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在 B超三维成像中 ,采用了一种新的基于非线性域值小波包的闪斑 (Speckle)噪声抑制方法来提高成像质量 .首先将一幅原始图像经过预滤波分解为高频噪声图像和低频主体图像两部分 ,然后分别经过多分辨率小波包处理 ,得到一组小波包域的系数 .该系数采用一种软阈值滤波算法处理 ,去除掉其中的噪声并保留下各自的有用信息 .两组分别去噪后的小波包系数经反变换回到时域并相加 ,得到消除了噪声的图像 .该算法的性能在计算机仿真图像上进行了验证 .采用该方法处理了一组水槽中的碗状物体的 B超图像 ,并进行了三维体视化重构 .实验表明 ,这种方法可以有效地抑制超声闪斑噪声并在重构中保留对象的细节特征
In B-dimensional 3D imaging, a new speckle noise suppression method based on nonlinear domain-valued wavelet packet is proposed to improve the image quality.An image is first decomposed into high frequency noise image and Low frequency main body image two parts, and then through multi-resolution wavelet packet processing, get a group of wavelet packet coefficients, the coefficient using a soft threshold filtering algorithm to remove the noise and keep their respective useful information. The denoised wavelet packet coefficients were inverse transformed back to the time domain and added to get the noise-canceled image.The performance of the algorithm was verified on the computer simulation image.This method was used to deal with B-image of bowl-shaped objects and three-dimensional stereoscopic reconstruction.Experiments show that this method can effectively suppress the noise of the ultrasonic flashes and retain the detail features of the object during reconstruction