Speckle noise reduction in ultrasound images using SRAD and guided filter

Ultrasound imaging devices are more secure and real-time than other medical diagnosis devices such as X-ray, CT, and MRI. However, due to speckle noise, it exhibits lower resolution and image quality than other than medical diagnostic devices. Therefore, it is difficult to diagnose lesions using ultrasound images due to this noise. In this paper, we propose an algorithm using speckle reducing anisotropic diffusion (SRAD) and a guided filter for speckle noise reduction and edge preservation. First, speckle, which is multiplicative noise, is removed by using SRAD. The remaining noise in the filtered image is converted to additive noise using logarithmic transformation. The additional noise remaining in the filtered image is further removed using a guided filter. Finally, the noise-free image obtained using exponential transform. Experimental results show that the proposed algorithm exhibits an excellent speckle noise reduction and edge preservation performance than the conventional filtering techniques.