Proceedings of the IEEK Conference (대한전자공학회:학술대회논문집)
- 2002.07c
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- Pages.1495-1498
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- 2002
Consideration of Image Quality of Dithered Picture by Constrained Average Method Using Various Probability Distribution Models
- Sato, Mitsuhiro (Graduate School of Engineering, Utsunomiya University) ;
- Hasegawa, Madoka (Faculty of Engineering, Utsunomiya University) ;
- Kato, Shigeo (Faculty of Engineering, Utsunomiya University)
- Published : 2002.07.01
Abstract
The constrained average method is one of dither methods which combines edge emphasis and grayscale rendition to provide legibility of textual region and proper quality of continuous tone region. How-ever, image quality of continuous tone region is insufficient compared to other dither methods, such as ordered dither methods or the error diffusion method. The constrained average method uses a uniform distribution function to decide number of lit pixels related to the average intensity in a picture area. However, actual distribution of continuous tone region is closer to the Laplacian distribution or triangle distribution. In this paper, we introduce various probability distributions and the actual luminance distribution to decide the threshold value of the constrained average method in order to improve image quality of dithered image.
Keywords