Radon 变换的时频分布反演[图像重建]。

Time-frequency distribution inversion of the Radon transform [image reconstruction].

机构信息

Dept. of Electr. Eng. and Comput. Sci., Michigan Univ., Ann Arbor, MI.

出版信息

IEEE Trans Image Process. 1993;2(4):539-43. doi: 10.1109/83.242364.

Abstract

In using filtered backprojection to compute the inverse Radon transform, the ramp filter amplifies noise. Spatially invariant noise filters reduce resolution. It is desirable to filter noise where projections have no local high-frequency components. Using the short-time Fourier transform, the authors apply a time-frequency mask filter that zeroes out projections where local signal energy is below a threshold. Results show improvement over reconstructions using spatially invariant smoothing filters.

摘要

在使用滤波反投影计算逆 Radon 变换时，斜坡滤波器会放大噪声。空间不变噪声滤波器会降低分辨率。理想情况下，应在投影没有局部高频分量的地方滤波噪声。作者使用短时傅里叶变换，应用时间-频率掩蔽滤波器，将局部信号能量低于阈值的投影置零。结果表明，与使用空间不变平滑滤波器的重建相比，该方法有所改进。