摘要
For eliminating the zero-order image in digital holography, a new method using the differential of the hologram intensity instead of the hologram itself for numerical reconstruction is proposed. This method is based on digital image processing. By analyzing the spatial spectrum of the off-axis digital hologram, it theoretically proves that the zero-order image can be effectively eliminated by differential before reconstruction. Then, the detected hologram is processed in the program with differential and reconstruction. Both the theoretical analysis and digital reconstruction results show that it can effectively eliminate the large bright spot in the center of the reconstructed image caused by the zero-order image, improve the image quality significantly, and render a better contrast of the reconstructed image. This method is very simple and convenient due to no superfluous optical elements and requiring only one time record.
为了去除数字全息零级像,提出了用离散全息图的微分强度替代全息图本身用于数字重建的新方法.该方法基于数字图像处理技术,通过对离轴数字全息图的空间频谱分析,首先理论上证明数字全息图的强度经过微分后再重建,可有效去除零级像;然后将实验采集到的全息图在程序中先微分再重建.理论分析和数字重建结果都表明,该方法可以有效地去除数字全息零级像在重建图像中心产生的大亮斑,从而显著提高重建图像的质量,使得重建像具有良好的对比度,且不需要其他辅助设备或多次全息记录,实验操作简单,方便快捷.
基金
The Natural Science Foundation of Jiangsu Province (No.BK2006102)
the National Natural Science Foundation of China(No.10772086)
