.php/page/index.php/page/80

Now can anyone tell me with this new viewsonic checkerboard projector. Will it be possible for me to buy many of the new 3d blueray movies and view it using the nvidia shutter glasses or other glasses? Without needing to convert the movies? If it's also possible to use the projector with the PS3 if they go down the route of doing stereo 3d?

Many thanks in advance


thanks guys for the info above from all 3 post ...

Just so you know the Tri-Def player will do this for you bluray on the fly with out converting them. i have been doing this for a while. I automatically does the checkerboard for any directx filter playing through the media player including mkv's and what no.

i been watching 1080p in 3d for months now and it great


Many thanks for your input,

Do you know if the tri-def player is compatible with the nvidia 3d vision shutter glasses?


Mon Feb 02, 2009 9:17 am
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1wayjonny wrote:
thanks guys for the info above from all 3 post ...

Just so you know the Tri-Def player will do this for you bluray on the fly with out converting them. i have been doing this for a while. I automatically does the checkerboard for any directx filter playing through the media player including mkv's and what no.

i been watching 1080p in 3d for months now and it great

Really? I have tried BluRay with TriDef Media Player before and it wouldn't work. Whats your secret?

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Mon Feb 02, 2009 1:56 pm
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BlackShark wrote:
interlaced is also half resolution for each eye and with the two eyes together you get full res.

Counting pixels, interlaced and checkerboard are perfectly identical.
It's just that the line by line interlacing makes it easy to notice, whereas the checkerboard pattern hides the resolution loss.


So if you draw a horzontal 1pixel wide line on the screen only one eye will be able to see it?


Mon Feb 02, 2009 6:54 pm
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A note on the Samsung DLP TV's -- the picture is slightly defocused, using what they call "wobulation." This tends to blur the checkerboard images enough that they look like a full-res image (at the cost of some maximum sharpness).


Mon Feb 02, 2009 7:21 pm
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chimchim wrote:
A note on the Samsung DLP TV's -- the picture is slightly defocused, using what they call "wobulation." This tends to blur the checkerboard images enough that they look like a full-res image (at the cost of some maximum sharpness).


I'm not sure this is very effective. If you draw a 45 degree angle line in paint only one eye will be able to see it. Thin objects moving on the screen "shimmer" too.


Mon Feb 02, 2009 7:50 pm
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There is more info here (though a fair bit of BS in this article, whoever wrote it should be shot!!)

http://www.pcmag.com/article2/0,2817,2338401,00.asp

For me, this is an absolute deal breaker either way - think I'll just stick with my 'superior' xr-10x which cost a fraction of the price.

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Wed Feb 04, 2009 6:09 am
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hmmm. My old Infocus X3 could do full page flip at 85hz.

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Wed Feb 04, 2009 6:40 am
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pixel67 wrote:
hmmm. My old Infocus X3 could do full page flip at 85hz.


Exactly, there are so many projectors out there much cheaper, and for this reason much better, than the new InFocus - they have totally shot themselves in the foot making this a checkerboard unit afaic. I'd MUCH rather have full pageflipped resolution that the extra 35hz - 85hz I can use for unlimited periods of time with no eyestrain whatsoever.

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Fri Feb 06, 2009 7:10 am
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bastian74 wrote:
So if you draw a horzontal 1pixel wide line on the screen only one eye will be able to see it?

If you send this 1 pixel horizontal line to the display in 3D mode : yes
This is why small text is usually impossible to read on interlaced displays.

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Last edited by BlackShark on Fri Feb 06, 2009 7:16 am, edited 1 time in total.



Fri Feb 06, 2009 7:15 am
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Sharp Eyed Eagle!

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chrisjarram wrote:
There is more info here (though a fair bit of BS in this article, whoever wrote it should be shot!!)

http://www.pcmag.com/article2/0,2817,2338401,00.asp

For me, this is an absolute deal breaker either way - think I'll just stick with my 'superior' xr-10x which cost a fraction of the price.


I just read that article, a few things I would like to point out which have left me wondering with questions

It said cut and paste 'Currently the most common approach — used by both IMAX and the ViewSonic projector — is to combine alternating images for the left and right eyes with glasses built around LCD shutters. The glasses synchronize with the projector so each eye sees only the image meant for that eye. The synchronization is maintained either using pulses of light on the screen generated by the projector or (as with the PJD6220-3D) infrared light generated by additional hardware near the screen.'

Does that mean imax uses shutter glasses? I always thought they were using circular polarized glasses? The above cut and paste did mention pulses of light on screen. Could it be imax uses the pulses of light with polarized glasses?

is 1400x1050 a widescreen resolution?

Can this viewsonic projector only do 120hz 3d in 1024x768 and say 3d at 85hz in 1400x1050?

I have heard it cannot do high definition but 1400x1050 is high definition it can correctly display 1280x720p it won't be native but you can have that content with say 2d movies displayed at 1400x1050 right? It can also accept 1080i but that will be down scaled to 1400x1050 or will it go to it's native resolution of 1024x768?

It does checkerboard 3d in it's native resolution of 1024x768 at 120hz, now the big question is can it do full resolution 3d at say 1024x768 or 1400x1050 at 85hz+?

Sorry for all the questions

I hope you guys can clear these things up which would help anyone else that have any questions about this projector

Many many thanks in advance


Fri Feb 06, 2009 7:16 am
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Any resolution can be widescreen providing you use an anamorphic pixel ratio (non-square pixels)

Some 3D theaters use shutter systems, some use circular polarisation, others use dolby3D.
I'm not sure if there is a IMAX norm about this.

3D theaters do not use the checkerboard pattern but some of them use shutter glasses.

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Fri Feb 06, 2009 7:31 am
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My understanding of checkboarding is this:

Player takes 2 full 1080p frames in 1/30th of a second, one for left eye and one for right eye, and breaks them into 4 new frames, the first one being left eye half-res checkerboard, the second being right eye half-res checkerboard and the following 2 frames are the other half checkerboards for those frames. My assumption is each frame sent to the display is actually 2 half frames 'interlaced' to be split for each eye, with the following frame the other half of the image for each eye. The net effect is: half image left eye, half image right, second half image left, second half image right. This sequence happens 30 times or 120 individual partial/half frames per second. Aside from this, depending on the implementation, the display actually does some processing to interpolate the missing pixels in each single-eye sub-frame to reduce the perception of the checkerboard pattern.

If this explanation is accurate, the end effect is 2 full 1080p frames (one for each eye) in each 1/30 sec slice, a derivation of 1080p60. In any given frame yes there is half the resolution, but overall I don't consider this a 'loss of resolution' at all. So is there really any 'loss' of resolution, practically speaking?


Thu Feb 18, 2010 11:37 am
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Neo42 wrote:
Player takes 2 full 1080p frames in 1/30th of a second, one for left eye and one for right eye, and breaks them into 4 new frames, the first one being left eye half-res checkerboard, the second being right eye half-res checkerboard and the following 2 frames are the other half checkerboards for those frames.
This is not correct. What you describe is a variation of 1080p30 format; however similar 4-field scheme is used in 1080i stereo, except that each subfield is not checkerboard sampled but interlaced (vertical subsampling).

In TI's checkerboard 1080p60 format, the left picture is always sampled at odd positions ("white" cells on the chessboard), and the right picture is always sampled at even positions ("black" cells on the checkerboard). The result is 1080p60 video stream that contains two half-resolution left-right frames in each 1080p frame. In order to display the stereo video on a frame-sequential stereoscopic display, each left-right frame is up-sampled to full-resolution 1080p by averaging the neighbouring pixels (aka bilinear interpolation). The result is 120 Hz video which contains alternating left-right frames, each at 1080p60, presented with the help of LCD shutter glasses.

Side-by-side checkerboard is another variation which is a half-resolution side-by-side format (horisontal subsampling) where each sub-picture can be checkerboard sampled, as explained in the 3D portion of HDMI 1.4 spec. This format is more flexible and left-right pictures can be sampled at different combinations of odd and even sampling.


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DmitryKo-

I think I just got mixed up on the streaming format coming out of the player/display adapter-- each frame contains 2 offset checkerboard half-res images, or a combination of left and right eye images. The following frame will be the other halves 'essentially' giving you 30 full frames per eye, per second or 1 half frame for one eye every 1/120th of a second (alternating between each eye)


Thu Feb 18, 2010 4:42 pm
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This isn't the DLP checkerboard indeed, it sounds like the sensio format that we've been able to see in Avatar the game.

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Thu Feb 18, 2010 5:31 pm
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I've played Avatar in 3D on PS3 via DLP checkerboard and found it to look quite good.

I think I would rather have 120hz checkerboard over 60hz full frame as the latter would probably give me a tremendous headache. I remember using shutter glasses years ago on a CRT @ around 60hz with plenty of eyestrain/headache as a result.


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BlackShark wrote:
it sounds like the sensio format that we've been able to see in Avatar the game
I thought Sensio format is just another variation of side-by-side with qunicunx sampling, like the RealD format. Do you have any screenshots to post?


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The Sensio format does appear to be side-by-side checkerboard:

Attachment:
Avatar_SENSIO.jpg


Attachment:
Avatar_SENSIO2.jpg


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Fri Feb 19, 2010 7:28 pm
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Neo42 wrote:
I would rather have 120hz checkerboard over 60hz full frame
Both have 60 Hz per eye; the eyestrain was due to the some properties of CRT displays, which do not apply to fixed-pixel displays with passive backlight or pulse-width modulation of brightness.

cybereality wrote:
The Sensio format does appear to be side-by-side checkerboard
Well, judging by the HUD, it appears that Sensio uses even/even or odd/odd quincunx sampling, and RealD uses even/odd or odd/even (explanation here). Who wants to file a patent application for a top-bottom format with vertical subsamping and quincunx sampling? :)


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Bastian I think you would have to draw a 1 pixel diagnal line, not horizontal to get only one eye to see it (like only the black squares on a checkerboard). One benfeit of checkerboard is that it uses less processing power than full res 3d. To be perfectly honest 95% of the time I can't tell the tv is only half res per eye. Like others have said, only thin lines and small text give problems. I watched Avatar in a theatre and did not notice any differences between my half res setup and this dual projector, polarized setup.

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Sun Feb 21, 2010 2:52 pm
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but is it easier to read text as checkerboard format compared to horizontal interlaced format?
just thought it being diagonal would have a different effect on viewing/reading text on screen... :?:
cause horizontal interlaced is really hard for me to read text.

cheers

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Sun Feb 21, 2010 4:17 pm
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I am not getting this 'half the pixels are invisible' idea that people keep talking about. With checkerboard technique there is no information removed, each eye receives the same data but across two frames spaced 1/120th of a second apart.

EDIT: My Mitsu C9 series DLP allegedly has 3 DarkChip4 DMDs which are supposedly natively 1080p panels, which effectively would give this display an advantage of not losing resolution while wobulating for 3D.


Sun Feb 21, 2010 7:58 pm
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Neo42 wrote:
With checkerboard technique there is no information removed, each eye receives the same data but across two frames spaced 1/120th of a second apart
No. Each view is half-resolution (quincunx sampled) video at 60 Hz, not 120 Hz; the resulting frame alternative stereo stream is 120 Hz.

Quote:
give this display an advantage of not losing resolution while wobulating for 3D
Horizontal wobulation is unrelated to frame sequential stereo; the DMD is capable of native 120 Hz.

Check Explain checkerboard and interlaced 3D pls

shonofear wrote:
but is it easier to read text as checkerboard format compared to horizontal interlaced format?
Yes, it should be easier.

Side-by-side checkerboard format is even better, because both left and right views can be sampled at the same positions (as in Sensio and probably RealD), which should improve readability of text placed at screen-depth.


Mon Feb 22, 2010 2:29 am
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shonofear wrote:
but is it easier to read text as checkerboard format compared to horizontal interlaced format?
Yes, it should be easier.

Side-by-side checkerboard format is even better, because both left and right views can be sampled at the same positions (as in Sensio and probably RealD), which should improve readability of text placed at screen-depth.[/quote]

Soo...
Question then, maybe be silly but would it be possible to use my simple wired X3D shutter glasses with say the TRIDEF checkerboard output mode and somehow get it to work and be in sync on a regular CRT monitor or a 85Hz DLP projector?

Just looking for a alternate interlaced option where I can actually read text (pageflip not option atm)

Thank you your intelligence,

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Mon Feb 22, 2010 2:32 pm
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shonofear wrote:
X3D shutter glasses with say the TRIDEF checkerboard output mode and somehow get it to work and be in sync on a regular CRT monitor or a 85Hz DLP projector?
No, you won't see any stereo. The trick is to decode the 60 Hz checkerboard video at the display/projector and convert it to frame-sequential 120 Hz; it can't work without the support on the display side.


Mon Feb 22, 2010 3:11 pm
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mmm, I see.
Thanks anyway,

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Mon Feb 22, 2010 4:19 pm
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DmitryKo wrote:
No, you won't see any stereo. The trick is to decode the 60 Hz checkerboard video at the display/projector and convert it to frame-sequential 120 Hz; it can't work without the support on the display side.


New to the forum..... lots of background with audio and video formats, etc, but trying to decipher the whole situation with the 3D formats, etc..... as I'd LOVE to A) upgrade from my current TV, and B) get in on 3D. (for the record, I've got a PS3, so I'm hoping to use that to drive the 3D display that I eventually buy).

So, is the checkerboard format indeed at 60Hz? If so is that a 1080i@60Hz? or 1080P@60Hz? Bandwidth-wise, 1080i@60Hz = 1080p@30Hz = Best single eye HD quality (i.e. full resolution). If the checkboard is being transferred at 1080i@60Hz, then it would be the same amount of data as non-stereo video, therefore each eye woudl be getting 1/2 of the resolution (which is what I understand is the case from reading this thread). If it's being transferred as 1080P@60Hz, that's double the bandwidth of full-resolution non-stereo video, in which case both eyes should be able to get full-resolution @ 30fps (which none of the broadcast or BD HD formats use more than 24/30fps, right? (I know technically there's 720P@60Hz, but seriously, why hasn't 720P gone away yet?))

Either way, why would 120Hz be required? As a side question: Why are the folks who make these standards stop screwing around and just straight to full-frame, full-resolution 3D? Encode 2 separate 1080P streams (interleaved onto the media for easy reading), and deliver those in sequential format for the display to , uh, simply display. I'm blown away at the notion that intelligence needs to be built-in to the display. IMHO, the display should have NO part in interpreting any video format, etc. It should simply take a stream of bits and display them. Otherwise, now you have to worry about what "formats" your TV supports in addition to your media players, etc...... Geez....

GC

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Thu Apr 15, 2010 8:49 pm
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GoldChain wrote:
is that a 1080i@60Hz? or 1080P@60Hz?
If it's being transferred as 1080P@60Hz, that's double the bandwidth of full-resolution non-stereo video, in which case both eyes should be able to get full-resolution @ 30fps)
Either way, why would 120Hz be required?

It's a 1080p60 signal, which contains a stereo picture in each video frame, encoded in a checkerboard pattern. So it has the same bandwidth as 1080p60 full-resolution mono signal, but contains two half-resolution 60 Hz pictures per each eye, or 120 Hz in total.

Quote:
Why are the folks who make these standards stop screwing around and just straight to full-frame, full-resolution 3D? Encode 2 separate 1080P streams (interleaved onto the media for easy reading), and deliver those in sequential format for the display to , uh, simply display.
IMHO, the display should have NO part in interpreting any video format, etc. It should simply take a stream of bits and display them.

As I said here, you are confusing video compression formats with display link formats.

On the Blu-ray 3D media, the steroscopic movies are encoded with a Multiview Video Coding extension which basically stores a L stream and the difference between two L/R video streams. This is slightly more efficient that just coding two independent L/R video streams, one for each eye (typically 25% less bitrate). This is a device-independent full-resolution format.

The video display link format depents on the display technology used by the stereo 3D display, this is why the player has to encode the video stream to an uncompressed format that is supported by a particular device. That includes checkerboard for DLP displays, "frame packing" top-bottom format for 120 Hz LCD/LED TVs and plasma displays, line interleaved for certain computer monitors, frame alternative format for 120 Hz computer monitors, etc.

A special case are TV broadcasting formats which do not use MVC and involve half-resolution compression formats with top/bottom and side-by-side frame arrangement, which use 1080i60 video signal to fit withing the bandwidth limits of legacy broadcasting platforms. Technically, the set-top-box should be able to upscale them to standard full-resolution formats, however recent HDMI 3D spec includes them as native video link formats, for whatever reasons.


Last edited by DmitryKo on Tue Apr 20, 2010 9:06 am, edited 1 time in total.



Tue Apr 20, 2010 6:13 am
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Good stuff DmitryKo.

I want to be clear, for sake of discussion. I'm aware of the conceptual differences between compression codecs and media transmission (display link).

Encoded Media
\/ \/ \/ \/
Player reads media and decodes encoded video into a "raw" (uncompressed) video stream
\/ \/ \/ \/
Player take raw video stream and puts into another "format" that the display can handle
\/ \/ \/ \/
Formatted display stream is then transmitted via specific interface type (HDMI, component, etc) to display
\/ \/ \/ \/
Display take video signal/stream in and displays it

This is probably an oversimplification of the process, but pretty close. In the case of 3D, the display is doing more than simply displaying the data. It's buffering and showing the same "frame" of video multiple times (i.e. if it's doing a 3:2 pulldown or displaying stereo content, it's alternating views).

My point was, and it's more of a gripe of the path the manufacturers have chosen, IMHO, I want a "dumb" display: feed it pixels, and it displays them. In other words, there should be a single stream formatting that ALL displays that are 120Hz should be able to accept in order to handle stereo video (i.e. page-flipped or top-bottom frame packed, etc... it doesn't really matter, but everyone should just settle on ONE so that ANY player will work with ANY display).

IMHO, the manufacturers are making this way too complicated for no reason. Putting wifi, etc into TVs is just insane. Let the display be a dumb display and have the "smart" device drive it. That way you're not locked into the limitations of the hardware of the display (i.e. if you have a TV with wifi so you can watch YouTube or Hulu, but then they change the video format they play, it may not work on your TV anymore...... let your multifunction PC/Gaming console handle the heavy lifting, and make the display just WORK).

GC

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Tue Apr 20, 2010 8:24 am
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