提出一种全息模拟再现像的三维重构方法,可以模拟再现得到三维再现像.计算机模拟再现许多幅在不同深度位置的二维光强分布;利用灰度级变化的聚焦度评价方法,通过寻找最大聚焦度值,确定再现三维像各像点的深度信息.实验证明,该方法能实现模拟再现像的三维重构,使数字全息术有希望成为一种全新的三维面形检测技术.再现像三维重构的实现可以更客观地对全息图进行像质评价,并验证计算机制全息术算法的正确性.
Numerical reconstruction is the focus problem of the digital holography. However,the techniques that have been discussed can only obtain the 2-D light field distribution. In this article, a method about 3-D rebuilding based on numerical reconstruction of the hologram is proposed,by which the genuine 3-D image can be numerically reconstructed. A number of 2-D light field intensity distributions of the digital hologram are numerically reconstructed on the different depth planes. Then, the focus measure evaluation of the gray level variance is applied. By finding the maximum focus measure, decide on the depth information of each image point. The experiment confirms that the method can materialize the 3-D rebuilding of the reconstruction image, that is, 3-D profile information of the object can be obtained by the proposed approach. So digital holography can be a very promising technology for non-destruction 3-D shape measure. In addition, 3-D reconstruction can provide an effective way to the image evaluation of the hologram and validating the correctness of the CGH algorithm.