Super-Resolution using Discrete Cosine Transform sign as Index of High-Frequency Components

Abstract

The purpose of this research is to propose a new super-resolution method using DCT. The proposed method enlarges a small block in an input image to a large block through DCT. A high-definition image is created by applying this method to the entire low-resolution input image. The enlargement of small blocks is carried out by expanding the DCT coefficient's frequency domain to the same size as that of the large blocks. First, the high-frequency component that is lacking in a small block is searched for from a database. Then, it is added to a small block and restores the high-frequency component. The high frequency component is searched for using a DCT sign index. The database is trained using multiple natural images beforehand. The proposed method made a high-speed search possible by using DCT sign index. From many simulation results, it was found that the proposed method was more effective than the traditional one.