Why is checkerboard 3d inferior to standard 3d?

[vrekks]

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.

[shonofear]

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

[Neo42]

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.

[DmitryKo]

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.

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

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.

[shonofear]

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,

[DmitryKo]

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.

[shonofear]

mmm, I see.
Thanks anyway,

[GoldChain]

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

[DmitryKo]

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.

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.

[GoldChain]

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

[DmitryKo]

Unfortunately many legacy requirements preclude from following such a simple path as you describe. The problem is, computer displays and consumer televisions have evolved in very different directions for a very long time, and only recently there have been a strong trend for convergence.

As for 3D formats, 120 Hz frame alternative displays are not the only stereo displays in existence, so there can't be one single "fit it all" format such as top/bottom, "frame packing" or frame alternative (these three are essentially the same from the practical point of view). There are quite a few devices with dual-engine setup, so these are better served by a side-by-side format, and there are quite a few devices built around line-interleaved format... not to mention dual projection setups which require dual video interfaces, which is not even supported by HDMI 3D.


Hopefully VESA DisplayPort 1.2 will someday emerge as the ubiquitous full-resolution stereo interface for both 3D TVs and 3D monitors. I personally look forward to having a 27" 2560x1440 120 Hz monitor, which should only be possible with DisplayPort...

[GoldChain]

Good stuff, man!

I think we're on the same page as far as a future ubiquitous standard. It's funny as we still refer to TVs and computer monitors as if they're separate, which only for the fact we consider them separate could be a single category called "Displays".

That's kind of the point of my original "gripe" was that if a display (PC, TV, whatever) simply accepted a bitstream of video data to display that stream at a given resolution and refresh rate, then you've just removed any role the display would need to play in displaying any content. Then it would simply be the device that streams the content to determine if it's non-3D content, or 3D frame alternate (i.e. at that point there would be no need for any other 3D delivery format, as frame alternate would work great with shutterglasses, etc) then send that stream to the display. Boom - done.

Alas, I realize I can't change history, nor the path displays have taken to get where they are. It seems to me it would be beneficial (not perhaps for manufacturers that was to distinguish their products from competitors) to start fresh with displays and formats so that everyone's on the same page

GC

[tritosine5G]

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.

lol . The amount of wishful thinking there

What do you think of that checkerboard +plasma craze over nvidia forums?

How's it better than 720p + 16x MSAA ? I don't even ....

Btw its very good now nvidia is forced to innovate something for 720p. We can avait their answer to mlaa and for 3d its particulary important.