Stereoscopic display is to render two pictures corresponding to and different from the left and right eyes respectively by using a certain algorithm according to the binocular imaging law of human beings, and then make the left and right eyes see the corresponding images respectively according to a certain display output method, so as to make the user have the function of stereoscopic depth vision. This technology enhances the Display Effects of 3D Scene and further enhances the user experience of 3D products. At present, the most popular 3D film technology in film technology is the practical application of stereoscopic display.

Stereo mode

At present, there are three popular stereo display technologies, namely Anaglyphic, active stereo and passive stereo. The following describes the implementation principles, advantages and disadvantages of these three modes.

• Anaglyphic Technology

  The display displays hundreds of millions of colors by combining the three colors of red, green and blue, wherein the mixed color of blue and green is cyan, which is complementary to red. Anaglyphic filters out the blue and green in the left eye picture and the red in the right eye picture, and the viewer uses a pair of two-color glasses. The left eye can only see the left eye image, the right eye can only see the right eye image, and the different images seen by the two eyes are overlapped in the brain to present a 3D stereoscopic effect.

  The advantage of this

  stereo technology is that it has no special requirements for computer hardware, especially the red-blue glasses (filter lenses) can be manufactured by users themselves, and the manufacturing cost is low. The disadvantage is that this mode will cause the loss of color information, which may cause discomfort to the observer.

• Active Stereo Technology

  In the active stereo mode, the driver will render the images of the left eye and the right eye alternately. For example, if the first frame is the image of the left eye, the next frame will be the image of the right eye, and the image of the left eye will be rendered in the next frame. The viewer wears a pair of shutter glasses, which is different from the mechanical shutter of the camera. It uses liquid crystal technology to switch the picture, so the glasses are also called liquid crystal shutter glasses. The shutter glasses are synchronized with the display card and the monitor in a wired or wireless manner; when a left-eye image is displayed on the monitor, the glasses open the shutter of the left lens and close the shutter of the right lens at the same time; and when a right-eye image is displayed on the monitor, the glasses open the shutter of the right lens and close the shutter of the left lens at the same time, In this way, the invisible image of one eye will be retained by the brain as the image of the previous picture according to the visual temporary storage effect, and anyone wearing the shutter type stereoscopic glasses within the coverage of the wireless signal can watch the stereoscopic image.

  Active stereo requires that the left and right lenses of stereo shutter glasses must be synchronized with the corresponding projection image signal, and at the same time, they must have a high refresh rate of stereo display to achieve satisfactory stereo effect. The advantages of this stereo technology are low cost, good stereo immersion, and seamless switching between plane images and stereo images, but its disadvantages are low stereo brightness and easy eye fatigue. However, these shortcomings can be remedied by hardware. For example, using a high-brightness projector for active stereoscopic display can overcome the disadvantage of low image brightness. At the same time, eye fatigue is caused by the flicker of the image. Using a screen with a refresh rate of more than 120Hz can enable the human eye to enjoy a coherent and non-flickering 3D picture. Therefore, the active shutter stereo technology is also widely used now, and is respected and adopted by many manufacturers.

• Passive Stereo Technology

  Passive stereo, also known as polarized stereo. This mode mainly uses the principle of light polarization, because the transmission direction of light is arbitrary angle, polarization technology is to use polarizers to interfere with the transmission direction of light, so that light can be transmitted at a certain angle according to a certain rule, viewers must wear corresponding polarized glasses, each eye only receives the light wave image of the corresponding angle and direction. O as to produce the effect that the left eye and the right eye separately see different images and produce stereo. This mode is generally used by cinemas to show 3D movies.

  The advantage of

  passive stereo technology is that the image does not flicker, the viewer will not be tired, and the field of view is wide. The disadvantage is that it needs to use a special curtain, the optical adjustment process is more complex, and it also needs to prevent astigmatism and so on, so the cost is very high.

Parallax mode

Currently, SuperMap Realspace supports both negative and positive disparity modes. In the negative parallax mode, the objects in the scene are imaged in front of the display screen, giving the viewer the feeling that the scene is displayed outside the screen, giving the viewer a strong three-dimensional feeling.

In the orthoscopic mode, the objects in the scene are imaged behind the display screen, giving the viewer the feeling that the scene is inside the screen, and the obvious depth of field effect can be felt.