Research On Distortion Correction Of Head-mounted Display

Head-mounted displays(HMDs)are a new type of display devices,in which image quality of the optical system directly affects the user experience.In addition,with the development of display technology,manufacturing industry,and new materials,the optical system of the HMDs progresses from large and heavy to small and light,and the field of view(FOV)becomes bigger.However,when the volume and weight of the optical system are limited and a larger field of view is desired,designers involve more complex optical elements,and the optical aberration also increases.Especially,optical distortion causes serious geometric deformation in the imaging.Therefore,a suitable method for distortion correction is of great significance for HMDs with large FOV,small volume and light weight.In this paper,based on the research of optical distortion in HMDs,a pre-distortion image generation algorithm is proposed.The distortion of the optical system is compensated by the reverse deformation of the ideal image,to correct the distortion.The method does not require complicated mathematical calculations,and there is no limitation on the distortion shape of the optical system.The calibration process can correct the design distortion of the optical system,and the distortions generated during the manufacturing and assembly processes.Real-time correction can be achieved by creating a pre-distortion pixel mapping lookup table.The article introduces the development of HMDs,and points out the problems encountered in the development of HMDs.Then,the commonly used distortion correction algorithm is introduced and analyzed.Next,a pre-distortion image generation algorithm based on FOV segmentation is proposed,by the coordinate mapping between the original image to the distorted image and the linear deformation of the image.Finally,the optical distortion of the see-through HMD is corrected.Its distortion is controlled within one pixel,and the correction time is less than 0.08 s.Finally,the error analysis of the pre-distortion testing system is carried out,and algorithms are proposed to improve the accuracy of the distortion correction.