Cartoon animation and morphing with wavelet curve descriptor

A new framework for cartoon animation is proposed in this work. By using the wavelet coefficients as the control points, one can manipulate curves so that shape metamorphosis occurs along resolutions as well as spatial locations. We model the motion of a cartoon character with the Lagrangian dynamic equation where the multiscale curve is driven by relevant forces. The spatial and frequency localization property of the multiscale curve model results in a sparse and diagonally dominant representation of the mass and stiffness matrices of the Lagrangian equation and hence the computation can be greatly simplified. To further simplify this model, we consider a model which consists of a decoupled system of ODEs. We then perform an experiment by capturing an image sequence with the locomotion of a walking dog, selecting some key frames, and tracing the positions of limbs between these key frames. The best motion parameters are determined by using the least squares approximation. These extracted parameters are then be used to animate cartoon characters of a similar type of motion. The result shows the proposed curve descriptor with multiscale structure and local control property is promising in cartoon animation applications.