傅里叶变换同轴数字全息记录余弦变换谱系数  

Recording of cosine transform spectrum coefficients using fourier transform in-line digital holography

作　　者：郑楚君[1] 窦德召[1] 李榕[1] 常鸿森[1] 

机构地区：[1]华南师范大学物理与电信工程学院,广东广州510631

出　　处：《光电工程》2006年第6期53-56,共4页Opto-Electronic Engineering

基　　金：广东省自然科学基金资助(021089)

摘　　要：余弦变换广泛应用于图像和视频的压缩编码以及模式识别之中。余弦变换为实偶对称的傅里叶变换,把实偶对称物体传送到位于傅里叶变换透镜前焦面的空间光调制器上,采用单色均匀平面激光光波照射,则在后焦面上为光波复振幅分布为实偶对称物体的傅里叶变换,即为物体的余弦变换。由于余弦变换谱系数既有正实数又有负实数,提出了采用傅里叶变换同轴数字全息方法记录余弦变换谱系数,通过把数字全息图减去参考光光强和物光光强而得到余弦变换系数。理论推导和实验结果表明了该方法的可行性,该方法可应用于图像的快速余弦变换。Cosine transform is widely adopted in image, video compression and pattern recognition. Because cosine transform is real-even symmetric Fourier transform, a real-even symmetry object is transmitted to Spatial Light Modulator which is placed at the front focal plane of a Fourier transform lens, the even symmetry of object allows its cosine transform to be obtained at the back focal plane when the Spatial Light Modulator is illuminated by collimated planar laser. Owing to the spectrum coefficient with negative and positive real, recording of cosine transform spectrum coefficients using Fourier transform in-line digital holography is proposed. Intensity of reference wave and object wave are subtracted from the Fourier transform in-line digital hologram to obtain the cosine transform coefficients. The theoretical and experimental results show that the method is feasible, effective and suitable for fast cosine transform in image processing.

关 键 词：数字全息 空间光调制器 余弦变换 光学傅里叶变换 

分 类 号：TB877[一般工业技术—摄影技术]