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Image Thresholding based on the Entropy Using Variance of the Gray Levels

그레이 레벨의 분산을 이용한 엔트로피에 기반한 영상 임계화

  • Received : 2011.09.08
  • Accepted : 2011.10.15
  • Published : 2011.10.25

Abstract

Entropy measuring the richness in details of the image is generally obtained by using the histogram of gray levels in an image, and has been widely used as an index for thresholding of the image. In this paper, we propose an entropy-based thresholding method, where the entropy is obtained not by the histogram but by the variance of the gray levels, to binalize a given image. The effectiveness of the proposed method is demonstrated by thresholding experiments on nine test images and comparison with conventional two thresholding methods, that is, Otsu method and entropy-based method using the histogram.

영상의 세세한 부분에 대한 표현 정확도를 나타내는 엔트로피는 일반적으로 영상이 가진 그레이 레벨의 도수, 즉, 히스토그램을 바탕으로 얻어지며, 영상의 이진화를 위한 지표로 널리 사용되어 왔다. 본 논문에서는 이러한 영상 이진화를 위한 엔트로피 계산에 있어서 히스토그램이 아닌 그레이 레벨의 분산을 이용한 엔트로피를 바탕으로 그레이 영상을 이진화하는 알고리즘을 제안하고, 9개의 시험 영상에 대한 실험과 기존의 영상 이진화 기법인 오츠 기법 및 히스토그램을 이용한 엔트로피 기반의 임계값 결정법과의 비교 및 검토를 통하여 제안된 기법의 효용성을 보인다.

Keywords

References

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