Image Enhancement by Lifting-Based Wavelet Domain E-Median Filter
Sema Koc, Ergun Erçelebi · 2007
In this study, we propose a method based on wavelet domain E-median filter (WDEMF) for the image enhancement. The method is performed by transforming corrupted image into wavelet domain and filtering the image by e-median filter iteratively. One problem of standard median filter is that it tends to alter pixels undisturbed by noise. To overcome this pitfalls in this study we used e-median filter which is a type of modified standard median filter. For image enhancement spatial domain e-median filter can be used iteratively but in this case, encountering root image of median filter at early stage of iterations is an important issue and thus no further improvement on corrupted image is achieved. We overcome the problem with this study. Because WDMF prevents the median filter from encountering the root image at early stage of iterations. To evaluate performance of the proposed method we compare the results of the proposed method with other methods in literature.