【摘要】 点模型数据往往非常庞大,需要对这些数据高效压缩以方便进行存储和网络传输.提出了一个高效快速的点模型无损压缩算法.首先将点模型表面切分成多个小面块;以每个块为单位,生成最小生成树并按宽度优先顺序对树形结构进行编码,同时沿树形结构预测.最后,将预测值与真实值分解成符号位、指数和尾数3个部分,分别做差并在各自的上下文中用算数编码压缩.算法在压缩时间和压缩率两项指标上超过以往的点模型无损压缩算法.可以作为点模型压缩算法的一个有益补充,用来对精度要求高的工程数据进行压缩.更多还原

【Abstract】 Point-based graphics has become one of the hottest topics in 3D computer graphics recently.Since point-based models are often too large to be stored and transferred in limited hardware and bandwidth easily,it is necessary to design effective compression methods.We propose an efficient and fast lossless geometry compression algorithm for point-based models.Firstly,point-sampled surface is split into many equal sized surface patches.Over the points of each patch,a minimal spanning tree is constructed and encoded in breadth first order.During this process,each point is predicted from its father in the spanning tree.Then both predicted and actual positions are broken into sign,exponent and mantissa,and their corrections are separately compressed by using arithmetic coding in the different contexts.The achieved bit-rate and time usage in our algorithm outperforms the previous lossless compression methods of point-based models.Our algorithm nicely complements those lossy compression algorithms of point-based models,and it can be used under the situation where lossy compression is not preferred.更多还原