cybereality wrote:@Fredz: Well brightness loss is actually less than with the Zalman solution. Even though resolution is halved (like Zalman) you are not wearing polarized glasses. So colors are brighter and more accurate (but not by much).
Ah yes, I incorrectly said that a slanted disposition would enhance brightness, but it's not the case. In fact it will even it out on the whole screen because the black space between subpixels won't be visible only in vertical lines but dispatched equally on the surface of the screen.
cybereality wrote:Ghosting can be reduced by using the monitor in portrait orientation and increasing the duty cycle and/or adding additional barriers. However this causes a massive reduction in image brightness and overall quality so it is not worth it. However in some tests I did get extremely low ghosting, so it is possible.
You can try the technique used in this paper to reduce ghosting :
http://www.evl.uic.edu/files/pdf/Kooima-VR07.pdf" onclick="window.open(this.href);return false;
Basically they use a 3/4 opaque duty cycle and use an interleaving composed of 4 bands : left eye, black guard band, right eye, black guard band. This should effectively reduce the ghosting even if it also lowers brightness, but if they've chosen this method I guess it's because it still gives a better depth perception in the end and that the compromise is more interesting.
cybereality wrote:The moire pattern is actually caused by the camera taking the picture. I did not see anything like that in real life. There was, however, a grainy-ness to the image, but it looks more random than moire.
I can't really tell without actually seeing your screen, but I'd say the grainy-ness you see could be a moiré. Moiré artefacts can take several different forms, with parallax barriers they often produce visible vertical lines. That's one of the reason why many autostereoscopic displays now use slanted parallax barriers instead of vertical ones.
cybereality wrote:Horizontal resolution loss is inevitable with a solution like this, but its not so bad (especially since my "real" 3d solution is also interleaved its not that big a difference).
The slanted setup can also reduce this by mitigating the disparity in both horizontal and vertical resolution instead of only halving the horizontal resolution. That's the second goal besides reduction of the moiré that was pursued by Douglas Winnek when he invented the slanted technique.
cybereality wrote:I did read some white-papers that suggested using diagonal barriers, and the concept seemed interesting. However that would not work with the iz3D driver, and thus be useless for gaming.
Yes, I'm not aware of any driver supporting that at this time, but with the recent video posted about iPont supporting slanted barriers with YouTube 3D the interest may grow. And the implementation is quite straightforward so it wouldn't be very difficult to add it to a stereo driver.
cybereality wrote:However I do have plans to continue this project for a custom application (for example, done in OGRE) and in that case I could experiment with diagonal. I guess I could test in Photoshop first, but its not a priority at the moment.
If you want to try to implement this technique, have a look at this paper that gives a good description of the algorithm (for lenticular screens but easily adaptable to parallax barriers I think) :
http://iss.bu.edu/jkonrad/Publications/ ... A_1999.pdf" onclick="window.open(this.href);return false;
cybereality wrote:However, I still don't quite understand how that helps the situation much. At the end of the day, you are ultimately blocking individual pixels (or sub-pixels) so that comes along with the same problems. Would be interested if you had a link that clearly explained the benefits
There are several benefits to slanted parallax barrier, as I said it reduces the moiré because black spaces between subpixels appear on the whole screen instead of only in vertical lines (picket fence effect).
They also enhance the perceived resolution by distributing it on both horizontal and vertical resolution instead of only the horizontal one.
Another advantage is that you don't need a printer with an exact multiple of the dpi of your screen since by turning your sheet you can make the bars coincide with the pixels.
You are even not forced to make the bars coincide when working with subpixels, you only have to add an offset to your algorithm so it always produces an adequate rendering.
There is also the image flipping effect which causes a noticeable transition between the viewing zones, which is overcomed with slanted installation by producing a smooth transition between views.
In this document it's apparently said that the acuity is better (x1.4) when using sub-pixel-scale line screens instead of pixel-scale ones (ie. the width of a band is less than a pixel), but I'm not sure I understood the text correctly (§4.2 in the last and previous page) :
http://www.evl.uic.edu/files/pdf/Kooima-VR07.pdf" onclick="window.open(this.href);return false;
Also if you've got a webcam you could even add support for eye tracking in order to always be in the sweet spot, I guess you should be able to use FreeTrack to do this.