基于自动抑制的传感器欠采样CT影像降噪方法

摘要

An auto-restraint-based method for reducing abnormal points of images of sensor under-sampling in CT projection domain is proposed. Decide abnormal points in short-penetration distance which is caused by insufficient sensing and projection data areas has much more different values of noise,so reasonable thresholds is automatically selected according to judged different value point,and carry out filtering,thereby reduce set of empirical value and increase level of auto-restraint noise,moreover statistical distribution is more close to non-stationary Gaussian distribution. Simulation show that the method has a better processing effect for reducing under sampling noise caused by low-dose CT,especially problems of overlarge and too small filtering caused by aging equipment and experience settings.%提出了一种基于自动抑制的传感器欠采样CT投影域奇异值点抑制方法。为因传感器感应不足造成的短穿透距离和异值噪声较多的投影数据区域进行判定，之后依据判断的异值点自动选择合理阈值，并进行滤波，从而减少了经验值设置，提高了程序自动化抑制噪声的程度，并使得图像统计分布更趋于非平稳高斯分布。经过模拟仿真验证得出：该方法对因低剂量CT扫描造成的欠采样噪声，尤其是对设备老化和因经验设置造成的过大过小滤波问题具有很好的处理效果。