چکیده (انگلیسی):

Speckle is a random multiplicative noise which obscures the perception and extraction of fine details in
ultrasound images and speckle reduction is necessary to improve the visual quality of ultrasound images for
better diagnosis. This study aims at introducing an algorithm by hybridizing bilateral filter with NeighShrink.
The bilateral filter is applied before decomposition and after reconstruction of the image using discrete wavelet
transform to improve the denoising efficiency and preserve the edge features effectively. The wavelet
thresholding scheme NeighShrink is used for thresholding of wavelet coefficients. The algorithm is tested
with synthetically speckled and real ultrasound images. Quality evaluation metrics such as Peak Signal to
Noise Ratio (PSNR), Edge Preservation Index (EPI) and Correlation Coefficient (CoC) are used to assess
the performance of the proposed method. Experimental results show that the proposed scheme improves the
visual quality of ultrasound images by suppressing the speckle noise while retaining edges.