用单张黑白感光片拍摄及再现彩色立体图象

本文提出一种新的记录和再现彩色立体图象的方法。这种方法是将一枚三色光栅安装在照相机的片门处,并让它与黑白感光片密接,先对彩色景物作第一次拍摄,然后相机光轴绕景物主视点转θ°角(θ角满足一定条件),对彩色景物作第二次拍摄,第一次和第二次拍摄时,镜头前分别加品色滤色片和青色滤色片,经二次曝光后将彩色立体图象编码记录在一张黑白感光片上,经冲洗得黑白编码片。     

线性三色采样叶形光栅的制作和应用

用新颖的线性三色采样中形光栅，可以在单色胶片上一步记录彩色图像，这种记录和再现过程不仅操作方便，仪器简单，经济，而且避免了色串扰，莫尔（Ｍｏｉｒｅ）条纹与分辨率的损失，消除了互调制，大大提高了光能利用率，本文给出了用计算机制作叶形光栅的方法，讨论了用这种光栅编码彩色图像的原理及其在全息照相和光学信息处理等其它方面潜在的应用。     

真彩色体视全息图

用三色光栅照相机拍摄景物的两张视差照片，然后用单色激光器经二次曝光全息记录制成一张真彩色体视全息图，在普通白炽灯照明下可再现真彩色体视全息像.该方法制作过程更简单，减少了散斑噪音，消除了彩色全息像的色差，得到的全息像清晰明亮，色彩真实，立体感强.     

θ调制空间伪彩色编码

正1主要内容θ调制是阿贝成像原理的应用:对图像中不同待编色部分赋予不同取向的光栅,制成光栅片.用白光照射该光栅片,在频谱面上得到多列方向不同但0级重合的彩色频谱.如果在频谱面上放置空间滤波器,让不同方向的衍射斑分别透过不同的颜色,就能在像面上得到彩色像.这是利用不同方向的光栅对图像频谱进行调制,因此称为θ调制法.又因为它将图像的不同部位"编"上了不同的颜色,故又称空间伪彩色编码.     

彩色组合编码条纹光栅轮廓术

研究了一种新的编码光栅投影三维轮廓术。其中投影光栅利用彩色空间红、绿、蓝三基色相互独立的特性,用彩色条纹对光栅进行编码,以白色条纹为起始位,后接红、绿、蓝（R、G、B）三种颜色的条纺组成一组。改变红、绿、蓝的排列顺序可使各组有不同的编码。根据排列组合原理,红、绿、蓝三色可有6种不同的排列方式。经过编码处理的光栅在保证测量精度不变的前提下,加大了高度测量的范围。由于每条纹只采用0和255两个状态,因此具有较强的抗干扰能力。测量的精度主要取决于图像的分辨率。     

基于彩色光栅投影的快速三维测量方法

 针对条纹投影术提取物体高度信息的问题,提出了一种新的基于彩色光栅投影的三维测量方法。对选取G分量为255,R,B分量各取0或255而组成的青、白、黄、绿四色遵循格雷码原理进行编码,然后将G分量作正弦调制形成投影光栅投向被测物体。提取采集到的光栅变形图中G分量,利用傅里叶变换方法得到其初始相位;同时对采集到图像中的R,B分量作阈值迭代分割而G分量自动赋值为255,综合三分量信息得到条纹颜色信息进而获取条纹的周期信息,从而展开相位。全过程仅需投影一幅彩色光栅图就能完成三维测量,实验结果表明该算法易于实现,在测量实时性和精确性上表现良好。     

彩色全息图的计算机产生和数字再现

提出了一种基于色彩合成以及菲涅尔衍射原理,用计算机产生全息图并用数字方法再现彩色全息图的方法。该方法的第一步是将物体的彩色RGB图像分离为三基色强度图,再利用博奇编码的方法制成修正离轴参考光分色计算机全息图;第二步是分别对分色全息图在频域进行调制以实现用原参考光真实再现原始物光波。通过滤波消除零级衍射及共轭像的影响,获得了所需要的实像并提高了像质。提供的实验是选用一幅RGB图像作为原始物体,给出了用博奇编码法制成的全息图以及最后经色彩合成获得的再现像。结果表明,该方法能使各分色全息图的再现像准确重合,解决了在色彩合成时容易出现的色串扰问题。     

一种针对彩色物体的光栅投影三维测量方法

针对传统彩色编码光栅三维轮廓术中光栅易受到物体表面彩色纹理的干扰,从而造成编码条纹颜色误判和相位误差增大这一问题,提出一种基于互补彩色光栅的三维测量方法,给出了理论分析、光栅设计原理、补偿算法与实验分析。对图像进行初步的解耦校正后,通过预先设计的光栅互补特性,依据彩色响应模型求取物体表面逐点的反射率,并对红绿蓝(RGB)三通道反射率的不平衡进行补偿,消除物体表面彩色纹理的干扰,改善光栅的正弦性。以补偿后的图像来指导彩色编码条纹的分割解码并用傅里叶变换法提取出包裹相位,依据解码结果指导相位展开,继而完成整个三维测量过程。实验证明该方法对彩色纹理的补偿准确有效,降低了彩色纹理对测量的影响。     

全息透镜用于彩色胶片全息高密度存储

本文提出一种利用全息透镜实现彩色胶片全息高密度存储的方法。用红、绿、蓝三基色激光分别记录三个焦距相同的全息透镜,用三个全息透镜依次用三基色波长记录胶片的傅氏全息图,用原参考光照明再现,可合成彩色像。     

利用三色光栅实现彩色图像相减

本文提出了一种彩色图像相减的新方法.该方法利用互相错动半个周期的两组三色光栅,在黑白底片上分别对待处理的两幅图像进行一次编码记录,然后在白光处理器上对黑白编码片进行彩色译码,即可实现彩色图像的强度相减,文中讨论了三色光栅实时生成和两组三色光栅条纹自动错动半个周期的方法,并给出了实验结果。     

用三色光栅和黑白感光胶片作彩色摄影术的研究与进展

报道南开大学现代光学研究所白光信息处理课题组近十几年在将白光光学信息处理用于黑白胶片作彩色摄影的研究中，各阶段所取得的技术进展，以期社会予以评论和指导。     

A novel 3D deformation measurement method under optical microscope for micro-scale bulge-test

A micro-scale 3D deformation measurement method combined with optical microscope is proposed in this paper. The method is based on gratings and phase shifting algorithm. By recording the grating images before and after deformation from two symmetrical angles and calculating the phases of the grating patterns, the 3D deformation field of the specimen can be extracted from the phases of the grating patterns. The proposed method was applied to the micro-scale bulge test. A micro-scale thermal/mechanical coupling bulge-test apparatus matched with the super-depth microscope was exploited. With the gratings fabricated onto the film, the deformed morphology of the bulged film was measured reliably. The experimental results show that the proposed method and the exploited bulge-test apparatus can be used to characterize the thermal/mechanical properties of the films at micro-scale successfully.     

Nonlinear optical properties of composites based on conductive metal-alkanoate liquid crystals

The dynamic holography in new composite materials based on a novel class of metal-alkanoate ionic liquid crystals (ILCs) is studied experimentally and theoretically. The composites are formed as a dielectric dye film covered by lyotropic metal-alkanoate ILC and ionic smectic glasses with doped dye molecules. The dynamic gratings are created by nanosecond pulses of double frequency Nd:YAP laser, the recording demonstrates fast erasure time of residual thermal gratings. The nonlinear optical properties are determined by the resonance nonlinearity in photosensitive centres of ILC. Note, that permanent relief gratings will be formed on a dielectric dye film only as well as in composite cells either with nematic LC or with polymers under action of pulsed laser radiation. Lyotropic ILC layer applied over the dye film provides the dynamic regime of grating recording in composite cells. We found a secondary thermal grating is much smaller, the conductive ILC matrix provides effective heat dissipation and erasure of this thermal grating. A theory of Raman-Nath self-diffraction holography on thin films followed from the wave equation and the nonlinear mechanism of absorption saturation is developed to explain experimental results.     

一种采用面阵彩色CCD及视频信号接口的光谱仪

介绍了一种使用面阵彩色ＣＣＤ 摄像机和体全息光栅设计的小型光谱仪。该光谱仪使用普通模拟视频信号输出格式,经过带有视频输入接口的计算机显示卡采集信号并实现图像信号的数字化,利用面阵彩色ＣＣＤ的二维图像特点采用软件去除背景噪声,在达到使用分辨率和精度要求的前提下降低了对ＣＣＤ 器件性能的要求。从而降低了整机的造价。利用特别设计的局部缩放机构和ＣＣＤ采集的色彩信息实现了对全光谱的频段细分,在有效像素数不变的情况下提高了系统的物理分辨率。     

Holographic grating recorded by He–Ne laser operating at 632.8 nm in polymer film containing push–pull azo dye

Holographic gratings were optically recorded by two beams from a He–Ne laser operating at 632.8 nm in poly (methyl methacrylate) (PMMA) film containing push–pull azo dye. The holographic characteristics of the recorded gratings were dependent on the polarization direction of the recording beams and the relationship between the diffractive signals and the power density of recording beams was investigated. The formation of holographic gratings accompanied by 532 nm (double-frequency of Nd:YAG laser) irradiation was studied in detail. It was found that the effect of 532 nm laser to the holographic grating lay in two aspects. The acceleration effect of 532 nm laser to the formation of holographic grating is predominant when the power density of 532 nm laser is low. While at relatively high power density of 532 nm laser, the erasure is the main factor to the holographic grating. Moreover, the holographic grating was probed by 532 nm laser at low power density and the dependence of the first order diffractive signal on the recording beam power density was also presented.     

Formation of positive and negative anisotropic holographic gratings depending on recording energy in photoreactive liquid crystalline copolymer films

Anisotropic diffractive gratings formed by birefringent molecular alignment are fabricated by a holographic technique using a photo-cross-linkable liquid crystalline copolymer (PLCCP). Depending on the exposure energy used for holographic recording, bright or dark regions of the interference fringe can be chosen for the molecular-aligned region, analogous to positive- and negative-type photoresist processing in photolithography. In conjunction with simultaneously generated surface relief gratings, the anisotropic refractive index modulation inherent in the PLCCP film exhibits different diffraction properties depending on the incident beam polarization. The anisotropic refractive index grating profiles are quantitatively presented for two cases determined by the exposure energy, based on the Fourier analysis of diffractive optics. The selection of different grating formations selected by varying only the exposure energy could provide a strategy for the fabrication of functionalized diffractive optical elements.     

体全息成像系统中非周期体光栅的深度选择性研究

由一束球面波和一束平面波或者两束球面波干涉所形成的体全息光栅,由于其光栅矢量在全息图体积内是随位置的变化而变化的,所以被称为非周期型的体光栅。主要研究了用于体全息三维成像系统的非周期体光栅的深度选择特性。根据叠加的原理,将非周期体光栅看作多个固定周期的基元体光栅的叠加,结合耦合波理论分析非周期体光栅的衍射特性。采用这一方法,利用Matlab软件模拟,研究了两束记录光夹角对所记录的非周期体光栅深度选择性的影响和在两束记录光夹角相同时,球面参考光体全息成像系统及平面参考光体全息成像系统深度选择性的差别,最后在光折变晶体材料中进行非周期型和周期型体光栅的记录和再现,对模拟结果进行了实验验证。     

Three-dimensional profile measurement of small lens using subpixel localization with color grating

In this paper a measurement method of three-dimensional profiles and a reconstruction system using subpixel localization with color gratings projection is described. The system has the effects of identical contrast on gratings for easier identification, switchable picture-in-picture on the display, and adjustable gratings with an adjustment module.The measurement method includes the following: the projection step; image extraction step; image fine-tuning step; subpixel localization processing step; and reconstruction step. A projection apparatus emits a grating towards a small lens under measurement, and forms a grating image on the small lens under measurement. The contrast values of the plurality of grating stripes of the grating image are identical. The grating image and picture-in-picture of a display can be fine-tuned and reconstruct the three-dimensional profiles of the small lens. This method can help improve measurement competence in the reverse engineering industry.     

全息平面变间距光栅位移传感器研究

基于变间距光栅位移传感器的基本原理,研究了高线密度变化率全息平面变间距光栅的制作方法.所作的变间距光栅已应用在变间距光栅位移传感器中,原理样机测试结果表明,系统分辨率可以达到0.05 mm,相对误差可以控制在0.2% FS之内,优于设计指标.