针对闪光照相图像低信噪比的特点,提出了一种自适应的图像重建算法。该算法以代数法(ART)迭代重建为基础,在迭代重建过程中引入了两个权重矩阵,其中一个矩阵用来控制重建过程中的高频分量以保持重建结果的边界;另一个矩阵控制重建结果的平坦区域以提高重建结果的信噪比。通过在迭代过程中更新这两个矩阵来实现图像的自适应重建。数值模拟结果表明,相对于传统的单准则ART重建算法,该方法具有更好的抗噪能力和边界保持能力。

For the flash radiographic image with low signal-to-noise ratio(SNR),an adaptive image reconstruction algorithm was proposed. Based on the conventional algebraic reconstruction technique(ART) algorithm,two weight matrixes associated with the image were imported to the iterative reconstruction. One was used to control the high frequency of the reconstructed image so as to protect its edge;the other was used to control the low frequency so as to improve the SNR of the reconstructed image. Both matrixes were refreshed when the reconstructed image was iterated. Numerical simulation results show that in comparison with the conventional ART algorithm,the algorithm has stronger abilities of noise removal and edge preservation.