基于相位拼接的数字全息大视场成像方法研究

Method of digital holography WFOV imaging based on phase stitching

提出了一种利用相位拼接技术以扩大数字全息成像视场的方法。通过平移被测物体,记录物体各子区域的离轴全息图,然后利用菲涅尔再现算法得到部分物体相位像。在此基础上,采用均化误差算法对各子区域的相位像进行拼接,并对拼接相位像进行去倾斜处理,得到无畸变的扩展物体相位像。最后,利用USAF 1951反射型分辨率板对该方法进行实验验证。结果表明该方法能够克服CCD阵列大小对成像视场的限制,在保证成像分辨率的同时,有效扩展了数字全息的成像或测量范围。

A method to enlarge the field-of-view in digital holography imaging based on sub-aperture phase stitching tech-nique is proposed in this paper. The part information of an object is recorded by the off-axis digital holographic interferometer and the part phase image of the object is picked up by means of the Fresnel diffraction algorithm. Then the phase profiles in all the sub-regions are stitched together with the error averaging method,while the tilt of the stitched map are calculated and elimi-nated to obtain the orthoscopic profile of the whole surface. It was validated by the reflective resolution plate USAF 1951. The proposed method breaks away from the limits of the area of the CCD and expands the digital holography imaging field-of-view while the resolution is kept in the same level as that of the traditional methods.