Speckle Noise Reduction in Ultrasound Images by Using Hybrid DWT Technique

Abstract

ULTRASOUND (US) imaging application in medicine and other fields is enormous. It has several advantages over other medical imaging modalities. The use of ultrasound in diagnosis is well established because of its noninvasive nature, portable, accurate, low cost imaging modality, capability of forming real time imaging and continuing improvement in image quality. However the usefulness of ultrasound imaging is degraded by the presence of signal dependant noise know as speckle nose. It is well-known that speckle is a multiplicative noise that degrades the visual evaluation in ultrasound imaging decrease the human ability to identify pathological from normal tissue because it depends on the structure of the image tissue and various imaging parameters .The main purpose for speckle reduction in medical ultrasound imaging to improve the image into keep in mind that certain speckle contains diagnostic information and should be retained. The objective of this thesis is to give an overview about types of speckle reduction techniques in ultrasound imaging and to present a new technique of speckle reduction. A new speckle reduction method of medical ultrasound images was proposed: the discrete wavelet transforms (DWT). It has been found that quality evaluation metrics the proposed methods performed better than all other methods while the structural details and results preserved edges and features in a better way than other despeckling filters