The fourth chapter discusses the huffman coding method , anticipating coding method and wavelet transform coding method used in this paper 第四章讨论了课题中采用的霍夫曼编码、预测编码和小波变换编码的理论和方法。
Frequently used major coding methods include predical code , transform code , vectol quantization , wavelet transform code , fractal code , ect 常见的主要编码方法有预测编码、变换编码、矢量量化编码、小波编码、分形编码等等。
But there is obvious " block noise " in this transform coding method useing dct . and it is difficult to improve the compression performance 然而利用dct作为主要技术的变换编码方法存在着明显的方块效应,而且进一步提高压缩性能很困难。
But be careful . as our example demonstrates , it is very easy to introduce bugs by transforming code in this way , whether it is altered by human hands or by software 但是请注意:就象我们的示例所演示的那样,以这种方式转换代码时很容易引入错误,不论是由人工还是由软件来完成这种转换。
In the second part : the emphasis of this part lies in discussing subband coding , wavelet transform coding and fractal coding , whose coding functions are better than the coding of having dct as the core 因此本文第二部分重点讨论了编码性能要优于离散余弦编码的子带编码、小波变换编码和分形编码。
Transform coding is a type of data compression for "natural" data like audio signals or photographic images. The transformation is typically lossy, resulting in a lower quality copy of the original input.