TITLE:
Point Selection for Triangular 2-D Mesh Design Using Adaptive Forward Tracking Algorithm
AUTHORS:
Nastaran Borjian, Rassoul Amirfattahi, Saeed Sadri
KEYWORDS:
Motion Estimation, Optical Flow, Pixel-Based, Block-Based-Region-Based, Mesh-Based, Adap-tive-Forward Tracking, Polygon Approximation, Content-Based Mesh Structure, Triangulation, Affine Compensation, Mesh Refinement.
JOURNAL NAME:
Positioning,
Vol.2 No.1,
February
24,
2011
ABSTRACT: Two-dimensional mesh-based motion tracking preserves neighboring relations (through connectivity of the mesh) and also allows warping transformations between pairs of frames; thus, it effectively eliminates blocking artifacts that are common in motion compensation by block matching. However, available uniform 2-D mesh model enforces connec-tivity everywhere within a frame, which is clearly not suitable across occlusion boundaries. To overcome this limitation, BTBC (background to be covered) detection and MF (model failure) detection algorithms are being used. In this algorithm, connectivity of the mesh elements (patches) across covered and uncovered region boundaries are broken. This is achieved by allowing no node points within the background to be covered and refining the mesh structure within the model failure region at each frame. We modify the occlusion-adaptive, content-based mesh design and forward tracking algorithm used by Yucel Altunbasak for selection of points for triangular 2-D mesh design. Then, we propose a new triangulation procedure for mesh structure and also a new algorithm to justify connectivity of mesh structure after motion vector estimation of the mesh points. The modified content-based mesh is adaptive which eliminates the necessity of transmission of all node locations at each frame.