Quality Of Experience Evaluation For Light Field

In recent years,with the rapid development of multimedia technology,the traditional video has been developed to 360 video and free viewpoint video.360 video and free viewpoint video provide more visual information and the sense of immersion compared with the traditional video,which is the development trend of video business.Compared to the three dimensional degree of freedom feature of the 360 video,the six dimensional degree of freedom feature of the free viewpoint video makes the visual experience more flexible and stronger sense of reality.As a kind of important data source of free viewpoint video,light field has been paid more and more attention by researchers.The quality of the light field affects the user experience.The study of the quality evaluation of the light field has the guiding significance to the judgment of the acquisition performance of the light field,the evaluation of the advantages and disadvantages of the compression algorithm and the criterion of the light field rendering algorithm.In this thesis,first,a subjective evaluation method of light field quality with VR equipment is proposed for the existing problems of the subjective quality evaluation lacking completeness.Then,an objective evaluation model which fusing the texture complexity feature and the effective sampling density is proposed to evaluate the light field quality.For now,the subjective evaluation of the light field quality is not comprehensive due to the current light field display equipment.In this thesis,to evaluate the subjective quality of the light field in an effective way,the light field display platform is developed based on the VR display device.The platform display the light field in stereoscopic vision and completely free viewpoint,which enhancing the accuracy of the result of the light field subjective quality.Then,by using the subjective experiment platform,we explore the influence of the angular sampling density to the light field quality.Finally,the light field's subjective quality and the new viewpoint's image quality is compared,to proving the rationality by using the new viewpoint's image quality to evaluate the light field quality.As for the objective quality of the light field,an objective evaluation model of light field quality without considering the scene content and a light field quality evaluation model considering the surface texture complexity and geometric information of are proposed.When not considering the content of the scene,the spatial sampling density,angle sampling density and focal depth of the light field are the three main factors that affect the quality of the light field.In this thesis,the spatial sampling density,angular sampling density and focal depth of the light field are used to fusing the objective evaluation model of light field,which can effectively evaluate the quality of light field.Considering the content of the scene,the texture complexity and geometric information of the scene are the key factors that affect the quality of the light field.Based on the study of the influence of spatial sampling density,angle sampling density and focal depth on the quality of light field,an objective evaluation model of light field quality by using the surface texture complexity and geometric information of the scene and the effective sampling density of light is proposed to evaluate the quality of light field more reasonable and effective.