Digital Matting and Compositing System Based on Shape from Shading (SFS) under Variant Lighting and Shading Environment

• Main Authors: Liang-Chuan Wang, 王亮川
• Other Authors: I-Cheng Chang
• Format: Others
• Language: en_US
• Published: 2008
• Online Access: http://ndltd.ncl.edu.tw/handle/25z26n

碩士 === 國立東華大學 === 資訊工程學系 === 96 === Matting and Compositing is originally used to deal with special effects composition problem in the movie technology, that is, in the boundary regions of object and background intersection, if it is a more complicated texture, such as tree, hair, water, smoke and some properties of light transmittance etc., the refraction of light will make pixel to receive the lights that come from object and background simultaneously, and this proportion of mix is called “Alpha Value”. Thus, in order to lower the complexity of background, it costs much money to build “Blue Screen” in a film studio, and then take object in there, but, it might generate the background-colored image in the boundary regions, and the color of object must differ from blue screen, it also can’t be used to natural image. Besides, it is very easy to obtain digital image, how to save hardware costs and to apply to nature life, obtaining a more real and beautiful compositing image, it is still our objective. In this paper, we propose a new 3D based digital matting and compositing system, that use digital matting to deal with the object which boundary has property of light transmittance, and use automatic white balancing to deal with light source condition consistency between the object and new background. In addition, use Shape from Shading (SFS) to reconstruct 3D depth information of object, and relight according to light source direction of new background to deal with shading condition consistency between the object and new background, these will make compositing image more harmonious between the object and new background, also make compositing image more real and natural, and it is not easy to be seen through by eyes.