Contour Lines Based Image Compression

• Main Authors: Chen, LiChiang, 陳立強
• Other Authors: Chen, Weiming
• Format: Others
• Language: zh-TW
• Published: 2011
• Online Access: http://ndltd.ncl.edu.tw/handle/94889416193962316173

碩士 === 國立宜蘭大學 === 資訊工程研究所碩士班 === 99 === With the progress of science and technology, there is much larger amount of information to be accessed and for transmission in the fast development of internet and multimedia nowadays. Image file is one of the most popular information types nowadays. So it is important to compress the data stream to much smaller size for quick transmission and processing. The popular standard for static image compression is JPEG. Recently, JPEG2000 is proposed to promote the disadvantages of JPEG. For dynamic images (videos), MPEG is the most popular file type using H.264 standard. A novel image compression method using the contour line of different gray levels is proposed in this paper. The method we proposed uses the difference of luminance in spatial domain to form a luminance contour line map, and then we encode the contour line by chain code. After the process of chain code, we compress the chain code data to binary stream by entropy coding. In opposite, the decoding steps are to return the entropy code to chain code, decode the chain code to contour line map and then fill with the gray levels by interpolation method. Finally, the bit rate and PSNR result of the compressed image using contour line method would be compared with the well-known JPEG and JPEG 2000.