An Accurate IFS-Based Image Enlargement Method using Line Process

This paper proposes an effective image enlargement method based on an iterated function system (IFS), which is traditionally used for image coding. The IFS can reconstruct an image of a different size from the coding target image´s. Based on this property, some methods enlarging images have been proposed by using the IFS. However, the images enlarged by the traditional methods suffer from block noise and edge discontinuity in the boundary between neighboring range blocks, which are units of the process in the IFS. The reasons for the problems of the traditional methods are that they use non-overlapping range blocks and do not consider edge continuity in the boundary between the neighboring range blocks. Therefore, the proposed method allows selection of overlapping range blocks in order to avoid the block noise. Further, the proposed method introduces a line process, which is used for edge detection, into the enlargement procedure. The edges obtained by using the line process can retain the edge continuity. Therefore, the images enlarged by the proposed method retain the edge continuity. Consequently, an accurate image enlargement can be achieved.