Design of a Filter against Ultrasound Image Noise for Remote Diagnosis.

Noise is an inherent property of medical ultrasound imaging, and it generally tends to reduce the image resolution and contrast, thereby reducing the diagnostic value of this imaging modality. The noise is mainly produced by the imaging device and compression during transmission for remote diagnosis. Some de-noising algorithm must be applied to enhance image quality. This study presents an edge enhancement function, quad-tree partition and a set of morphological filters for reducing the noise in ultrasound images. Specifically, the morphological filters presented use predefined morphological operations, including structuring elements (SE) that include both dilation and erosion. The proposed voting strategy can be used to select the morphological filter for each block to optimize decoded image quality. Image quality can be enhanced by applying the appropriate morphological filter to each block. Simulation results demonstrate that the proposed technique enhances noise image quality compared to unprocessed JPEG2000 and SPIHT output at an equivalent bit-rate accounting for the side-information overhead, in terms of both peak signal to noise ratio (PSNR) and Human Visual System (HVS). [ABSTRACT FROM AUTHOR]