共查询到19条相似文献，搜索用时 125 毫秒
1.
2.
随着我国自主研发卫星组网的不断完善,利用遥感变化检测技术进行海岸带变化检测成为海岸带监测的重要手段。针对沿海地区的变化信息提取,文章首先利用多特征构建差异影像,在此基础上采用两种集成学习方式:随机森林（Random Forest）和极端梯度提升（XGBoost）,进行试验区的变化检测,并与传统的机器学习SVM、经典的变化检测方法CVA和IR-MAD进行对比,结果表明集成学习进行变化信息提取效率远超其余方式,且XGBoost在变化信息提取精度方面具有一定优势。研究成果对海岸带及海域使用开展自动化变化监测和海岸带监督管理具有重要意义。 相似文献
3.
4.
通过研究、分析现有基于遥感影像的舰船检测算法,提出了基于Itti视觉显著度模型改进的高分辨率遥感影像海面舰船检测方法,该方法利用海面舰船相对于海面背景信息视觉关注高的特点,参考视觉显著度模型计算原理,对高分辨率遥感影像中的颜色、亮度、方向、纹理等特征进行有效提取,然后利用归一化方法将不同特征融合,形成有利于舰船目标提取得视觉显著度图,最后对生成的视觉显著度图进行阈值分割和精细化处理获得最终的舰船检测结果。与传统舰船检测算法相比,本文算法能够有效检测复杂海面背景下的舰船目标,减少了单一特征变化对检测精度的影响,提高了检测准确率,具有较好的抗噪性和较强的鲁棒性。 相似文献
5.
基于高分辨率遥感影像的西沙赵述岛地表覆盖提取与演变分析 总被引：1，自引：0，他引：1
《热带海洋学报》2016,(2)
海岛礁地表覆盖演变分析对海岛礁开发利用、海洋资源保护、海洋经济开发等具有重要作用。基于高分辨率遥感影像,利用遥感与地理信息系统(geographic information system,GIS)技术,对西沙宣德群岛之赵述岛2008—2014年间的地表覆盖情况进行分类提取并变化检测,形成赵述岛多期地表覆盖现状图。构建了海岛礁地表覆盖分类体系,在此分类基础上采用地表覆盖转移矩阵,结合净变化量、交换变化量、总变化量等变化参数对研究期内赵述岛地表覆盖变化进行了分析。 相似文献
6.
7.
8.
9.
10.
11.
Foresti G.L. Murino V. Regazzoni C.S. Trucco A. 《Oceanic Engineering, IEEE Journal of》1997,22(1):57-65
This paper describes a voting-based approach for the fast automatic recognition of man-made objects and related attitude estimation in underwater acoustic images generated by forward-looking sonars or acoustic cameras. In general, the continuous analysis of sequences of images is a very heavy task for human operators and this is due to the poor quality of acoustic images. Hence, algorithms able to recognize an object on the basis of a priori knowledge of the model and to estimate its attitude with reference to a global coordinate system are very useful to facilitate underwater operations like object manipulation or vehicle navigation. The proposed method is capable of recognizing objects and estimating their two-dimensional attitude by using information coming from boundary segments and their angular relations. It is based on a simple voting approach directly applied to the edge discontinuities of underwater acoustic images, whose quality is usually affected by some undesired effects such as object blurring, speckle noise, and geometrical distortions degrading the edge detection. The voting approach is robust, with respect to these effects, so that good results are obtained even with images of very poor quality. The sequences of simulated and real acoustic images are presented in order to test the validity of the proposed method in terms of average estimation error and computational load 相似文献
12.
ABSTRACTIn studies of changes in island geographic information, a key topic is island land cover change detection using multitemporal remote sensing images; such information can provide good reference for island exploitation, marine resource conservation, marine economic development, and national defense building. This study proposes a fast and easy-to-implement algorithm of object-oriented change detection based on iteratively reweighted multivariate statistical analysis with high-resolution remote sensing images and vector data, improving effects of normal multivariate alternative detection by combining object-oriented technology with probability density function of chi-square distribution. This method builds vectors in feature space with spectral, texture, and spatial structure information of objects segmented based on boundaries and categories of features in vector data. By feature optimization and iterative extension to multivariate statistical analysis for change detection, change regions can be extracted. Experiments on Zhaoshu Island area show that the proposed method is highly effective and accurate in detection of change regions. 相似文献
13.
14.
《Oceanic Engineering, IEEE Journal of》1997,22(1):40-46
Sector-scanning sonar systems image the sea bottom to detect objects that can be distinguished from the background structure of the sea bottom. In current systems, images are displayed and discarded as new image data become available, In this paper, a method for improving sonar detection by utilizing all images in a sequence is investigated. The proposed method requires that sonar data are acquired with a sector-scanning sonar in a side-looking configuration. It is demonstrated that these data can be used to detect observation-point-dependent changes in sea-bottom backscattering characteristics. These changes provide additional cues for discrimination that can improve the detection of objects on the sea bottom. Results of applying the method to experimental data are presented 相似文献
15.
This paper explores the geometric performance of integration of aerial and QuickBird images. Different integration scenarios with different bias compensation schemes in the image space were studied, and the results showed that the introduction of the aerial images can improve the geopositioning accuracy of the QuickBird images to close to the aerial pixel level. In addition, methods of correcting biases in the object space were tested, and the results revealed the disadvantage of the bias compensation in the object space. An experiment was conducted for mapping ground objects such as inland rivers, buildings, and roads using the proposed integration method. 相似文献
16.
冰面水体是冰盖物质平衡的重要组成部分,在全球气候及环境变化研究中发挥着重要的作用。本文以格陵兰岛北部为研究区,选取该研究区消融期内不同时相的WorldView-2影像,对区域内典型地物统计分析其光谱特性,构建了针对冰面水体的归一化水体增强指数NEWI（Normalized Enhanced Water Index。依据影像上地物分布规律和直方图图形特征,对冰雪混合物和冰面水体边缘地带灰度值相似的模糊区域定位,增强区域间地物对比度,提取出冰面水体的精细范围。实验结果表明,本研究所提出的指数有效凸显了冰面水体与非水体的反射率差异,与常用的水体指数NDWI等相比,在冰川环境下,提高区分度方面优势明显。通过精度评价可知,本文方法所提取出的冰面水体精细化程度高,提取结果完整,错误率低。本研究对冰面水体信息增强及精细化提取具有重要参考价值。 相似文献
17.
Daniel S. Le Leannec F. Roux C. Soliman B. Maillard E.P. 《Oceanic Engineering, IEEE Journal of》1998,23(3):245-259
This paper presents a method for the matching of underwater images acquired with acoustic sensors. As a final objective, the system aims at matching data from two-dimensional scenes. The proposed approach carries out a hypothetical reasoning based on objects, represented by shadows and echoes in the sonar images, and their available features. The problem of determining measures which are invariant to changes in sonar settings and noise characteristics is addressed by mapping robust features for sonar images to a qualitative representation. To cope with the viewpoint charging appearance, the method is based on the conservation of objects' relative position from one image to another. We attempt to match geometrical structures formed by the association of three objects. The hypothetical reasoning is conducted in a decision tree framework. A tree node is generated by two objects' association, each one belonging to a respective image. Hypotheses propagation consists of creating new nodes from neighboring associations. The matching solution is determined by the selection of the decision tree's longest branch. Thus, the association mechanism is a depth-first procedure. The proposed method has been applied to real high-resolution side-scan sonar images. The matching process has shown successful and promising results which have been further improved. In particular, the parceled shadows (during the segmentation procedure) problem has been tackled 相似文献
18.
通过迭代CFAR算法，本文发展了一种针对分块SAR图像的冰山检测方法。考虑到滑动窗口运算负担大、计算效率低，首先对SAR图像进行分块，以提取分块内的亮目标冰山。利用高斯模型表征后向散射系数的统计分布，冰山检测阈值可简单地表达为均值和方差的线性组合，将分块内像素逐个比对阈值以检测冰山。考虑到同一场景中尺寸变化大的冰山影响检测精度，以识别的冰山像素做种子执行区域生长，从而提取大尺寸的冰山。针对单个分块迭代上述处理，以降低高斯模型表征分块统计分布的误差，提高冰山检测精度。利用2013年11月22日和29日获取自极地海域的两景RADARSAT-2图像开展验证试验。结果表明，数量多、尺寸变化大并嵌入在海冰等极地常见情形下的冰山，能被文中方法有效识别，选取区域内正确率高达85%以上，且具有良好的运行效率。 相似文献
19.
The fast update rate and good performance of new generation electronic sector scanning sonars is now allowing practicable use of temporal information for signal processing tasks such as object classification and motion estimation. Problems remain, however, as objects change appearance, merge, maneuver, move in and out of the field of view, and split due to poor segmentation. This paper presents an approach to the segmentation, two-dimensional motion estimation, and subsequent tracking of multiple objects in sequences of sector scan sonar images. Applications such as ROV obstacle avoidance, visual servoing, and underwater surveillance are relevant. Initially, static and moving objects are distinguished in the sonar image sequence using frequency-domain filtering. Optical flow calculations are then performed on moving objects with significant size to obtain magnitude and direction motion estimates. Matches of these motion estimates, and the future positions they predict, are then used as a basis for identifying corresponding objects in adjacent scans. To enhance robustness, a tracking tree is constructed storing multiple possible correspondences and cumulative confidence values obtained from successive compatibility measures. Deferred decision making is then employed to enable best estimates of object tracks to be updated as subsequent scans produce new information. The method is shown to work well, with good tracking performance when objects merge, split, and change shape. The optical flow is demonstrated to give position prediction errors of between 10 and 50 cm (1%-5% of scan range), with no violation of smoothness assumptions using sample rates between 4 and 1 frames/s 相似文献