A Low Power VLSI Architecture for Mesh-based Video Motion Tracking
This paper proposes a low-power very large-scale integration (VLSI) architecture for motion tracking. It uses a hierarchical adaptive structured mesh that generates a content-based video representation. The proposed mesh is a coarse-to-fine hierarchical two-dimensional mesh that is formed by recursive triangulation of the initial coarse mesh geometry. The structured mesh offers a significant reduction in the number of bits that describe the mesh topology. The motion of the mesh nodes represents the deformation of the video object. The architecture consists of motion estimation and motion compensation units. The motion estimation architecture generates a progressive mesh code and the motion vectors of the mesh nodes. It reduces the power consumption, uses a simpler approach for mesh construction, approximates the mesh nodes motion vector by using the three step search algorithm and uses a parallel motion estimation core to evaluate the mesh nodes motion vectors. Moreover, it maximizes the lifetime of the internal buffers. The motion compensation architecture uses a multiplication-free algorithm for affine transformation, which significantly reduces the complexity of the motion compensation architecture. Moreover, using pipelined affine units contributes to the power savings. The video motion compensation architecture processes a reference frame, mesh nodes and motion vectors to predict a video frame. It implements parallel threads in which each thread implements a pipelined chain of scalable affine units. This motion compensation algorithm allows the use of one simple warping unit to map a hierarchical structure. The affine unit warps the texture of a patch at any level of hierarchical mesh independently. The processor uses a memory serialization unit, which interfaces the memory to the parallel units. The architecture has been prototyped using top-down low-power design methodology. The performance analysis shows that this processor can be used in online object-based video applications such as in MPEG and VRML.
Wael Badawy and Magdy Bayoumi, “A Low Power VLSI Architecture for Mesh-based Video Motion Tracking,” The IEEE Transactions on Circuits and Systems II, Vol. 49, July 2002, pp. 488-504.
A VLSI Architecture for Video Object Motion Estimation Using a 2D Hierarchical Mesh Model
This paper proposes a novel hierarchical mesh-based video object model and a motion estimation architecture that generates a content-based video object representation. The 2D mesh-based video object is represented using two layers: an alpha plane and a texture. The alpha plane consists of two layers: (1) a mesh layer and (2) a binary layer that defines the object boundary. The texture defines the object’s colors. A new hierarchical adaptive structured mesh represents the mesh layer. The proposed mesh is a coarse-to-fine hierarchical 2D mesh that is formed by recursive triangulation of the initial coarse mesh geometry. The proposed technique reduces the mesh code size and captures the mesh dynamics. The proposed motion estimation architecture generates a progressive mesh code and the motion vectors of the mesh nodes. The performance analysis for the proposed video object representation and the proposed motion estimation architecture shows that they are suitable for very low bit rate online mobile applications and the motion estimation architecture can be used as a building block for MPEG4 codec.
Wael Badawy, “A VLSI Architecture for Video Object Motion Estimation Using a 2D Hierarchical Mesh Model,” Microprocessors and Microsystems, Vol. 27, No. 3, April 2003, pp 131 – 140, invited.