| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide image compressing and decompressing methods and devices having little block distortion and folding distortion. <P>SOLUTION: This data compressing method for compressing data of input signals that continue in one direction divides data into continuous sections composed of two pieces of data. Next, the method obtains a frequency coefficient of each section area by applying orthogonal transformation to the data in each section area. Then, the method calculates a boundary value predictive AC component in each section area in every other section by using data adjacent to both neighboring sections and makes a residual obtained by subtracting the boundary value predictive AC component from a frequency coefficient of an AC component of a section area be an AC component of each section area in every other section. Then, the method calculates an average value predictive AC component in each section area in every other section by using the frequency coefficient of DC component of both the adjacent section areas and makes a residual obtained by subtracting the average value predictive AC component from the frequency coefficient of an AC component of a section area be an AC component of each section area in every other section. The obtained AC component of each section area is quantized and encoded to obtain compressed data. <P>COPYRIGHT: (C)2009,JPO&INPIT</p> |
