J. Mihalik

Shaping of Geometry of 3D Human Head Model

This paper deals with shaping of the geometry of 3D human head model by the texture model of human faces (TMHF) combined with an algorithm for deforming of the wireframe 3D model Candide. TMHF is represented by the set of eigenfaces, which are obtained by means of the principal component analysis of the training set of completely preprocessed textures of human faces. The algorithm for deforming of 3D model Candide needs its reasonable starting approximation and an update matrix calculated from the training set by manual perturbation of 3D adapted model for single components of the parameter vector. Two approaches of shaping of the geometry of 3D human head model will be presented, by means of which chosen shape units of Candide will be deformed to the human faces inside or outside of the training set.

Convolution implementation with a novel approach of DGHM multiwavelet image transform

Abstract The purpose of this paper is to develop convolution implementation of DGHM (Donovan, Geronimo, Harding, Massopust) multiwavelet image transform using a new approach of ordering wavelet coefficients at the second and higher levels. Firstly, the method of implementation of one-dimensional discrete multiwavelet transform (1D DMWT) for DGHM multiwavelet using discrete convolution and scalar filters is presented. Then, convolution implementation of DGHM multiwavelet image transform by application of 1D DMWT for two dimensions (2D) in a separable way is proposed. Next, the second level of 2D DMWT is performed in three possible ways. The novelty of the proposed implementation is in reordering of L subband wavelet coefficients at the first level into one subimage. The results are evaluated as the energy ratios between the transformed images in L subband at the second level and the input original image. According to the experimental results, the developed implementation of 2D DMWT is approximately 5% more effective in energy compression than the ones most commonly mentioned in the literature. This paper shows a possibility of convolution implementation of 2D DMWT with higher energy compression.

Generation of Knot Net for Calculation of Quadratic Triangular B-spline Surface of Human Head

Generation of Knot Net for Calculation of Quadratic Triangular B-spline Surface of Human Head This paper deals with calculation of the quadratic triangular B-spline surface of the human head for the purpose of its modeling in the standard videocodec MPEG-4 SNHC. In connection with this we propose an algorithm of generation of the knot net and present the results of its application for triangulation of the 3D polygonal model Candide. Then for the model and generated knot net as well as an established distribution of control points we show the results of the calculated quadratic triangular B-spline surface of the human head including its textured version for the texture of the selected avatar.