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http://dx.doi.org/10.7236/JIWIT.2012.12.5.205

Medical Image Enhancement Using an Adaptive Weight and Threshold Values  

Kim, Seung-Jong (Dept. of Computer Science & Information Systems, Hanyang Women's University)
Publication Information
The Journal of the Institute of Internet, Broadcasting and Communication / v.12, no.5, 2012 , pp. 205-211 More about this Journal
Abstract
By using an adaptive threshold and weight based on the wavelet transform and Haar transform, a novel image enhancement algorithm is proposed. First, a medical image was decomposed with wavelet transform and all high-frequency sub-images were decomposed with Haar transform. Secondly, noise in the frequency domain was reduced by the proposed soft-threshold method. Thirdly, high-frequency coefficients were enhanced by the proposed weight values in different sub-images. Then, the enhanced image was obtained through the inverse Haar transform and wavelet transform. But the pixel range of the enhanced image is narrower than a normal image. Lastly, the image's histogram was stretched by nonlinear histogram equalization. Experiments showed that the proposed method can be not only enhance an image's details but can also preserve its edge features effectively.
Keywords
Wavelet and Haar Transform; Threshold; Weight; Nonlinear Histogram Equalization;
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