An Orthogonal Approximate DCT for Fast Image Compression

고속 영상 압축을 위한 근사 이산 코사인 변환

  • Received : 2015.08.17
  • Accepted : 2015.09.24
  • Published : 2015.10.31


For image data the discrete cosine transform (DCT) has comparable energy compaction capability to Karhunen-Loeve transform (KLT) which is optimal. Hence DCT has been widely accepted in various image and video compression standard such as JPEG, MPEG-2, and MPEG-4. Recently some approximate DCT's have been reported, which can be computed much faster than the original DCT because their coefficients are either zero or the power of 2. Although the level of energy compaction is slightly degraded, the approximate DCT's can be utilized in real time implementation of image or visual compression applications. In this paper, an approximate 8-point DCT which contains 17 non-zero power-of-2 coefficients and high energy compaction capability comparable to DCT is proposed. Transform coding experiments with several images show that the proposed transform outperforms the published works.


Approximate DCT;Energy compaction;High speed implementation;Orthogonality of transforms


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