公开(公告)号：US08019788B1

公开(公告)日：2011-09-13

申请号：US10261162

申请日：2002-09-30

申请人： Michael B. Carter ,  Brett Harper ,  Jeff Trom

发明人： Michael B. Carter ,  Brett Harper ,  Jeff Trom

IPC分类号： G06F17/30

CPC分类号： G06F17/30153 ,  H03M7/30

摘要： The size of lightweight JT data files containing CAD data is reduced by employing lossy compression where acceptable for portions of the CAD data, such as 3D geometry data. Dictionary-based lossless compression for the remaining portions is augmented by exploiting common repeated structures for some portions, such as precise Brep data, and compressing separate but similar data, such as all metadata for a given part and all scene graph data, together as a single block. The compressed data is then written in separate, uniquely identified data segments indexed in a table of contents, allowing quick access to any data segment for streaming.

摘要翻译： 包含CAD数据的轻量级JT数据文件的大小通过使用有损压缩来减少，如CAD数据的部分（如3D几何数据）可接受。 通过利用一些部分的常见重复结构（例如精确的Brep数据）和压缩单独但类似的数据（例如给定部分的所有元数据和所有场景图数据），一起作为一个部分来增加其余部分的基于词典的无损压缩 单块。 然后将压缩数据写入分离的唯一标识的数据段，以内容表格索引，允许快速访问任何数据段进行流式传输。