웨이블릿 변환을 이용한 영상복원의 물결현상 제거 방법

Ringing Artifact Removal in Image Restoration Using Wavelet Transform

  • 윤진영 (중앙대학교 첨단영상대학원) ;
  • 유윤종 (중앙대학교 첨단영상대학원) ;
  • 전신영 (중앙대학교 첨단영상대학원) ;
  • 신정호 (한경대학교 웹정보공학과) ;
  • 백준기 (중앙대학교 첨단영상대학원)
  • Youn, Jin-Young (Dept. of Image Engineering. Graduate School of Advanced Image Science, Multimedia, and Film, Chung-Ang University) ;
  • Yoo, Yoon-Jong (Dept. of Image Engineering. Graduate School of Advanced Image Science, Multimedia, and Film, Chung-Ang University) ;
  • Jun, Sin-Young (Dept. of Image Engineering. Graduate School of Advanced Image Science, Multimedia, and Film, Chung-Ang University) ;
  • Shin, Jeong-Ho (Dept. of Web Information Engineering, Hankyoung National University) ;
  • Paik, Joon-Ki (Dept. of Image Engineering. Graduate School of Advanced Image Science, Multimedia, and Film, Chung-Ang University)
  • 발행 : 2008.11.25

초록

디지털 영상이 멀티미디어의 핵심 매체로 자리를 잡게 되면서 영상의 열화요인을 제거하여 원래의 품질에 가깝게 개선하는 영상 복원기술의 활용분야가 더욱 늘어나고 있다. 그러나 영상복원을 수행할 때 영상의 열화(degradation)가 선형공간불변이라고 가정하기 때문에 주파수영역에서 영상복원을 수행하면 그 결과 에지와 같이 밝기값의 변화가 큰 영역 주변에서 물결현상(ringing)이 나타나는 단점이 있다. 본 논문은 물결현상 제거를 위해 새로운 적응적 후처리 필터링 방법을 제안한다. 제안하는 알고리즘은 웨이블릿 변환을 사용하여 영상을 해석하고 에지 맵을 추출하고 영역을 나누어 에지영역과 물결현상을 검출한 후 이를 쌍방향필터(bilateral filter)를 이용해 제거한다. 실험결과를 통해서 제안하는 방법이 효과적으로 물결현상을 제거하는 동시에 중요한 에지를 보존할 수 있음을 확인할 수 있다.

Digital image find own level core media in multimedia as image restoration technology fields, which remove degradation factor for image enhancement, have been growing. Linear space-invariant image restoration algorithm often introduce ringing artifacts near sharp intensity transition areas. This paper presents a new adaptive post-filtering algorithm for reducing ringing artifact. The proposed method extracts an edge map of the image using wavelet transform Based on the edge information, ringing artifacts are detected, and removed by an adaptive bilateral filter. Experimental results show that the proposed algorithm can efficiently remove ringing artifacts with edge preservation.

키워드

참고문헌

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