How to create a 3D image

[TechyGuy]

There are three dimensions that in many ways gives life to the world we live in. Vertical, horizontal and depth. It is the latter that separates our world from the Mario and Luigi's. When we are in the Nintendo world famous, it is worth to mention that most games today actually takes place in three, not two dimensions. The screen you are playing on has only two dimensions, namely the horizontal and vertical lines. Nevertheless, one has for several years been able to see the depth of the screens that physically contains only the other two dimensions.

When we for a little over a month ago, tested a monitor from Zalman, we got a good idea of how far 3D technology has come for the commercial market. We went a little into how Zalman had done this, but with this guide, we want to give you a little deeper insight into this technology. We should not talk about the screen to the Zalman, but discuss and explain the various technologies that are found for the commercial market when it comes to images in three dimensions.

[TechyGuy]

The eye that sees

It is the fact that we have two eyes, and not one that gives us the ability to perceive depth in a good way. Although only the eyes are located, with a few centimeters distance in between, see the objects with different distance and from different angles. There is no talk about a great distance, but the difference is large to the eyes will be able to understand it. That we can see anything from two angles, allows one saw see a side of the object that the other saw no see.

The theory is that to create a three-dimensional image, you have to let the flat screen, which has two dimensions, to create two images - one for each eye. This is where the physical limitations arises. Before you is only a display, with a panel. How should one then be able to make double-up with photos, when you only have resources to create an image?

There are several technologies that have seen the light of day for commercial use, and we shall now speak of the four technologies that have not been broke in huge short time. What the military or other high-tech agencies have to rough with, we will not discuss.

[TechyGuy]

Virtual Reality Helmet

The direct way to create three-dimensional images is by using so-called vrh devices - Virtual Reality Helmet.

Virtual Reality Helmet

These helmets contain two separate screens, one for each eye. They show their own image of the same object from different angles. Your brain interprets as if the two images and creates depth. Such helmets often use helicopter pilots in rescue and not least in the military, to see better during bad weather.

Unless you have a very wide wallet, you will not access such helmets with a larger resolution than 640 x 480 pixels. The reason for this quickly becomes expensive because it is difficult to produce small screens that simultaneously has a high resolution.

The obvious negative point with these devices is the size. They are heavy, large and not at least see the blood harry if you play Half Life 2 with such a design on the head. Let us go back to regular screens, and see what we can do with them.

[TechyGuy]

Two colors, two photos

To create three-dimensional images, you need more than just the screen. Naturally it is not as simple as dividing the screen in the middle. The screen should now produce two images, and you need an external component, so that your eyes only see the image they see - and not both. The latter is solved simply by using any special glasses.

The method that is best known among the people, is the type you see above. A portion of the image is red, and part of the picture is blue. The two colors have a little distance in between them, and using the glasses separate the colors so that each eye only sees one of the colors. Let us go a little deeper.

Thus, the screen produces an image that resembles the image at the top of this page, and you are wearing glasses that resembles the above. The red glass will allow the left eye does not see red color in photos. The blue glass does not allow you to see the blue tones in the right eye like.

Since the two colors have different distances in relation to each other on the image, this creates a three dimensional effect.

This technology has several disadvantages. In the first place, it is impossible to see such a picture in the long run, without using glasses. The biggest drawback is that the color reproduction is minimal. The picture is dark, and much marked by blue and red. It is, in other words, goodbye to the full-scaled HD, so let's take a look at the next technique.

[TechyGuy]

Polarization

An improvement of this blue-red-technology is the polarization. Here you will get much more color, but it only works on LCD screens. It must also be some modifications to.

It is precisely this technique Zalman used in the screen we mentioned on the first post. The graphic below is taken from the product page at the same screen, and describes the principle well.

LCD monitors generate the image using liquid crystals. These crystals give out polarized light. A filter in such a 3D display segments the image in the horizontal lines - one for each row of pixels. The principle that you need an image for each eye also applies here. Inside the screen must be placed a special matrix which ensures that light wave are circular, not linear as they usually are. Every other horizontal line of pixels will rotate a different way what the rest do. When light wave is circular, you have greater freedom to move your head in relation to the screen than what you would have with linear light wave.

Now come the glasses in the picture again, but this time both have the same color jars. Glasses is a polarization filter, where the glass to the right eye is rotated 90 degrees relative to the left. Since the jars are different angles, release various forms of light through.

Now the screen is divided into horizontal lines for every other pixel, and you are wearing spectacles polarity.

Software

This technology requires support from more than just the screen, it also has some software to. This software supports only Windows Vista, and it is Nvidia which currently has the best support.

Take a look at the top frame in the top picture on this page. Software must divide each image in the horizontal lines, and pushing the little from each other before they again brought together to a somewhat twisted picture. Again, the distance between the two images that are combined that makes you want to understand the three-dimensional effect.

The result

When you are wearing glasses, the right eye only see every other horizontal row of pixels, while the left eye will see the rest. Glasses do with other words that the eye only sees the part of the image it is meant to see, so the brain takes care of the interpretation.

This technology allows you to see a full color spectrum with relatively high brightness. Real feeling of depth is very large, and you really look at objects sticking out from the screen. There are however some disadvantages.

Since the image is split up into horizontal lines for every other pixel, the vertical resolution in half. A screen with a resolution of 1920 x 1080 pixels, therefore, only 1920 x 540 pixels in the actual resolution. Nevertheless, the resolution is significantly higher than what you get with the Helmets, we mentioned earlier, not to mention that the price is much lower.

Display card with this technology must also generate twice as many images from different angles, they also put together again. This ensures that the number of frames per second (FPS) will be more than halved. Another problem occurs if you look at the picture with a vertical angle. When will the image be divided into horizontal bands, and the experience disappears.

To form the 3D display, as mentioned, requires a separate matrix inside the screen. You can not create such 3D images without a special screen - such as Zalman contributions.

[TechyGuy]

Mechanical solution

The last method we shall talk about is a technique that was fast and hard on the market, but died just as quickly. Some webshops have had these in their range, and the price was at around some thousands. It only works for moving pictures.

The principle was that the screen displays the full images, an image for each eye. The images that are intended for right and left eye switch regularly. Do you see a movie with 20 frames per second, this technology will halve this number by showing each other image for the left eye, and the rest of the right eye. This means that 10 of the images are oriented toward the left eye while the ten other is towards the right.

To separate the images from each other using glasses with the help of mechanics and electronics is blocking half of the images. When your screen displays the image that is intended for the right eye, blocking glasses the left eye total. When the screen displays the image that is intended for the left eye, blocked the right eye.

This technology requires that the monitor and the glasses have a very accurate synchronized. If the closing does not occur exactly at the same time as the change of image, the image is diffuse. If you take advantage of an LCD, it is also important that the response time is so good that the two images are not provided in each other.

The obvious problem here is vision heads and the number of photos in seconds. If the number of frames per second is already relatively low, and then halved it, you will perceive the movie or game that choppy. If the image patch is increased, it may again be a problem with vision heads and monitor's response time.

[TechyGuy]

Summary

We have now taken you through the four technologies that let you see images in three dimensions, through displays containing only two physical dimensions.

The first one has to think about, is that it is the eye that sees and the mind interprets. One must therefore get the eye to see something, that the brain interprets as depth again even if the depth is not there.

The direct way of doing this is to create an image for each eye. With a Virtual Reality helmet has a screen for each eye. These are unfortunately very large, heavy, and they often have low resolution before the price rises enormously.

Blue-red glasses are very popular among the people. The images you see has a blue and a red part. You use glasses with the same colors so that for example the right eye does not see blue, while the left does not see red. The problem is that the color reproduction is very low.

Polarization of the image will be a much better option. Here you get full color, and the simulated effect is very good. The technique works for a short clear by splitting the screen into horizontal lines, and you use glasses that only every other row for each eye.

Another technique that is said about it, go on a mechanical principle. The display shows different images several times per second, where every image is intended for the right eye while the rest goes in the left eye. To separate the images from each other, you have your glasses that block all light on the right and left eye in the reverse order that the display generating images. This technology quickly died out, and was never a great success.