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在X射线工业CT(ICT)中,射束硬化会导致重建的图像出现伪影,甚至产生变形。为了消除这种影响,提出了一种基于重投影的多项式拟合校正射束硬化的方法。该方法对原始CT图像进行阈值分割二值化,将物体目标区域的像素值设为1;重投影此二值图像以获取X射线贯穿物体的长度集合;利用多项式拟合此长度集合与多色投影间的关系来建立射束硬化校正模型,用该模型对多色投影进行校正。与传统的多项式拟合校正方法相比,该方法不需要楔状模体(用于测量不同厚度下的衰减值,以此来建立射束硬化校正模型)。研究表明,该方法能有效地抑制射束硬化的影响。
In X-Ray Industrial CT (ICT), beam hardening can cause artifacts in the reconstructed image and even distortions. In order to eliminate this kind of influence, a method of correcting beam hardening based on the polynomial fitting of reprojection is proposed. In the method, the original CT image is binarized by threshold segmentation, the pixel value of the target region is set as 1, the binary image is re-projected to obtain the length of the X-ray penetrating object set, the polynomial is used to fit the length set to the polychromatic Projection to establish a beam hardening correction model, the model for multi-color projection correction. Compared with the traditional polynomial fitting and correction method, this method does not need the wedge-shaped mold body (used to measure the attenuation value under different thicknesses, so as to establish the beam hardening correction model). Research shows that this method can effectively restrain the influence of beam hardening.