Method for calculating lighting parameters and carrying out relighting rendering based on image and model

Abstract

The invention discloses a method for calculating lighting parameters and carrying out relighting rendering based on an image and a model, comprising the following steps: (1) using a 3D point cloud model of a scene to calculate the normal vector of each 3D point; (2) calculating the light source position and direction vector of an image according to the coordinates and the normal vector of each 3D point and the pixel value of the image; (3) by supposing that the lighting model of the image is a Phong model, calculating the parameters of an energy function in the model based on the light source information obtained in the previous step; (4) calculating the shadow and highlight areas of the image; and (5) giving a target RGB image to be rendered, fusing and rendering the scene and lighting information of the original image into the target image, and outputting a final rendering result. By using the method, the relighting process of special-effects production in film and television post-production is simplified, the relighting rendering result can be output quickly, and a user can preliminarily judge whether an input image is applicable to later virtual-real combination. The problem that rework is caused as the lens and post-production inconsistency cannot be found in the existing film and television production process is solved.

Description

technical field [0001] The present invention relates to a re-illumination rendering method, in particular to a method for calculating image illumination parameters and performing re-illumination rendering based on a single RGB image and a three-dimensional point cloud model of an image scene. Background technique [0002] Image-based relighting technology (IBRL) has a lot of research results in the field of graphics and image processing, but due to the influence of complex lighting changes, such as the formation of shadows and the mutual interference of multiple light sources, most of the existing research It is limited to relighting according to the ambient light after the 3D model is known or modeled on the 3D model. The existing image-based re-illumination methods are generally divided into three categories in terms of implementation principles, methods based on birefringence functions, basis functions and plenoptic functions. [0003] Compositing techniques in games and...

AI Technical Summary

Problems solved by technology

However, due to the complexity of the calculation of plenoptic functions, there are relatively few studies on re-illumination using plenoptic functions.

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