Method for acquiring and true light source and repeat light irradiation based on image

Abstract

The invention provides a real light source obtaining and relighting method based on images, belonging to the technical field of computer graphics. The method comprises the following steps that: step 1, a projector is utilized to project a basic light source by use of a light ray scanning method, so as to establish the corresponding relation between light rays of the basic light source and light rays reflected from an object surface; step 2, a homography matrix is utilized to establish the point-to-point corresponding relation between a visual angle of a camera and a visual angle image of the projector, and under the irradiation of the basic light source and a real light source, the camera respectively collects photos of a diffuse reflection plane with homogeneous materials, so as to establish the corresponding relation between the real light source and the basic light source; and step 3, basal images which are obtained in the step 1 and respectively correspond to the light rays are multiplied by the corresponding relation between the real light source and the basic light source, which is obtained in the step 2, and all images are superposed so as to obtain a result of relighting. The method utilizes a projector-camera system to realize the relighting of the real light source, and simplifies the collection of the real light source.

Description

technical field [0001] The invention relates to a re-illumination method in the field of optical technology, in particular to an image-based real light source acquisition and re-illumination method. Background technique [0002] Re-lighting is a rendering method used in computer graphics and computer vision to calculate the imaging of objects under new lighting conditions, and the acquisition of real light sources provides the properties of light sources for re-lighting, which is also an important aspect of computer graphics and computer vision. an important field of research. Image-based re-illumination technology is a method of obtaining the reflection function of the object surface by collecting base pictures, and using the reflection function to calculate a new imaging method when new lighting is input. The acquisition of light is to establish the attribute model of the light source by collecting images of the light source, and provide lighting parameters for the subseq...

AI Technical Summary

Problems solved by technology

[0003] After searching the literature of the prior art, it is found that the re-lighting algorithm based on the image is mainly divided into two directions, one is the re-lighting of the far-field light source, such as the University of California, Berkeley School of Creative Technology A series of light stages (lightstage) produced by Paul Debevec and others in the graphics laboratory of the company are used to realize the illumination of far-field light. This technology is generally used for re-illumination of ambient light; the other direction is for near-field light sources. (near-field light source) re-illumination, "Dual Photography" ("Two-way Photography Technology") written by Pradeep Sen and others at Stanford University in 2005, this research based on image-based near-field light re-illumination technology can achieve some artificially specified The simulation of special pattern lighting, but it cannot simulate the lighting of real light sources

[0004] However, the retrieval of relevant technical literature on light source acquisition shows that the existing technology is mainly used in model-based relighting rendering, and cannot be combined with image-based relighting. Therefore, there is no image-based relighting algorithm. A good way to introduce the rendering of real light sources in

Images