An effective and flexible image enhancement algorithm in compressed domain

作者：Kuo Chung Ming^*; Yang Nai Chung; Liu Chih Shan; Tseng Pi Yun; Chang Chi Kao

来源：Multimedia Tools and Applications, 2016, 75(2): 1177-1200.

DOI：10.1007/s11042-014-2363-x

• Discrete cosines transform (DCT)
• Compressed domain
• Multi-enhancement factors
• Image enhancement

Images with JPEG format using discrete cosine transform (DCT) is selected for most popular compression standards. Enhancement in the compressed domain offers two major advantages, including low computational complexity and storage space. However, the compression is achieved by block-based transform; therefore, it is hard to enhance image globally. In this paper, the main issue is to develop a global enhancement method that effectively reduces the introduced blocking artifacts and achieves excellent visual quality of enhancement. We propose a combined DCT matrix representation, which consists of 8n x 8n pixel arrays, to enhance the global information on images for removing block artifacts in compressed-domain. In addition, we propose the multi-enhancement factors based on spatial frequency for image enhancement in compressed domain. From the simulation results, the proposed method achieves not only excellent improvement for image enhancement but also reducing the blocking artifacts significantly.

• 出版日期2016-1