Data Hiding based Compression Mechanism for 3D Models

Different compression methods [2] such as progressive meshes and single refinement mesh compression exist for mesh representation for 3D models and improving them is a challenge. This paper is a step in this direction, where we show that data hiding methods can be used to significantly improve the compression achieved for such methods. 3D meshes are made up of connectivity (edge set E) and geometric (vertices set V) information. The data hiding method should provide a very high embedding rate in order to achieve a desirable compression ratio. This can be modeled mathematically, given ‘V ’ points or vertices in 3D space; for a given compression ratio we use ‘K ’ points and hide rest of the connectivity and geometric information inside it. These points are termed as the encoding points and the encoded information is termed is the compressed information. Hiding capacity (K) ≥ Size of (V – K) + Size of (E) (1) In order to do so, we need to make sure that ‘K ’ provides a hiding capacity, which is large enough to encode this data (see equation 1). Since data hiding methods result in distortions, it is imperative to minimize these distortions as well