Some information is lost in the compression process, but often the loss is imperceptible to the human eye.
一些信息会在压缩过程中丢失，但是这些丢失人眼是察觉不到的。
However, in the compression process of blocking image data, severe boundary artifact will be produced because of boundary extension and coefficient quantification.
但在分块处理过程中，由于小波变换的边界扩展及系数量化等原因会产生较严重的边缘赝像效应。
The results show that the deformation of rheo-casting billet is more uniform than that of the normal casting in the compression process, so the rheo-cast billet can be hot deformed directly.
结果表明： 流变铸造坯料在变形过程中的形变均匀性明显优于普通铸造的， 因此不需预处理即可直接进行塑性成型；
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