共查询到19条相似文献,搜索用时 46 毫秒
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为实现在单次成像条件下获取图像的光谱偏振信息,提出了一种基于强度调制的编码孔径测量方法。该方法采用消色差1/4波片、多级相位延迟器和检偏器组成的光谱偏振强度调制模块,将入射光的Stokes参量各元素谱调制到不同的频率上,利用编码孔径和色散棱镜组成的光谱成像系统对该调制光谱进行压缩编码,并通过CCD进行探测。利用TwIST算法重构出经调制的光谱信息,对各个频谱通道进行分离重构出Stokes元素谱。以单一像素点为例,对入射光强度调制、光谱重构及Stokes参量的解调进行了数值模拟。结果表明:该方法可实现对稀疏图像的光谱偏振信息的获取,该过程仅需对图像进行一次测量,因此具备高速获取能力。 相似文献
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分形图像压缩编码是当今图像编码领域研究的热点之一,是一种具有独特优势且极有发展前途的数据压缩技术。本文从分形基本理论出发,对分形图像压缩编码思想、编码方法等进行了综述,并介绍了分形图像压缩编码的一些改进方法。最后,探讨了分形图像压缩编码的发展方向。 相似文献
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为了提高图像盲复原质量,提出了量子比特编码算法。首先在免疫系统中的对量子克隆选择,并且对量子抗体克隆比例控制;然后量子抗体随机赋值,使抗体都以随机概率处于所有可能状态的线性叠加态中,以量子态进行观测,将得到确定的某一个二进制;接着建立图像盲复原重建模型,量子编码卷积算法来填充空洞像素;最后给出了算法流程。实验仿真显示该算法对图像盲复原重建清晰,画质好,全图最大局域误差最小,结构相似度接近于1。 相似文献
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为解决传统色散型高光谱成像仪扫描速度慢和编码孔径光谱成像系统存在部分信息失真或丢失、光谱重构复杂度高等问题,设计了一种基于均匀分布狭缝阵列的光谱成像系统,在编码孔径光谱成像系统的基础上,采用微位移电机控制阵列编码狭缝对成像视场进行微扫描,以实现光谱不混叠成像,在满足一定成像帧频的条件下实现动态场景的无损探测.仿真结果表明:在光谱图像重构质量与单狭缝系统结果一致的前提下,该系统的采集效率提升了 17倍;空间结构相似度和光谱保真度分别是50%压缩采样率编码孔径光谱成像系统的1.8倍和1.17倍,在完成仿真的基础上,搭建实验装置进行了可行性验证. 相似文献
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利用小波变换的3个高频分量之间相关特性,提出了基于球坐标变换的非线性小波变换图像压缩编码的方法,在小波收缩中,采用双曲线收缩处理球坐标下的径向分量以提高重建图像的质量,实验结果表明,此算法在压缩比和重建质量方面都取得较好的效果。 相似文献
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针对一款基于DMD的光谱维编码Offner光谱成像仪对凸面闪耀光栅的性能要求,提出了一种凸面闪耀光栅的宏观-微观一体化优化设计方法,利用三维偏振光追迹算法有机融合了宏观层面的Offner光学系统设计与微观层面的凸面闪耀光栅槽型设计。介绍了编码孔径Offner光谱成像系统的组成和工作原理,并结合系统的使用要求设计了一款平均衍射效率为85.47%的中波红外凸面闪耀光栅。在此基础上,采用超精密单点金刚石车床成功制备了曲率半径为120 mm、周期为99.945 μm、闪耀角为1.1783°、槽深为1.834 μm的凸面闪耀光栅。测试结果表明,在3~5 μm光谱范围内,最大衍射效率为93.46%,平均衍射效率为84.29%,与理论设计值较为吻合,验证了凸面闪耀光栅设计方法的有效性。 相似文献
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在双色散结构编码孔径光谱成像系统(DD-CASSI)的基础上,提出了利用多帧采样图方法(Multi Frame-DD-CASSI),以提高信息采样率,并提出新的数学模型,实现了对三维数据立方体的光谱维压缩编码,充分利用了光谱维数据的相关性,利用32帧采样图恢复数据,达到了0.99的光谱曲线相似度和40 db的图像峰值信噪比. 相似文献
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针对近期提出的基于压缩感知(CS,compressed sensing)理论的压缩编码成像方法在重建后引入较多类似于噪声的伪影(artitacts)问题,为了使压缩编码成像方法获得更好成像质量的图像,本文提出一种改进的压缩编码成像方法。本文方法将多值模板(MVM)代替二值模板来增强编码质量,并利用自适应全变分(TV,total variation)去噪方法去除重建后的高分辨率图像的伪影。实验结果表明,这种方法很好地改进了压缩编码孔径(CCA)的成像质量,并且大幅提高了图像的信噪比(SNR)。 相似文献
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Processing of synthetic aperture radar (SAR) data coded with one bit is considered. The one bit coding operation amounts to the retention of only the information about the sign of the signals involved (signum coding or SC). The paper reviews the theory of signum coding and evaluates its performance by computing some quality measures for real images. Numerical results, which are in accord with theory, show that only a slight degradation in the quality of the images obtained is introduced by the SC operation if the signal is sampled at a rate consistent with the original bandwidth. If the sampling frequency is increased, the quality obtained can be further improved. Since the data involved in the processing are binary sequences, the processing can be carried out in real time, on-board the moving platform carrying the SAR antenna, and by using dedicated hardware consisting of simple, small, low-cost devices, which can be on motherboards of small dimensions and absorb very little power 相似文献
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为满足对飞行目标的多维光谱探测和可见光成像需求,设计了一款基于卡塞格林望远镜结构的共孔径光学系统。系统前端由同轴两反系统组成,主镜为抛物面,次镜为双曲面,后端通过平板分光的方式由各子系统接收。在可见光成像端,利用两片柱面镜成功解决了分光平板引起的像散问题,并通过添加反向倾斜的补偿平板,校正了分光平板引起的光轴偏移问题,可实现对距离为0.5~1.5 km、直径为0.5 m的飞行目标进行可见光成像和多波段光谱接收(200~400 nm、400~760 nm及760~2 500 nm)。成像模块各视场在奈奎斯特频率35 lp/mm处均实现了MTF>0.5,趋近于衍射受限曲线,各光谱接收模块也均满足光纤耦合要求。通过无热化设计,该共孔径系统可实现在?20~50 ℃温度范围内正常工作。公差分析结果表明,该系统能够满足实际加工和装调要求。 相似文献
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Spectral images (SI) can be represented as 3D-arrays of spatial information across multiple wavelengths. Compressive Spectral Imaging (CSI) reduces sensing costs by sensing compressed versions of the scene, recovering a suitable version of the original SI solving a sparsity-inducing inverse problem. On the other hand, Convolutional Sparse Coding (CSC) has been successfully proved for representing gray-scale images, however it misses any correlation between images. This work considers the spatial-spectral correlation within SIs introducing an extension of the CSC signal model describing the SI as the sum of convolutions of 3D sparse coefficient maps with their respective 3D dictionary filters. Furthermore, we use the proposed CSC framework for recovering SIs from CSI measurements. The simulations results, using two different CSI acquisition architectures, show that the proposed CSC framework yields better representations of the SIs than those obtained under the traditional sparse signal representation approach, improving the quality of the recovered SIs. 相似文献
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Synthetic aperture imaging lidar is an active new imaging system, which can offer a finer azimuth resolution than the SAR system. An indoor system of synthetic aperture imaging lidar is given, which is a demonstration about synthetic aperture to image rotating objects. Firstly, the basic principle is introduced. Then, the basic method and key techniques are analyzed. After that an improved system is given with the transmitting and the receiving lens apart from each other which can eliminate the interference... 相似文献
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A full frequency diversity COFDM (FD-COFDM) scheme based on sub-channel multiplexing is proposed to improve the performance of COFDM without sacrificing spectral efficiency. Since the channel suffers the frequency selective fading, the received signal contains strong inter-symbol interference (ISI). To obtain the diversity- and code-gains, an iterative receiving algorithm is presented. By jointly using diversity combining, interference cancelation and soft decoding, the proposed iterative receiving algorithm properly decodes the information bits in the strong ISI environment. Consequently, all the subcarriers of FD-COFDM participate in diversity so that the system can achieve full frequency diversity in most practical channels. The new receiving algorithm is relatively simple compared to the maximum likelihood estimation algorithm, and is therefore a better alternative to balance the algorithm complexity and system performance. 相似文献
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提出了一种基于压缩传感理论的光子计数成像系统。该系统以单光子计数器作为探测元件,以期在面元探测技术不甚成熟的现状下用点探测器进行极弱光探测。通过计算机模拟计算,验证了压缩传感理论结合单光子计数器应用于极弱光成像的可行性,讨论了单光子计数器的暗计数率、量子效率和测量噪声对成像质量的影响。介绍了压缩传感理论,为了获得更好的图像质量和更快的计算速度,提出了SpaRSA-DWT稀疏重建算法,并与传统的IWT算法进行对比。给出了两种算法下,迭代次数、测量数、噪声功率分别与获得图像信噪比的关系曲线,证明了SpaRSA-DWT算法的优越性。 相似文献
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波前编码景深延拓研究进展 总被引:1,自引:0,他引:1
波前编码成像技术(WFC)是一种用于景深延拓非常有效的光数混合图像处理技术,本文在简单介绍WFC技术基本原理的基础上,分层次系统介绍了WFC技术的最新设计理论和现实指导意义,举例说明了WFC技术的实际应用价值,最后对波前编码成像技术现状和未来做了简单探讨。 相似文献