【摘要】 基于反演Hilbert变换的Tricomi公式和双曲余弦函数Taylor展开,给出一种反演双曲余弦Hilbert变换(CHT)的数值算法,并应用于单光子发射计算机断层成像.利用Taylor展开将函数的CHT变换表示为其Hilbert变换和由各阶矩组成的修正项.利用Tricomi公式得到一个关于函数各阶矩的线性方程组.通过对方程组的截断,可以求得函数的有限阶矩,并得到函数的近似重建.通过数值实验与精确重建公式进行比较,验证了算法的有效性.更多还原

【Abstract】 Based on Tricomi formula for Hilbert transform and Taylor expansion of cosh-function,a numerical inversion algorithm for coshHilbert transform( CHT) is proposed and applied to single photon emission computed tomography imaging. CHT of a function is represented as its Hilbert transform and a correction term including all of its moments by using Taylor expansion of cosh-function. A linear system about all moments of the function is obtained via Tricomi formula. Finite numbers of moments can be solved by truncating the infinite linear system, and the function can be reconstructed approximately. Numerical simulations are performed to verify the algorithm by comparing with analytical inversion formula.更多还原