关键词: 文物, 纹理映射, 双二次多项式, 拟合系数, 双向纹理函数（BTF）, PTM模型

Abstract:

Aiming at the unrealistic and inaccurate problems of 3D reconstruction object texture, a cultural-relic texture mapping algorithm based on Polynomial Texture Maps（PTM） model is proposed. This algorithm takes advantage of the polynomial color dependence and adopts a biquadratic polynomial that characterizes color and brightness dependence coefficient for storing texel data. Thereby, the surface texture of the object can be reconstructed under varying lighting conditions. In addition, aiming at the problems of reconstruct image texture bluring, ghosting and object detail texture missing, which are result from diffuse reflection anomaly?of the original acquired image, the uneven distribution of luminance information, and the inaccurate reconstruction fitting coefficient of the original PTM model, a PTM algorithm for improving the basis function of polynomial and optimizing the fitting coefficient and an optimization method for PTM image acquisition equipment are proposed. Finally, the experiment proves that the authenticity and accuracy of the reconstructed object texture are effectively improved.

Key words: artifacts, texture mapping, biquadratic polynomial, fitting coefficient, Bidirectional Texture Function（BTF）, Polynomial Texture Maps（PTM） model