Dual-channel phase-shifting interferometry for microscopy with second wavelength assistance

Dual-channel phase-shifting interferometry for simultaneous phase microscopy is presented. Red and blue light beams are used for microscope illumination. A 45 tilted beamsplitter replicates the object and reference waves in red light together with the object wave in blue light into two parallel beams. The two resulting quadrature phase-shifting interferograms in red light and the object waves in blue light are generated in the two channels. The two interferograms are recorded simultaneously by a color charge-coupled device (CCD) camera, and can be separated via RGB components of the recorded color patterns without crosstalk. As a result, the phase of tested specimen can be retrieved. The feasibility of the proposed method is demonstrated by test performed on a microscopic specimen.     

Reflective point-diffraction microscopic interferometer with long-term stability

An on-axis phase-shifting reflective point-diffraction microscopic interferometer for quantitative phase microscopy based on Michelson architecture is proposed.A cube beamsplitter splits the object wave spectrum into two copies within two arms.Reference wave is rebuilt in one arm by low-pass filtering on the object wave frequency spectrum with a pinhole-mask mirror,and interferes with the object wave from the other arm.Polarization phase-shifting is performed and phase imaging on microscale specimens is implemented.The experimental results demonstrate that the proposed scheme has the advantage of long-term stability due to its quasi common-path geometry with full use of laser energy.     

结合视觉注意力机制和图像锐度的无参图像质量评价方法

针对模糊图像的质量评价,提出一种新的无参图像质量评价方法,该方法结合了自底向上的视觉注意力机制和自顶向下的图像锐度评价标准。根据人眼视觉注意力机制模型,分别计算颜色、亮度和方向显著度图像,通过竞争机制得到人眼优先关注的区域; 利用无参图像锐度评价方法分别对优先关注的区域及背景区域进行评价,综合2个区域的评价结果得到最终的图像质量评价指标。利用该方法分别对相向运动过程中所产生的模糊图像和图像质量评价Live数据库中的高斯模糊图像进行了评价,结果表明:针对两类图像的评价结果与主观评价结果的相关系数均较高,其中,针对相向运动模糊图像的主客观评价结果的相关系数达到0.98。该方法能够胜任对模糊图像的客观质量评价。     

利用合成谱在计算全息图中编码多个物体的方法

 提出在迂回位相傅里叶变换计算全息图中利用合成谱记录多个物体的方法。该方法利用多个物体合成的傅里叶频谱,代替传统的迂回位相型计算全息图中的单一频谱,在一幅计算全息图中完成多个物体的编码。再现时多个物体同时再现在同一衍射级的周围,并且再现像的形式可以多种多样。采用液晶空间光调制器(LC SLM)完成计算全息图的光学再现,实验验证了方法的有效性。结果表明：该方法可有效提高计算全息图的信息容量。     

位相相关在大尺寸物体三维重构中的应用

提出了一种对大尺寸物体进行三维重构的方法.将一正弦光栅投影到物体表面,通过摄像机得到有变形条纹的二维子区域强度像.在频域中完成各二维子区域强度像之间的相关,根据输出的相关峰值位置即可得出平移量,通过图像拼接获得有变形条纹的整个物体的二维强度像.运用傅里叶变换轮廓术可得到大尺寸物体的三维型面,给出了实验结果.