Overlapped rectangle image representation and its application to exact legendre moments computation     

Wei Huang  Chuanbo Chen  Mudar Sarem  Yunping Zheng 《地球空间信息科学学报》2013,16(4):294-301

Linear quadtree is a popular image representation method due to its convenient imaging procedure. However, the excessive emphasis on the symmetry of segmentation, i.e. dividing repeatedly a square into four equal sub-squares, makes linear quadtree not an optimal representation. In this paper, a no-loss image representation, referred to as Overlapped Rectangle Image Representation (ORIR), is presented to support fast image operations such as Legendre moments computation. The ORIR doesn’t importune the symmetry of segmentation, and it is capable of representing, by using an identical rectangle, the information of the pixels which are not even adjacent to each other in the sense of 4-neighbor and 8-neighbor. Hence, compared with the linear quadtree, the ORIR significantly reduces the number of rectangles required to represent an image. Based on the ORIR, an algorithm for exact Legendre moments computation is presented. The theoretical analysis and the experimental results show that the ORIR-based algorithm for exact Legendre moments computation is faster than the conventional exact algorithms.  相似文献   

Designing thought,technical line and some theoretical issues on geospatial digital framework of China     

Hu Peng  Hu Yuju  Yang Chuanyong  Wu Yanlan  Hu Hai 《地球空间信息科学学报》2013,16(3):33-40

Based on the developing tendency of present China's basic GIS, this paper discusses the designing idea for scales of 1∶10 000, 1∶50 000, 1∶250 000 and 1∶1 000 000 pyramidlike multi-layer and multi-resolution of the basic GIS. A technical line for the construction of basic GIS of the whole country and various provinces for sustainable development is put forward. And some important theoretical GIS issues touched by the technical process are discussed.  相似文献   

Shadow detection and compensation for color aerial images     

Wang Shugen  Guo Zejin  Li Deren 《地球空间信息科学学报》2013,16(3):20-24

A method for shadow detection and compensation for color aerial images is presented. It is considered that the intensity value of each image pixel is the product of illumination function and ground object reflection, and the shadowed regions on the image are mainly caused by the short of illumination, so the information compensation for the shadowed regions should concentrate on the illumination adjustment of concerned area on the basis of the analysis of whole image. The shadow detection and compensation procedure proposed by this paper consists of four steps.  相似文献   

Data fusion technique for multibeam echosoundings     

Huang Motao  Zhai Guojun  Ouyang Yongzhong  Liu Yanchun 《地球空间信息科学学报》2013,16(3):11-18

On the basis of an analysis of the error sources in multibeam echosounding system, a data processing method for compensating systematic errors in multibeam survey is proposed. In order to improve the accuracy of overall swath, a data fusion technique using single beam survey data as control information for single beam and multibeam echosounding is then presented. Some questions involved in solving the adjustment problem, such as its feasibility and the numerical stability, are discussed in detail, and a two-step adjustment method is suggested. Finally, a practical survey data set is used as a case study to prove the efficiency and reliability of the proposed methods.  相似文献   

System structure and calibration models of intelligent photogrammetron     

Pan Heping  Zhang Chunsen 《地球空间信息科学学报》2013,16(2):48-54

This paper describes the structure, geometric model and geometric calibration of Photogrammetron I—the first type of photogrammetron which is designed to be a coherent stereo photogrammetric system in which two cameras are mounted on a physical base but driven by an intelligent agent architecture. The system calibration is divided into two parts: the in-lab calibration determines the fixed parameters in advance of system operation, and the in-situ calibration keeps tracking the free parameters in real-time during the system operation. In a video surveillance set-up, prepared control points are tracked in stereo image sequences, so that the free parameters of the system can be continuously updated through iterative bundle adjustment and Kalman filtering.  相似文献   

The hypermedia data model based on the infinity image     

Wan Xiaoxia 《地球空间信息科学学报》2013,16(4):48-53

This paper presents the hypermedia data model based on the infinity RS image information system we have developed. The hypermedia data model consists of different semantic units called nodes, and the associations between nodes are called links. This paper proposes three kinds of nodes (interior node, physical node and complex node) and two kinds of links (plane network structure link, hyper-cube network structure links). The hypermedia information system, based on the model and the basic data layer (the infiniy RS image), represents a digital globe. An approach to the “Getting Lost in the Hyper-space” problem is presented. The approach using the hypermedia data model is an efficient way of handling a large number of RS images in various geographical information systems.  相似文献   

Quantifying urban land cover change between 2001 and 2006 in the Gulf of Mexico region     

George Xian  Collin Homer  Brett Bunde  Patrick Danielson  Jon Dewitz  Joyce Fry 《国际地球制图》2013,28(6):479-497

We estimated urbanization rates (2001–2006) in the Gulf of Mexico region using the National Land Cover Database (NLCD) 2001 and 2006 impervious surface products. An improved method was used to update the NLCD impervious surface product in 2006 and associated land cover transition between 2001 and 2006. Our estimation reveals that impervious surface increased 416 km² with a growth rate of 5.8% between 2001 and 2006. Approximately 1110.1 km² of non-urban lands were converted into urban land, resulting in a 3.2% increase in the region. Hay/pasture, woody wetland, and evergreen forest represented the three most common land cover classes that transitioned to urban. Among these land cover transitions, more than 50% of the urbanization occurred within 50 km of the coast. Our analysis shows that the close-to-coast land cover transition trend, especially within 10 km off the coast, potentially imposes substantial long-term impacts on regional landscape and ecological conditions.  相似文献   

Assessing image processing techniques for geological mapping: a case study in Eljufra,Libya     

N. M. Saadi  K. Watanabe 《国际地球制图》2013,28(3):241-253

Various image processing techniques were experimented with in this study to evaluate their efficiency for geological mapping in the Eljufra area of northwest Libya. Remote sensing data including multi-spectral optical Landsat Enhanced Thematic Mapper (ETM+), Synthetic Aperture Radar (ERS-2 SAR) and Digital Elevation Models (DEMs) extracted from the Shuttle Radar Topography Mission (SRTM) data were used to trace different lithological units as well as extracting geological lineaments in the study area. The study area is located in an arid environment mostly devoid of any vegetation. Most lithological and structural units are distinguishable based on their topographic form and spectral properties. Fusion of ETM+ and ERS-2 images was experimented with to further identify lithological units. Shaded relief techniques were implemented to enhance terrain perspective views and to extract geological lineaments. The results discriminated different rock units and modified formation boundaries and revealed new geological lineaments. Nine rock units were identified and plotted in the new geological map defined by the new boundaries. The dominant lineaments tend to run in the NNW-SSE and NNE-SSW directions. Analysis and interpretation of the lineaments provided information about the tectonic evolution of the study area.  相似文献   

Mapping spiny aster infestations with QuickBird imagery     

J. H. Everitt  C. Yang  D. L. Drawe 《国际地球制图》2013,28(4):273-283

QuickBird satellite imagery acquired in June 2003 and September 2004 was evaluated for detecting the noxious weed spiny aster [Leucosyris spinosa (Benth.) Greene] on a south Texas, USA rangeland area. A subset of each of the satellite images representing a diversity of cover types was extracted and used as a study site. The satellite imagery had a spatial resolution of 2.8 m and contained 11-bit data. Unsupervised and supervised classification techniques were used to classify false colour composite (green, red, and near-infrared bands) images of the study site. Imagery acquired in June was superior to that obtained in September for distinguishing spiny aster infestations. This was attributed to differences in spiny aster phenology between the two dates. An unsupervised classification of the June image showed that spiny aster had producer's and user's accuracies of 90% and 93.1%, respectively, whereas a supervised classification of the June image had producer's and user's accuracies of 90% and 81.8%, respectively. These results indicate that high resolution satellite imagery coupled with image analysis techniques can be used successfully for detecting spiny aster infestations on rangelands.  相似文献   

Validating the use of object-based image analysis to map commonly recognized landform features in the United States     

Samantha T. Arundel  Gaurav Sinha 《制图学和地理信息科学》2013,40(5):441-455

ABSTRACT

The U.S. Geological Survey (USGS) National Geospatial Program (NGP) seeks to i) create semantically accessible terrain features from the pixel-based 3D Elevation Program (3DEP) data, and ii) enhance the usability of the USGS Geographic Names Information System (GNIS) by associating boundaries with GNIS features whose spatial representation is currently limited to 2D point locations. Geographic object-based image analysis (GEOBIA) was determined to be a promising method to approach both goals. An existing GEOBIA workflow was modified and the resulting segmented objects and terrain categories tested for a strategically chosen physiographic province in the mid-western US, the Ozark Plateaus. The chi-squared test of independence confirmed that there is significant overall spatial association between terrain categories of the GEOBIA and GNIS feature classes. Contingency table analysis also suggests strong category-specific associations between select GNIS and GEOBIA classes. However, 3D visual analysis revealed that GEOBIA objects resembled segmented regions more than they did individual landform objects, with their boundaries often failing to correspond to match what people would likely perceive as landforms. Still, objects derived through GEOBIA can provide initial baseline landscape divisions that can improve the efficiency of more specialized feature extraction methods.  相似文献