A Hybrid Technique for Speckle Noise Reduction In ultrasound images

Abstract

In the field of biomedical imaging, Ultrasound is an incontestable vital tool for diagnosis, it provides in non-invasive manner the internal structure of the body to detect eventually diseases or abnormalities tissues. These images are obtained with a simple linear or sector scan US probe, which show a granular appearance called speckle. . Unfortunately, the presence of speckle noise affects edges and fine details which limit the contrast resolution and make diagnostic more difficult. The removal of this noise is still a challenging one in medical image processing and analysis, because of multiplicative nature. Most of speckle reduction techniques have been studied by researchers; however, there is no comprehensive method that takes all the constraints into consideration.Filtering is one of the common methods which are used to reduce the speckle noises. The objectives of this work was to carry out a comparative evaluation of despeckle filtering based on image quality evaluation metrics, moreover a hybrid technique has been proposed which works by passing an image through wavelet based Multiresolutional analysis and combined filtering techniques with SRAD filter (Speckle Reduction Anisotropic Diffusion) and hybrid median filters, for more improvement the total variation filter has been applied on the reconstructed image to get a final image. The quality of the enhanced images will be evaluated in terms of filter assessment parameters namely Signal-to-Noise Ratio (SNR), Peak Signal-to-Noise Ratio (PSNR), and Root Mean Square Error (RMSE) as well as in term of visual quality of the images for each tested filter. The computational results are presented in the form of filtered images, statistical tables and diagrams. Based on the statistical measures and visual quality of the filtered images the proposed method performed well over other conventional techniques.