3D Ear Shape Matching Using Joint α-Entropy

In this article, we investigate the use of joint α-entropy for 3D ear matching by incorporating local shape feature of 3D ears into the joint α-entropy. First, we extract a sufficient number of key points from the 3D ear point cloud, and fit the neighborhood of each key point to a single-value quadric surface on product parameter regions. Second, we define the local shape feature vector of each key point as the sampling depth set on the parametric node of the quadric surface. Third, for every pair of gallery ear and probe ear, we construct the Minimum Spanning Tree (MST) on their matched key points. Finally, we minimize the total edge weight of MST to estimate its joint α-entropy—the smaller the entropy is, the more similar the ear pair is. We present several examples to demonstrate the advantages of our algorithm, including low time complexity, high recognition rate and high robustness. Furthermore, we demonstrate, for the first time in computer graphics, the classical information theory of joint α-entropy is used to deal with 3D ear shape recognition.