De-speckling 2D-Discrete Wavelet Transform with Hard Threshold Stage | ||
| AL-Rafidain Journal of Computer Sciences and Mathematics | ||
| Article 8, Volume 9, Issue 1, June 2012, Pages 101-112 PDF (651.79 K) | ||
| Document Type: Research Paper | ||
| DOI: 10.33899/csmj.2012.163674 | ||
| Authors | ||
| Dhafer F. Hasan1; Maha A. Abdul-Jabar1; Zahraa T. Abed Al-Mokhtar2 | ||
| 1College Medicine University of Mosul | ||
| 2College of Engineering University of Mosul | ||
| Abstract | ||
| In this work, a new method is implemented for removing noise from gray scale image that depends on two-dimensional discrete wavelet transform and Threshold stage (hard threshold). This paper represents the algorithm to remove the speckle noise by using logarithm operation. This operation changes the multiplicative noise to additive noise. So that, the removing operation becomes easier. The Matlab program is used to build the Algorithm and measure the PSNR and other measurement criteria as (NMV, NV, NSD, ENL and PSNR) to study the effect of removing noise from corrupted image. The PSNR reaches to 24dB which is very satisfactory result in the reconstructed image, while the maximum value of ENL is 2.23 * 106, and the minimum value of NMV, NV, NSD which is equal to 6.79, 2.67*10-5, 46* 10-4 respectively gives a smoother and cleaner image. The universal Threshold is applied in high frequency coefficient (i.e. the LH, HL, and HH-sub band of image) to remove the speckle noise and the low frequency coefficient (LL-sub band of image) is still without any change. | ||
| Keywords | ||
| speckle noise; Discrete Wavelet Transform; universal Threshold; logarithmic function | ||
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