The Design And Realization Of Seamless Multi-projector Display System

With the rapid development of digital city construction, high resolution and largescreen display system is widely used in traffic management, process control and otherpanoramic view field. Multi-projector display technique uses several traditional projectorsto display a whole image, which can extended display resolution effectively and becomeas a large screen display technology development trend. The quality of the mosaicedimage determines the progress of the technology.Two key problems need to be solved in the multi-projector display technique,geometric calibration and color correction. In addition, edge-blending plays an importantrole in the brightness processing of overlapping area. The existing technology ofgeometric calibration and color correction is mainly based on camera, which is commonlyused to adjust the output of a projector. Geometric calibration technology has achievedvery good results with the help of camera. However, to some certain degree gamut rangeis compressed because the color information precision captured by the camera is not highenough. As a result, the mosaiced image color information is not rich.Based on the study of domestic and foreign related technology, we propose a manualgeometric calibration method based on software, compared with the existing methods, ourmethod has strong adaptability and good stability. We research the color correctiontechnology further and obtain accurate color information by using spectrophotometer. Ourexperiment has highly improved the consistency and richness of the mosaiced imagecolor. The main work in this thesis is divided into the following three keys:(1)Geometric Calibration: We propose a manual geometric calibration method basedon software and design a manual geometry correction system. Our system has realizedthe geometry correction of single and multi-projector.(2)Color Correction: We use spectrophotometer to obtain accurate color informationand established the color space conversion model from RGB to XYZ by using polynomialregression method. In order to realize accurate color matching of different projectors inXYZ space, we use the triangle interpolation and iteration method to realize the color search from XYZ to RGB space.(3)Edge Blending: The highlighted part of the overlap region is eliminated by usingsuitable fusion function. The existing methods generally use the empirical gamma value ingamma correction. The experiment obtained precise projector gamma value, through theestablishment of gamma correction look-up table to realize the gamma correction of fusionzone.