Realistic wrinkle generation for 3D face modeling based on automatically extracted curves and improved shape control functions

摘要

Realistic wrinkles are extremely important for enhancing the realism of three-dimensional (3D) virtual face models. This paper proposes an approach for generating realistic wrinkle on a 3D face model based on a face image. It includes image preprocessing, automatically extracting wrinkle curves and generating wrinkles on a 3D surface. For image preprocessing, we use a linear transform method to conduct a grayscale conversion. We then use a transfinite-pixel neighborhood averaging method to reduce the noise, and a high pass filter to sharpen the image. For the automatic extraction of wrinkle curves, an improved Canny edge detector is employed. For wrinkle generation on a 3D surface, a number of novel techniques are employed. Some feature points are firstly defined both on the face image and on the 3D face model. By aligning these feature points, the extracted wrinkle curves are then projected onto the 3D face model. Finally, three shape control functions are used to produce more realistic properties of the 3D wrinkles. They are the proposed cross-section shape control function (CSCF) to determine the crosssection shape and size, the depth attenuation function (DAF) and the width attenuation function (WAF) to control the depth and width amplitude variations of the wrinkles, respectively. For better results, an adaptive subdivision is applied to the predefined influence region to adjust the resolution around the wrinkle mesh. The experiment results of applying this method to individualized 3D human models demonstrate the ability of our method to generate more natural wrinkles.