The heterogeneous nature of modern communications stems from the need of transmitting digital information through
various types of mediums to a large variety of end-user terminals. In this context, simultaneously providing a scalable
source representation and resilience against transmission errors is of primary importance. MESHGRID, which is part of
the MPEG-4 AFX standard, is a scalable 3D object representation method especially designed to address the
heterogeneous nature of networks and clients in modern communication systems. A MESHGRID object comprises one or
several surface layers attached to and located within a volumetric reference-grid. In this paper we focus on the errorresilience
aspects of MESHGRID and propose a novel approach for scalable error-resilient coding of MESHGRID's
reference-grid. An unequal error protection approach is followed, to acquaint for the different error-sensitivity levels
characterizing the various resolution and quality layers produced by the reference-grid coder. The code rates to be
employed for each layer are determined by solving a joint source and channel coding problem. The L-infinite distortion
metric is employed instead of the classical L-2 norm, typically used in case of images and video. In this context, a novel
fast algorithm for solving the optimization problem is proposed. The proposed approach allows for real-time
implementations. The experimental results demonstrate the benefits brought by error resilient coding of the reference
grid. We conclude that the proposed approach offers resilience against transmission errors while preserving all the
scalability features and animation capabilities that characterize MESHGRID.
MESHGRID is a novel, compact, multi-scalable and animation-friendly 3D object representation method, which is part of MPEG-4, and which resides in the Animation Framework Extensions (AFX) toolset. The paper introduces the novel concept of local error control for arbitrary mesh encoding. In this sense, the paper proposes a new wavelet-based L∞-constrained coding technique for MESHGRID models, generating a fully scalable L∞-oriented bit-stream. The advantages of scalable L∞-oriented coding over L<sub>2</sub> coding are experimentally demonstrated.