一個利用投影不變量的貼圖演算法

• Main Authors: Tsai Ming Chou, 蔡明洲
• Other Authors: Tsorng-Lin Chia
• Format: Others
• Language: zh-TW
• Published: 1999
• Online Access: http://ndltd.ncl.edu.tw/handle/21713458796159736715

碩士 === 中正理工學院 === 電機工程研究所 === 87 === The key point in texture mapping techniques is the geometric transformation between pixels on screen image and texture image. In a perspective projection viewing system, the geometric transformation is a perspective transformation which involves division operations. It takes heavy computational cost for the transformation of pixels in high resolution images. So, many approximative alternatives were proposed to reduce the execution time for the transformation. However, there exists errors in the approximation of transformation. Actually, it is a trade-off problem in correction and efficiency for texture mapping. In this thesis, an invariant property, cross ratio of four collinear points in perspective projective, is adopted to get a fast texture mapping technique. Only two addition operations and one subdivision operation for each pixel are needed to implement the perspective transformation in our method. It ensures the correction of perspective transformation and reduces the computation load. Experimental results have proved the correctness and superiority in our proposed method.