The Design And Implementation Of A Full Dome Film System

Full dome film refers to the use of one or more sets of projectors to project intact continuous pictures on spherical screen. Full dome film can reveal a high resolution and a big angle range of display effect, with a horizontal angle of 360 degrees and the maximum vertical angle more than 200 degrees, which can create a novel visual experience and the audience will feel a strong visual shock and a sense of immersion. In the full dome projection system, because of the different locations of projectors and audience, and probably a system is composed of multiple projectors , the image onto the spherical screen would produce a certain degree of distortion, whether stretched or compressed, which will make a difference on the color of the image, resulting in a great dissimilarity between the projection image and its real image and in turn influences people's visual effect, therefore, 3D geometric calibration and color correction are needed for pictures of different projectors.The system chooses Microsoft Visual C++ 6.0 for the development environment. According to software engineering's method, demand analysis should be carried on first to provide systematic structure as well as the operation process gradually, and to provide the design of the geometric calibration module and color correction module. The geometric calibration module adopts one kind of frame buffer texture mapping technique which is based on the projection sock top in the polar coordinates system to achieve geometric correction. Color correction function consists of both automatic and manual correction function. The automatic one fulfills its function by template matching through choosing two channels which needs correction. The latter one regulates the color in the given channel by adding color reference points in the color correction curved line. It corrects the color in the given channel according to the numerical calculation principle of the cubic spling interpoliation to make the color of the projection image look as possible as the real one.Through the automatic geometry calibration and color correction of the projection images, the projection images of multiple projectors can be correctly Mosaic and projected, its distortion is very small, close to the actual image, achieving a level which can be visual neglected.