灰度图像的有损RLE压缩  

LOSSY RUN-LENGTH ENCODING COMPRESSION OF GRAY IMAGES

作　　者：林小竹[1] 万建邦[1] 

机构地区：[1]北京石油化工学院信息工程学院,北京102617

出　　处：《石油化工高等学校学报》2004年第3期89-92,共4页Journal of Petrochemical Universities

摘　　要：行程编码是一种简单有效的数据压缩编码方法 ,在信源编码中属于统计编码无损压缩的范畴。一般的图像数据存在内在的相关性 ,对原始图像数据进行一定变换可将内在相关性提取出来 ,这就为行程编码在图像压缩领域的应用提供了可能。基于对传统行程编码方法的分析可知 ,必须对其进行一定改进才能保证对数据的有效压缩 ,改进后的编码方法可称为简单有损行程编码。图像的内在相关性可通过变换编码加以分析 ,离散余弦变换就是一种较常用的变换编码方法。对原始图像数据进行离散余弦变换和重排 ,可使相关性较好的数据集中起来 ,为利用简单有损行程编码方法创造了条件 ,该编码方法可称为复合有损行程编码方法。通过实例比较分析 ,证明了该方法能对灰度图像进行有效压缩。在可接受的有损范围内 ,获得较好的压缩比。The run-length encoding (RLE) is a concise and effective encoding method for data compression, a lossless compression method, in the field of statistical coding within source coding. Image data commonly contain inherent relevant information, which can be exhibited by transforming the original image data. This makes it possible to compress the image data by run-length encoding method. Based on the analysis of run-length encoding method, it must be improved to ensure effectively compression for data, which is called simple loss RLE method. The inherent relevant images can be analyzed through discrete cosine transform (DCT), which is a usual transform encoding method. Data having good correlation can be gathered through DCT. For differentiation with former method, this method is called complex loss RLE method. It proved to be effective for compression of gray images by comparison and analysis of some examples. Preferable compression ratio could be obtained with an acceptable loss of data.

关 键 词：灰度图像 有损压缩 行程编码 离散余弦变换 

分 类 号：TP317.4[自动化与计算机技术—计算机软件与理论]