Loupas T, McDicken W N, Anderson T, Allan P L
Department of Medical Physics & Medical Engineering, University of Edinburgh, Royal Infirmary, Scotland, UK.
Ultrasound Med Biol. 1994;20(3):239-49. doi: 10.1016/0301-5629(94)90064-7.
This paper describes a digital image processor for ultrasonic speckle suppression that was explicitly designed to satisfy the requirements of detail preservation, adequate smoothing and real-time operation. The first two of these requirements were addressed by selecting a nonlinear adaptive algorithm, which uses a measure of local homogeneity to adjust the amount of smoothing performed at each point of the scan, and employing a large (9 x 9 pixels) filtering window. Real-time operation was achieved by developing a highly concurrent systolic architecture that allowed the efficient mapping of the algorithm into low-cost high-density hardware. Initial experience, obtained by interfacing the processor to a scanner, suggests that this type of processing is capable of enhancing the visibility of subtle differences in echogenicity while retaining genuine image detail, as judged by the preservation of the small vessels and ducts. In addition to its impact on contrast resolution, this form of real-time speckle suppression should also prove valuable as a preprocessing stage before performing other digital image processing operations that are sensitive to noise, such as segmentation and three-dimensional rendering.
本文介绍了一种用于超声散斑抑制的数字图像处理器，其设计目的明确，旨在满足细节保留、充分平滑和实时操作的要求。通过选择一种非线性自适应算法来满足前两个要求，该算法使用局部均匀性度量来调整扫描各点的平滑量，并采用大尺寸（9×9像素）的滤波窗口。通过开发高度并行的脉动阵列架构实现实时操作，该架构允许将算法高效映射到低成本高密度硬件中。通过将处理器与扫描仪连接获得的初步经验表明，这种类型的处理能够增强回声性细微差异的可见性，同时保留真实的图像细节，这从小血管和导管的保留情况可以判断。除了对对比度分辨率有影响外，这种实时散斑抑制形式作为执行其他对噪声敏感的数字图像处理操作（如分割和三维渲染）之前的预处理阶段也应具有价值。
