摘要
将傅里叶变换光谱技术与数字全息技术相结合,基于噪声差异性原理,利用不同波长重构图像实现降噪,提出了基于波段优选的加权求和平均算法:分析不同波长重构图像的噪声水平,在给定波长范围内分别选取RGB三分量的中心波长,选择合适的区间半径,使用二值化权重因子来实现波长优选,并将三维块匹配(BM3D)算法与加权求和平均算法相结合,以进一步降低噪声。以光学密码系统的解密过程为例,分析降噪效果。结果表明,当RGB三分量中心波长分别为621、549、449 nm,区间半径为26,BM3D算法中噪声水平参数sigma为3时,降噪效果最优,此时降噪图像与原始彩色图像真值之间的彩色峰值信噪比(C-PSNR)为91.11 dB,所提算法在优选波段的基础上有效地降低了噪声,为彩色全息重构图像降噪提供了新思路。
Objective As high-resolution image sensors and computer technology develop,significant applications for holography have emerged in the fields of three-dimensional imaging and display,optical information processing,and intelligent optical computing.However,numerous challenges remain unresolved in both digital holography and computational holography.During the recording process of digital holography,as a kind of multiplicative noise,speckle noise becomes a prominent problem and its removal is more challenging than that of additive noise,drastically compromising the quality of the reconstructed image.Consequently,noise reduction in holograms and reconstructed images is of particular urgency.Current noise reduction methods are primarily categorized into two categories:optical-based methods and digital-based methods.In the optical-based methods,one limitation involves the cumbersome recording process of multiple holograms with speckle diversity by multiple mechanical motions,which could lower the system stability.In the digital-based methods,complex algorithm commonly reaches better noise reduction effects.However,the cost of increased processing time may impede the real-time capability of the system.Therefore,an integrated approach combining optical and digital methods can maximize noise reduction while maintaining a focus on speed.Therefore,we combine Fourier transform spectroscopy technology and digital holography technology to gain speckle diversity holograms.Then,utilizing the noise difference analysis of decrypted images at several wavelengths,we propose a weighted summation average(WSA)noise reduction method,in combination with the block matching 3D(BM3D)algorithm.As a result,the optimized effect of noise reduction can be achieved.Methods First,we calculate the normalized monochromatic peak signal-to-noise ratio(M-PSNR)between the reconstructed images and take the original images as a representation of the noise intensity level of the reconstructed images,which are used as an initial weighting factor.Subsequent
作者
贺佳雪
娄树理
林超
He Jiaxue;Lou Shuli;Lin Chao(School of Physics and Electronic Information,Yantai University,Yantai 264005,Shandong,China;Aviation Operations and Service Institute,Naval Aviation University,Yantai 264000,Shandong,China)
出处
《光学学报》
EI
CAS
CSCD
北大核心
2024年第9期31-44,共14页
Acta Optica Sinica
基金
国家自然科学基金(62005318)。
关键词
傅里叶光学
光谱全息技术
图像降噪
加权求和平均算法
三维块匹配算法
Fourier optics
spectral holography
image noise reduction
weighted summation averaging algorithm
block matching 3D(BM3D)algorithm
