Algorithms of magnifying/reducing, rotation and border following using segmented block code
Masayuki Okamoto, Nobuo Takahashi, Kouichi Kawata · Systems and Computers in Japan · 1987
Abstract This paper describes algorithms of magnifying/reducing, rotation, and border following for binary document images by using a segmented block code. Document images such as facsimile images are composed of a large number of binary data. Thus it is difficult for a small‐sized conventional computer to process efficiently a whole document image in a pixel‐by‐pixel manner. Our algorithms described herein use segmented block coded data instead of pixel data. In the segmented block coding scheme, blocks which are two‐dimensional contiguous black pixel areas are extracted and coded by their locations and shapes. Since this coding scheme compresses the amount of data required to process and produce the data form which is suitable to deal with by conventional computer, our algorithms using this coded data work efficiently. Also, there is another advantage in that the results of magnifying/reducing or rotation of images are obtained in the form of a segmented block code. This means that we can manage document images in a unified manner.