基于小波变换的非渐进网格压缩

Non-progressive Mesh Compression Based on Wavelet Transform

为了取得较好的三角形网格压缩性能 ,提出了一种基于小波变换的三角形网格非渐进压缩方法。该压缩方法先利用重新网格化来去除大部分连接信息 ,然后利用小波变换的强去相关能力来压缩几何信息。在进行重新网格化和小波变换后 ,再按一个确定的次序将所有的小波系数扫描为一个序列 ,然后对其做量化和算术编码。另外 ,对重新网格化得到的自适应半正规采样模式 ,还设计了一种自适应细分信息编码算法 ,以便使解码端知道每一个小波系数应该放置在哪一个顶点上。实验表明 ,用该压缩方法对由三维扫描仪获取的复杂网格进行压缩 ,取得了比Edgebreaker方法明显要好的率失真性能 ;10比特量化时 ,压缩倍数在 2 0 0倍左右 ,为 Edgebreaker方法的

A non-progressive triangle mesh compression method based on wavelet transform is proposed in this paper. It uses remeshing to remove most of the connectivity information, then uses wavelet transform to compress the geometry information by taking advantage of its strong decorrelation power. After remeshing and wavelet transform, all wavelet coefficients are scanned in a determined way to form a sequence, then quantized and arithmetic encoded. For the adaptive semi-regular sampling pattern obtained by remeshing, in order for the decoder to know at which vertex each wavelet coefficient locates, an adaptive subdivision information coding algorithm is also designed. Experimental results show that the proposed method has achieved better rate-distortion performance than the well-known Edgebreaker method, and the compression ratio is about 200:1 for complex meshes acquired by 3D scanner under 10 bits quantization, which is more than 2 times of that of Edgebreaker method.