利用傅立叶变换全息实现图像相减

Image Subtraction Based on Fourier Transform Holography

提出一种利用傅立叶变换全息实现图像相减的方法。该方法采用计算全息相移技术,并应用二次曝光法记录两幅图像的傅立叶变换全息图,由此两幅图像相减的频谱信息便被直接记录下来,然后对所记录全息图进行傅立叶变换,即可输出两幅图像相减的结果。在整个处理过程中可根据输出时再现像场的分离程度,适当调整记录时参考光的照射角度,使图像相减结果达到最佳。该方法避免了频谱干扰和空间滤波带来的高频信息丢失问题,并可实现实时处理。计算机模拟实验验证了该方法的可靠性与可行性。

A new method of image subtraction by Fourier transform holography is proposed. By this method, the Fourier transform hologram is recorded by double-exposure holography and the computer-generated holographic phase shifting is employed in the second exposure. Thus, the spectrum of image subtraction is recorded directly and the result of image subtraction can be obtained on the output plane. The single output can be separated while changing the inclining angle of the reference wave. The improvement of this method is that it can avoid the interference of the spectrum items and the loss of high frequency informationl Finally, the result of image subtraction can be replayed real-timely. Its reliability and feasibility are demonstrated through computer simulation.