Dependence of the results of classification of multispectral images of forest vegetation on wavelet-transform parameters

The problem of classification of space multispectral images of forest vegetation is considered. Features based on the wavelet transform and a classification method involving consideration of the importance of each feature are investigated. Dependence of the classification results on the wavelet function, the level of the transform, and the parameter of the classification method — the number of segments of the range of features — is given. Results of classification of multispectral images of six classes of forest vegetation in images obtained by a Rapid Eye shooting system are presented.     

多光谱 CCD 相机几何标定技术研究

多光谱CCD相机的技术特点是利用不同遥感谱段获得同一目标图像,通过不同谱段图像的组合,获取地物目标的物理特性。为了使多光谱CCD相机同时还具备测绘功能,能对获取的地物目标进行精确定位,发射前需要在实验室对多光谱CCD相机的几何参数进行精确标定。多光谱CCD相机几何标定是相机研制过程中的关键环节,是确定相机在惯性坐标系中姿态的必不可少的关键技术。本文着重介绍了多光谱CCD相机几何标定设备、标定方法和标定精度。多次标定结果表明：主距的标定精度优于10μm （1σ）,主点的标定精度优于2.1μm （1σ）,畸变的标定精度优于1.5μm （1σ）,满足多光谱CCD相机几何标定精度的要求。     

Enhanced EDX images by fusion of multimodal SEM images using pansharpening techniques

The goal of this paper is to explore the potential interest of image fusion in the context of multimodal scanning electron microscope (SEM) imaging. In particular, we aim at merging the backscattered electron images that usually have a high spatial resolution but do not provide enough discriminative information to physically classify the nature of the sample, with energy‐dispersive X‐ray spectroscopy (EDX) images that have discriminative information but a lower spatial resolution. The produced images are named enhanced EDX. To achieve this goal, we have compared the results obtained with classical pansharpening techniques for image fusion with an original approach tailored for multimodal SEM fusion of information. Quantitative assessment is obtained by means of two SEM images and a simulated dataset produced by a software based on PENELOPE.     

Three-Dimensional Fusion of Multispectral Secondary Ion Mass Spectrometry Images

Imaging secondary ion mass spectrometry (SIMS) is a powerful surface analysis tool capable of producing two-(2D) and three-dimensional (3D) spatially resolved images of element distributions. Both the 2D and the 3D imaging mode produce multispectral images, i.e., each image stack visualises the lateral distribution of one element, which divides the sample information into a number of individual images. Visual perception of the sample information is aggravated by this—for example, the exact spatial location of different elements relative to each other, formation of occlusions or segregations, etc.—is often hard to recognize when looking at n separate images, especially regarding 3D depth profiles. Image fusion is a process whereby images obtained from various sensors, or at different moments of time, or under different conditions, are combined together to provide a more complete picture of the object under investigation. The use of colour introduces a new dimension of information and can be used to simplify image analysis and object identification. This work introduces a complete methodology that enables the calculation and rendering of 3D colour images of multispectral SIMS depth-profiles based on the use of adaptive color and transparency maps. Examples of 3D SIMS images are given but the technique may be expanded to fusion and visualization of any other multispectral 3D image stack.     

Planetamonitoring Software Complex in Applied Remote Sensing Problems

This paper describes a PlanetaMonitoring software complex, developed jointly by the Scientific Research Center “Planeta” and the Institute of Computational Mathematics and Mathematical Geophysics of the Siberian Branch of the Russian Academy of Sciences, which implements the software for pre-processing and thematic processing of multispectral satellite images of optical, infrared, and microwave ranges. This work also touches upon the pre-processing of satellite data, particularly brightness and geometric transformations, geocoding, and compilation of survey installation. Thematic processing of multispectral satellite images by software for object recognition (without and with training), detection and mapping of lineaments and circular structures, as well as determination of spatial displacements of natural objects (ice fields, water masses, and cloud formations in the atmosphere) over time-different satellite images is described. This software is used to solve a number of applied problems of Earth remote sensing.     

基于多光谱图像选取马铃薯叶片的最佳彩色波段组合

为了快速目测识别马铃薯叶片,利用Spectrocam多光谱相机获取健康C-88马铃薯叶片的可见光及近红外通道的多光谱图像。采用波段指数法提取叶片的特征波段,通过真彩色原理及标准假彩色对所提取的特征波段进行彩色合成,在此基础上得到最佳彩色波段组合。实验结果表明,用波段指数法提取多光谱图像的特征波段进行彩色合成,能快速获取马铃薯叶片的最佳波段,并得到680,558,475nm和800,680,558nm为最佳彩色波段组合,为遥感图像的目视解译和更多有效信息的提取提供了可靠依据。     

Versatile multispectral microscope based on light emitting diodes

We describe the development of a novel multispectral microscope, based on light-emitting diodes, capable of acquiring megapixel images in thirteen spectral bands from the ultraviolet to the near infrared. The system captures images and spectra in transmittance, reflectance, and scattering modes. We present as examples of applications ground truth measurements for remote sensing and parasitology diagnostics. The system is a general purpose scientific instrument that could be used to develop dedicated simplified instruments with optimal bands and mode selection.     

Search for man-made objects with the use of their structural features

The most essential constraints of conventional technologies of processing multispectral data of remote sensing of the Earth in solving the problem of searching for man-made objects are analyzed. Several methods using structural features of images of man-made objects are modeled and studied. The efficiency of approaches based on classification of fragments with the use of the Harris detectors is demonstrated.     

多源遥感数据的道路提取技术研究现状及展望

遥感图像道路信息提取既是土地利用检测、地理信息系统更新等传统行业应用的必要步骤,又是数字城市、智能交通等新基建领域中关键技术之一.回顾道路提取方法的发展历程,按照使用数据源的不同,现有的遥感图像道路提取技术主要分为高分辨率成像、多光谱/高光谱成像、激光/点云成像和SAR成像四大类.本文首先介绍了四种遥感技术在道路信息提...     

基于 Karhunen-leove 变换的多光谱数据压缩统计特性分析

提出了基于Karhunen-leove变换(KLT)的多光谱图像数据压缩方法,并对多光谱图像数据KLT统计特征进行了分析。在对KLT进行了理论推导后,如何将该方法应用于实际多光谱数据压缩系统进行了分析讨论。研究提出了一种最大限度地减少额外码流开销的方法。实验结果表明:该方法对16光谱段的三维数据可获得3.2～5.3的压缩比,且几乎没有失真,明显优于用DCT去除谱相关性的方法。     

Simultaneous Fusion and Denoising of Panchromatic and Multispectral Satellite Images

To identify objects in satellite images, multispectral (MS) images with high spectral resolution and low spatial resolution, and panchromatic (Pan) images with high spatial resolution and low spectral resolution need to be fused. Several fusion methods such as the intensity–hue–saturation (IHS), the discrete wavelet transform, the discrete wavelet frame transform (DWFT), and the principal component analysis have been proposed in recent years to obtain images with both high spectral and spatial resolutions. In this paper, a hybrid fusion method for satellite images comprising both the IHS transform and the DWFT is proposed. This method tries to achieve the highest possible spectral and spatial resolutions with as small distortion in the fused image as possible. A comparison study between the proposed hybrid method and the traditional methods is presented in this paper. Different MS and Pan images from Landsat-5, Spot, Landsat-7, and IKONOS satellites are used in this comparison. The effect of noise on the proposed hybrid fusion method as well as the traditional fusion methods is studied. Experimental results show the superiority of the proposed hybrid method to the traditional methods. The results show also that a wavelet denoising step is required when fusion is performed at low signal-to-noise ratios.     

Multimodal microscopy by digital image processing

A matching algorithm is proposed for aligning microscope images obtained using different modalities, making use of cross-correlations of outputs from Prewitt's edge filter. Brightfield, phase contrast and differential interference contrast microscope images of algal and bacterial cells from an experimental, high-rate algal pond are used for illustration. The information content of multimodal images is explored using principal components analysis and colour displays, and an image which represents optical thickness is constructed digitally.     

基于多光谱成像技术的水稻特征光谱提取

为了获取水稻光谱的有效特征信息,选取健康的TN1#水稻幼苗为研究对象,利用由液晶可调谐滤波器、单色CMOS相机与计算机控制软件组成的多光谱图像采集系统,获取健康水稻幼苗的20个可见光通道的多光谱图像。在此基础上,采用多光谱图像的平均灰度值,通过波段选择的指数方法计算出各通道的波段指数并加以排序,选出波段指数较大的10个通道,目的是探讨能有效反映出水稻特征光谱信息的特征波段。实验结果表明,用波段选择的指数方法提取多光谱图像的特征波段,能快速获取水稻的叶片信息。通道475nm、500nm、530nm、545nm、550nm、520nm、560nm、630nm、660nm、720nm能更好地反映出水稻特征光谱信息,可作为水稻的有效特征信息通道。     

不同角度下马铃薯多光谱图像的植叶面积提取

为了更好地研究马铃薯光谱特性,对马铃薯植株的植叶面积进行了探究。采用Spectrocam多光谱相机对光以不同照射角度照射下的植叶面积进行数据采集,并运用软件对数据进行二值化处理和亮度处理。实验结果表明,在中心波长为750nm和800nm的通道下,计算出的马铃薯植叶面积差异不大,但是将两者的二值图与原图进行细节对比,中心波长为800nm的通道的二值图与原图较为吻合,所以中心波长为800nm的通道是计算马铃薯植叶面积的最优通道。     

多光谱视觉检测系统及其在稻飞虱发生早期检测中的应用

为了研究作物病虫害发生后植株冠层多光谱图像特征值的变化规律,设计了一套室内多光谱视觉检测系统试验平台。文章介绍了该试验平台在稻飞虱发生早期水稻冠层多光谱图像特性研究中的应用。在实验室条件下对盆栽稻株进行接虫,然后分12个时段(接虫后14h、16h、20h、22h、24h、38h、44h、48h、62h、69h、73h)对受稻飞虱侵害后的稻株冠层进行多光谱图像采集,共采集到NIR、R、G、B四个通道及其组合通道(CIR、RGB)的稻株冠层图像561张,然后在Matlab中进行图像处理和数据分析,结果表明:稻飞虱迁入后,NIR通道的冠层叶片灰度值算术平均值在时间维度上光谱图像特征值变化非常显著,其次是G、R通道。因此,在稻飞虱迁入后,应着重观察NIR、G、R通道冠层叶片灰度值算术平均值在时间维度上的变化规律,从中挖掘用于稻飞虱入侵检测和危害程度分级的相关模型。     

Compression of fluorescence microscopy images based on the signal-to-noise estimation

Modern microscopic techniques like high-content screening (HCS), high-throughput screening, 4D imaging, and multispectral imaging may involve collection of thousands of images per experiment. Efficient image-compression techniques are indispensable to manage these vast amounts of data. This goal is frequently achieved using lossy compression algorithms such as JPEG and JPEG2000. However, these algorithms are optimized to preserve visual quality but not necessarily the integrity of the scientific data, which are often analyzed in an automated manner. Here, we propose three observer-independent compression algorithms, designed to preserve information contained in the images. These algorithms were constructed using signal-to-noise ratio (SNR) computed from a single image as a quality measure to establish which image components may be discarded. The compression efficiency was measured as a function of image brightness and SNR. The alterations introduced by compression in biological images were estimated using brightness histograms (earth's mover distance (EMD) algorithm) and textures (Haralick parameters). Furthermore, a microscope test pattern was used to assess the effect of compression on the effective resolution of microscope images.     

基于Red-Black小波变换的多光谱图像融合方法

针对张量积小波在多光谱图像融合中的不足,提出了一种基于Red-Black小波变换的多光谱图像和高空间分辨率全色图像融合方法.首先对多光谱图像进行IHS变换,将得到的亮度分量和高空间分辨率全色图像进行直方图匹配,并分别作多尺度Red-Black小波分解,然后对低频部分采用加权平均、高频部分采用替代的融合算法对分解子图像进行融合,最后对融合后的各级子图像进行Red-Black重构和IHS逆变换得到融合结果图像,采用客观性能指标对融合结果图像进行了评价.实验结果表明,该方法有较好的融合效果,其保持光谱质量和空间分辨率信息的能力比基于IHS变换融合方法、基于DWT的融合方法和基于IHS-DWT的融合方法都强.     

利用高斯混合模型的多光谱图像模糊聚类分割

针对传统分割算法难以实现高分辨率多光谱图像分割的问题,本文提出一种利用高斯混合模型的多光谱图像模糊聚类分割算法。该算法采用高斯混合模型定义像素对类属的非相似性测度,由于该算法具有高精度拟合数据统计分布能力,故可以有效剔除噪声对分割结果的影响。同时,引入隐马尔科夫随机场(Hidden Markov Random Field,HMRF)定义邻域作用的先验概率,并将其作为各高斯分量权值以及KL(Kullback-Leibler)信息中控制聚类尺度的参数,从而增强了算法对复杂场景遥感图像的鲁棒性,进一步提高了算法的分割精度。对模拟图像和高分辨多光谱图像分割结果进行了定性定量分析。实验结果表明:模拟图像的总精度达96.8%以上。这验证了本文算法在分割高分辨率多光谱图像时具有保留细节信息的能力,而且也证实了算法的有效性和可行性。该算法能够实现高分辨率多光谱图像的精确分割。     

基于紫外光诱导荧光的渗透性纸张上微量物证检测技术研究

为解决刑事案件中附着于渗透性纸张上的无色微量物证探测难的问题,分析常用纸张的紫外荧光特性,为滤除纸张上的强背景荧光提供依据,研制基于紫外光诱导荧光的渗透性纸张上微量物证检测装置。检测装置中,为有效激发各种微量物质荧光,采用光子能量高的深紫外激光作为激发光源;为获得更准确的痕迹信息,装置接收多光谱荧光并进行结果比对;同时,提出以背景灰度标准差来衡量纸张荧光的均匀性,以图像痕迹对比度评价痕迹的检测效果。使用本装置对常用纸张上的指印、明矾等5种无色痕迹开展实验验证,结果表明,所提方法能清晰显现纸张上的潜指印,且获得的指印条纹对比度与纸张背景灰度标准差成反比;同时,学生作业纸上的10%明矾溶液痕迹信息、复印纸上的2.5%谷氨酸钠溶液痕迹信息、便利贴上的2.5%磺酸钠溶液痕迹信息、便利贴上的0.004%硫酸铜溶液痕迹信息均能清晰显现。所提方法具有检测灵敏度高、非接触性、非破坏性、多光谱等优点,能快速获得高荧光纸张上多种微弱痕迹的清晰图像,为刑事侦查提供有力的帮助。