New Index Generation Method for Example-Based Super-Resolution using DCT Signs

Abstract

The purpose of this study is to propose a new method for generating indexes for example-based Super-Resolution. Conventional method had a problem that it takes a long time to search for high-frequency component from the database. The proposed method aims to accelerate the database search by generating an index expressing patterns of gray level in the local block from DCT signs. First, the low-resolution input image is expanded using bicubic interpolation. Local blocks are extracted from the enlarged image and the index is generated. The optimal high frequency components for the local block are then searched for from the database using the generated index. The enlarged image is then converted into a high definition image by adding the searched high frequency components to the local blocks. As a result, a high-definition enlarged image can be obtained at faster speeds using the proposed method than with the conventional method. In conclusion, we have demonstrated that the DCT sign can adequately express gray level patterns in local blocks and is effective in speeding up example-based Super-Resolution.