bluuebunny/crossref_metadata_2025 huggingface dataset:
THE PERFORMANCE ANALYSIS OF A 3D MAP EMBEDDED INS/GPS FUSION ALGORITHM FOR SEAMLESS VEHICULAR NAVIGATION IN ELEVATED HIGHWAY ENVIRONMENTS
Authors: Lee Y. H. , Chiang K. W.
Published: August 2012

Abstract. In this study, a 3D Map Matching (3D MM) algorithm is embedded to current INS/GPS fusion algorithm for enhancing the sustainability and accuracy of INS/GPS integration systems, especially the height component. In addition, this study propose an effective solutions to the limitation of current commercial vehicular navigation systems where they fail to distinguish whether the vehicle is moving on the elevated highway or the road under it because those systems don’t have sufficient height resolution. To validate the performance of proposed 3D MM embedded INS/GPS integration algorithms, in the test area, two scenarios were considered, paths under the freeways and streets between tall buildings, where the GPS signal is obstacle or interfered easily. The test platform was mounted on the top of a land vehicle and also systems in the vehicle. The IMUs applied includes SPAN-LCI (0.1 deg/hr gyro bias) from NovAtel, which was used as the reference system, and two MEMS IMUs with different specifications for verifying the performance of proposed algorithm. The preliminary results indicate the proposed algorithms are able to improve the accuracy of positional components in GPS denied environments significantly with the use of INS/GPS integrated systems in SPP mode.
PLEIADES-HR INNOVATIVE TECHNIQUES FOR RADIOMETRIC IMAGE QUALITY COMMISSIONING
Authors: Blanchet G. , Lebeque L. , Fourest S. , Latry C. , Porez-Nadal F. , Lacherade S. , Thiebaut C.
Published: August 2012

Abstract. The first Pleiades-HR satellite, part of a constellation of two, has been launched on December 17, 2011. This satellite produces high resolution optical images. In order to achieve good image quality, Pleiades-HR should first undergo an important 6 month commissioning phase period. This phase consists in calibrating and assessing the radiometric and geometric image quality to offer the best images to end users. This new satellite has benefited from technology improvements in various fields which make it stand out from other Earth observation satellites. In particular, its best-in-class agility performance enables new calibration and assessment techniques. This paper is dedicated to presenting these innovative techniques that have been tested for the first time for the Pleiades- HR radiometric commissioning. Radiometric activities concern compression, absolute calibration, detector normalization, and refocusing operations, MTF (Modulation Transfer Function) assessment, signal-to-noise ratio (SNR) estimation, and tuning of the ground processing parameters. The radiometric performances of each activity are summarized in this paper.
PLEIADES-HR SYSTEM PRODUCTS PERFORMANCE AFTER IN-ORBIT COMMISSIONING PHASE
Authors: Panem C. , Bignalet-Cazalet F. , Baillarin S.
Published: August 2012

Abstract. Launched on 2011, December 16th by the second Soyuz operated in French Guiana, PLEIADES-HR acquired its first high resolution images 3 days after. The PLEIADES program is a space Earth Observation system led by the French Space Agency (CNES), it provides the first european high resolution satellite which will simultaneously acquire in Panchromatic and Multi- Spectral modes 20 km wide images with a 70 cm nadir resolution. Imaging capabilities have been highly optimized in order to acquire, in the same pass, along-track mosaics, stereo pairs and triplets, and multi-targets. Ground segment processes automatically data to ensure operational requirements and quick access to images for the users. Since ground processing capabilities have been taken into account very early in the mission development, it has been possible to relax some costly on-board components requirements, in order to achieve a cost effective on-board/ground compromise. Starting from the PLEIADES system and on board characteristics, this paper first presents an overview of ground segment functional breakdown. Then it focuses more precisely on the different levels of products and associated processing performances. Finally the paper shows how appropriate ground processing systems allowed CNES Image Quality team to assess radiometric and geometric performances during the 6 first months of PLEIADES 1A.
APPLICATION OF MOBILE LIDAR MAPPING FOR DAMAGE SURVEY AFTER GREAT EAST JAPAN EARTHQUAKE
Authors: Ariyasu E. , Koizumi M. , Ikubo M. , Hatake S.
Published: August 2012

Abstract. A massive earthquake of magnitude 9.0 hit off Tohoku region, the east coast of the Japanese main land, on 11 March, 2011. It was one of the historically powerful earthquakes in the world. The earthquake triggered powerful tsunami and broad-scale subsidence, so that, residential areas and infrastructures were catastrophically damaged. After that, it is necessary to renew a new map for reconstruction, such as cadastral map. In the critical situation, Mobile LiDAR Mapping system is efficient to rapidly collect fine data at once and capture more details of terrain features than data from airborne. In this paper, we would like to introduce procured instruments in our company and implemented survey several areas after the event, and suggest how to survey for cadastral map by Mobile LiDAR Mapping System.
USING RELATIVE ORIENTATION CONSTRAINTS TO PRODUCE VIRTUAL IMAGES FROM OBLIQUE FRAMES
Authors: Tommaselli A. M. G. , Moraes M. V. A. , Marcato J. , Caldeira C. R. T. , Lopes R. F. , Galo M.
Published: August 2012

Abstract. Image acquisition systems based on multi-head arrangement of digital cameras are attractive alternatives enabling larger imaging area when compared to a single frame camera. The calibration of this kind of systems can be performed using bundle adjustment with relative orientation stability constraints. The paper will address the details of the steps of the proposed approach for system calibration, image rectification, registration and fusion. Experiments with terrestrial and aerial images acquired with two Fuji FinePix S3Pro cameras were performed. The experiments focused on the assessment of the results of self calibrating bundle adjustment with and without relative orientation constraints and the effects in the registration and fusion when generating virtual images The experiments have shown that the images can be accurately rectified and registered with the proposed approach, achieving residuals smaller than 1 pixel.
A GIS-BASED MULTI-CRITERIA EVALUATION SYSTEM FOR SELECTION OF LANDFILL SITES: a case study from Abu Dhabi, United Arab Emirates
Authors: Issa S. M. , Al Shehhi B.
Published: August 2012

Abstract. Landfill sites receive 92% of total annual solid waste produced by municipalities in the emirate of Abu Dhabi. In this study, candidate sites for an appropriate landfill location for the Abu Dhabi municipal area are determined by integrating geographic information systems (GIS) and multi-criteria evaluation (MCE) analysis. To identify appropriate landfill sites, eight input map layers including proximity to urban areas, proximity to wells and water table depth, geology and topography, proximity to touristic and archeological sites, distance from roads network, distance from drainage networks, and land slope are used in constraint mapping. A final map was generated which identified potential areas showing suitability for the location of the landfill site. Results revealed that 30% of the study area was identified as highly suitable, 25% as suitable, and 45% as unsuitable. The selection of the final landfill site, however, requires further field research.
NON-SPATIAL AND GEOSPATIAL SEMANTIC QUERY OF HEALTH INFORMATION
Authors: Gao S. , Anton F. , Mioc D. , Boley H.
Published: August 2012

Abstract. With the growing amount of health information and frequent outbreaks of diseases, the retrieval of health information is given more concern. Machine understanding of spatial information can improve the interpretation of health data semantics. Most of the current research focused on the non-spatial semantics of health data, using ontologies and rules. Utilizing the spatial component of health data can assist in the understanding of health phenomena. This research proposes a semantic health information query architecture that allows the incorporation of both non-spatial semantics and geospatial semantics in health information integration and retrieval.
WORKING WITH SPATIO-TEMPORAL DATA TYPE
Authors: Raza A.
Published: August 2012

Abstract. Several aspects of spatiotemporal databases have been explored in past decades, ranging from basic data structure to query processing and indexing. But today, operational temporal GIS does not exist. The key impediments have been the complexity of integrating space and time and the lack of standards. OpenGIS standards for simple feature access (spatial type) do exist, but unlike the spatial type, standards for spatiotemporal data type do not exist. This paper explores a new approach to modeling space and time to provide the basis for implementing a temporal GIS. This approach is based on the concept of data types in databases. A data type provides constructors, accessors, and operators. Most commercial and open source databases provide data types to deal with the spatial component of a GIS, called spatial type. Oracle Spatial, DB2 Spatial Extender and Informix Spatial DataBlade, ST_Geometry for PostgreSQL and Oracle from Esri, PostGIS for PostgreSQL, etc., are some examples. This new spatiotemporal data type is called spatiotemporal type (STT). This STT is implemented in PostgreSQL, an open source relational database management system. The STT is an extension of Esri's ST_Geometry type for PostgreSQL, in which each spatial object has a life span. Constructors, accessors, and relational functions are provided to create STT and support spatial, spatiotemporal, and temporal queries. Some functions are extended based on OpenGIS standards for the spatial type. Examples are provided to demonstrate the application of these functions. The paper concludes with limitations and challenges of implementing STT.
AN EFFICIENT ALGORITHM FOR THE CONVEX HULL OF PLANAR SCATTERED POINT SET
Authors: Fu Z. , Lu Y.
Published: August 2012

Abstract. Computing the convex hull of a point set is requirement in the GIS applications. This paper studies on the problem of minimum convex hull and presents an improved algorithm for the minimum convex hull of planar scattered point set. It adopts approach that dividing the point set into several sub regions to get an initial convex hull boundary firstly. Then the points on the boundary, which cannot be vertices of the minimum convex hull, are removed one by one. Finally the concave points on the boundary, which cannot be vertices of the minimum convex hull, are withdrew. Experimental analysis shows the efficiency of the algorithm compared with other methods.
EVALUATING THE NOVEL METHODS ON SPECIES DISTRIBUTION MODELING IN COMPLEX FOREST
Authors: Tu C. H. , Lo N. J. , Chang W. I. , Huang K. Y.
Published: August 2012

Abstract. The prediction of species distribution has become a focus in ecology. For predicting a result more effectively and accurately, some novel methods have been proposed recently, like support vector machine (SVM) and maximum entropy (MAXENT). However, high complexity in the forest, like that in Taiwan, will make the modeling become even harder. In this study, we aim to explore which method is more applicable to species distribution modeling in the complex forest. Castanopsis carlesii (long-leaf chinkapin, LLC), growing widely in Taiwan, was chosen as the target species because its seeds are an important food source for animals. We overlaid the tree samples on the layers of altitude, slope, aspect, terrain position, and vegetation index derived from SOPT-5 images, and developed three models, MAXENT, SVM, and decision tree (DT), to predict the potential habitat of LLCs. We evaluated these models by two sets of independent samples in different site and the effect on the complexity of forest by changing the background sample size (BSZ). In the forest with low complex (small BSZ), the accuracies of SVM (kappa = 0.87) and DT (0.86) models were slightly higher than that of MAXENT (0.84). In the more complex situation (large BSZ), MAXENT kept high kappa value (0.85), whereas SVM (0.61) and DT (0.57) models dropped significantly due to limiting the habitat close to samples. Therefore, MAXENT model was more applicable to predict species’ potential habitat in the complex forest; whereas SVM and DT models would tend to underestimate the potential habitat of LLCs.
RECONSTRUCTION OF BUILDING OUTLINES IN DENSE URBAN AREAS BASED ON LIDAR DATA AND ADDRESS POINTS
Authors: Jarzabek-Rychard M.
Published: August 2012

Abstract. The paper presents a comprehensive method for automated extraction and delineation of building outlines in densely built-up areas. A novel approach to outline reconstruction is the use of geocoded building address points. They give information about building location thus highly reduce task complexity. Reconstruction process is executed on 3D point clouds acquired by airborne laser scanner. The method consists of three steps: building detection, delineation and contours refinement. The algorithm is tested against a data set that presents the old market town and its surroundings. The results are discussed and evaluated by comparison to reference cadastral data.
CLASSIFICATION BY USING MULTISPECTRAL POINT CLOUD DATA
Authors: Liao C. T. , Huang H. H.
Published: August 2012

Abstract. Remote sensing images are generally recorded in two-dimensional format containing multispectral information. Also, the semantic information is clearly visualized, which ground features can be better recognized and classified via supervised or unsupervised classification methods easily. Nevertheless, the shortcomings of multispectral images are highly depending on light conditions, and classification results lack of three-dimensional semantic information. On the other hand, LiDAR has become a main technology for acquiring high accuracy point cloud data. The advantages of LiDAR are high data acquisition rate, independent of light conditions and can directly produce three-dimensional coordinates. However, comparing with multispectral images, the disadvantage is multispectral information shortage, which remains a challenge in ground feature classification through massive point cloud data. Consequently, by combining the advantages of both LiDAR and multispectral images, point cloud data with three-dimensional coordinates and multispectral information can produce a integrate solution for point cloud classification. Therefore, this research acquires visible light and near infrared images, via close range photogrammetry, by matching images automatically through free online service for multispectral point cloud generation. Then, one can use three-dimensional affine coordinate transformation to compare the data increment. At last, the given threshold of height and color information is set as threshold in classification.
PROGRESSIVE DENSIFICATION AND REGION GROWING METHODS FOR LIDAR DATA CLASSIFICATION
Authors: Pérez-García J. L. , Delgado J. , Cardenal J. , Colomo C. , Ureña M. A.
Published: August 2012

Abstract. At present, airborne laser scanner systems are one of the most frequent methods used to obtain digital terrain elevation models. While having the advantage of direct measurement on the object, the point cloud obtained has the need for classification of their points according to its belonging to the ground. This need for classification of raw data has led to appearance of multiple filters focused LiDAR classification information. According this approach, this paper presents a classification method that combines LiDAR data segmentation techniques and progressive densification to carry out the location of the points belonging to the ground. The proposed methodology is tested on several datasets with different terrain characteristics and data availability. In all case, we analyze the advantages and disadvantages that have been obtained compared with the individual techniques application and, in a special way, the benefits derived from the integration of both classification techniques. In order to provide a more comprehensive quality control of the classification process, the obtained results have been compared with the derived from a manual procedure, which is used as reference classification. The results are also compared with other automatic classification methodologies included in some commercial software packages, highly contrasted by users for LiDAR data treatment.
A COMPARISON OF TWO DIFFERENT APPROACHES OF POINT CLOUD CLASSIFICATION BASED ON FULL-WAVEFORM LIDAR DATA
Authors: Wang J.-H. , Li C.-R. , Tang L.-L. , Zhou M. , Li J.-M.
Published: August 2012

Abstract. In this paper, two different point cloud classification approaches were applied based on the full-waveform LiDAR data. At the beginning, based on the full-waveform LiDAR data, we decomposed the backscattered pulse waveform and abstracted each component in the waveform after the pre-processing of noise detection and waveform smoothing. And by the time flag of each component acquired in the decomposition procedure we calculated the three dimension coordination of the component. Then the components’ waveform properties, including amplitude, width and cross-section, were uniformed respectively and formed the Amplitude/Width/Section space. Then two different approaches were applied to classify the points. First, we selected certain targets and trained the parameters, after that, by the supervised classification way we segmented the study area point. On the other hand, we apply the IHSL colour transform to the above space to find a new space, RGB colour space, which has a uniform distinguishability among the parameters and contains the whole information of each component in Amplitude/Width/Section space. Then the fuzzy C-means algorithm is applied to the derived RGB space to complete the LiDAR point classification procedure. By comparing the two different segmentation results, which may of substantial importance for further targets detection and identification, a brief discussion and conclusion were brought out for further research and study.
ULTRAMAP: THE ALL IN ONE PHOTOGRAMMETRIC SOLUTION
Authors: Wiechert A. , Gruber M. , Karner K.
Published: August 2012

Abstract. This paper describes in detail the dense matcher developed since years by Vexcel Imaging in Graz for Microsoft’s Bing Maps project. This dense matcher was exclusively developed for and used by Microsoft for the production of the 3D city models of Virtual Earth. It will now be made available to the public with the UltraMap software release mid-2012. That represents a revolutionary step in digital photogrammetry. The dense matcher generates digital surface models (DSM) and digital terrain models (DTM) automatically out of a set of overlapping UltraCam images. The models have an outstanding point density of several hundred points per square meter and sub-pixel accuracy and are generated automatically. The dense matcher consists of two steps. The first step rectifies overlapping image areas to speed up the dense image matching process. This rectification step ensures a very efficient processing and detects occluded areas by applying a back-matching step. In this dense image matching process a cost function consisting of a matching score as well as a smoothness term is minimized. In the second step the resulting range image patches are fused into a DSM by optimizing a global cost function. The whole process is optimized for multi-core CPUs and optionally uses GPUs if available. UltraMap 3.0 features also an additional step which is presented in this paper, a complete automated true-ortho and ortho workflow. For this, the UltraCam images are combined with the DSM or DTM in an automated rectification step and that results in high quality true-ortho or ortho images as a result of a highly automated workflow. The paper presents the new workflow and first results.
RESEARCH ON THE THREE ANGULAR RESOLUTION OF TERRESTRIAL LASER SCANNING
Authors: Yang R. , Hua X. , Liu J. , Wu H.
Published: August 2012

Abstract. Terrestrial laser scanning technology has been applied more and more widely in the field of Surveying and mapping. Although requirements of the accuracy for different laser scanner survey may differ considerably, spatial resolution is an important aspect, which can be divided into range and angular components. The latter is a focus of this paper and is governed primarily by scanning interval, laser beam width and angle quantisation. An ultimate goal of this research is to derive the relationship and simplified formula between scanning interval and the angular quantisation when the EIFOV(Effective Instantaneous Field of View) is equal to the scanning interval; the relationship and simplified formula of scanning interval and the angular quantisation when the EIFOV is equal to the laser beam width, and the relationship and simplified formula of the theoretical minimum EIFOV and the angular quantisation. Firstly, this paper introduces the EIFOV model and the AMTF(Average Modulation Transfer Function) model. Secondly, the dimensionless AMTF and EIFOV generic model are proposed. Thirdly, the above relathionships are deduced，which are ellipse or hyperbola, and the three simplified formulas are proposed. The simplified formulas have direct significance on the angular resolution's calculation and the scanning interval setting.
ADVANCES OF FLASH LIDAR DEVELOPMENT ONBOARD UAV
Authors: Zhou G. , Yang J. , Li X. , Yang X.
Published: August 2012

Abstract. A small cost-low civilian UAV (Unmanned Aerial Vehicle - UAV) platform usually requests that all carried components should be light in weight, small in volume, and efficient in energy. This paper presents the advance of a pre-mature of flash LiDAR system including laser emitting system, associate with the pulsed voltage technology. A complete laser emitting system, including laser diode, conic lens, alignment, divergence angle, etc., has been designed and implemented. The laser emitting system is first simulated and tested using 3D-Tool software, and then manufactured by an industrial company. In addition, a novel power supply topology based on two coupled coils, pulse generator circuit, and a fast switch, is proposed since several 100 V in voltage, 10-100 A in current, several hundred millisecond in pulse width is needed for flash LiDAR system onboard a small low-cost civilian UAV platform, and the traditional power supply had problems in efficiency and bulk. Finally, laser emitting and the power supply are assembled and tested. The size of laser footprint is 4398.031 mm x 4398.031 mm in x and y axes, respectively, when shitting from a flight height of 300 m, which is close to the theoretic size of 4.5 m x 4.5 m. The difference of 102 mm can meet the requirement of flash LiDAR data collection at a flight height of 300 m. Future work on extensive and on-going investigation and investments for a prototype of flash LiDAR system is drawn up as well.
GENERAL MATHEMATICAL MODEL OF LEAST SQUARES 3D SURFACE MATCHING AND ITS APPLICATION OF STRIP ADJUSTMENT
Authors: Zuo Z. Q. , Liu Z. J. , Zhang L. , Tuermer S.
Published: August 2012

Abstract. Systematic errors in point clouds acquired by airborne laser scanners, photogrammetric methods or other 3D measurement techniques need to be estimated and removed by adjustment procedures. The proposed method estimates the transformation parameters between reference surface and registration surface using a mathematical adjustment model. 3D surface matching is an extension of 2D least squares image matching. The estimation model is a typical Gauss-Markoff model and the goal is minimizing the sum of squares of the Euclidean distances between the contiguous surfaces. Besides the generic mathematical model, we also propose a concept of conjugate points rules which are suitable for special registering applications, and compare it to three typical conjugate points rules. Finally, we explain how this method can be used for the co-registration of real 3D point sets and show co-registration results based on airborne laser scanner data. Concluding results of our experiment suggest that the proposed method has a good performance of 3D surface matching, and the least normal distance rule returns the best result for the strip adjustment of airborne laser altimetry data.
EDGE-BASED REGISTRATION FOR AIRBORNE IMAGERY AND LIDAR DATA
Authors: Chen L. C. , Lo C. Y.
Published: August 2012

Abstract. Aerial imagery and LIDAR points are two important data sources for building reconstruction in a geospatial area. Aerial imagery implies building contours with planimetric features; LIDAR data explicitly represent building geometries using three-dimensional discrete point clouds. Data integration may take advantage of merits from two data sources in building reconstruction and change detection. However, heterogeneous data may contain a relative displacement because of different sensors and the capture time. To reduce this displacement, data registration should be an essential step. Therefore, this investigation proposes an edge-based approach to register these two data sets in three parts: (1) data preprocessing; (2) feature detection; and (3) data registration. The first step rasterizes laser point clouds into a pseudo-grid digital surface model (PDSM), which describes the relief with the original elevation information. The second step implements topological analyses to detect image edges and three-dimensional structure lines from the aerial image and PDSM. These detected features provide the initial positions of building shapes for registration. The third part registers these two data sets in Hough space to compensate for the displacement. Because each building may have prominent geometric structures, the proposed scheme transforms these two groups of edges, and estimates the correspondence by the Hough distribution. The following procedure then iteratively compares two groups of Hough patterns, which are from an aerial image and LIDAR data. This iterative procedure stops when the displacement is within a threshold. The test area is located in Taipei City, Taiwan. DMC system captured the aerial image with 18-cm spatial resolution. The LIDAR data were scanned with a 10-point density per square meter using the Leica ALS50 system. This study proposed a 50 cm spatial resolution of PDSM, which is slightly larger than the point spacing. The experiment selected two buildings to evaluate the performance of the proposed scheme. The manually edited building boundaries from the stereo aerial images are the reference data for validation. Comparisons indicated that the registration procedure could adjust the displacement within 50 cm, which relates to PDSM resolution. These preliminary results also demonstrated the possibility of providing locations for building reconstruction.
RECONSTRUCTION OF SKY ILLUMINATION DOMES FROM GROUND-BASED PANORAMAS
Authors: Coubard F. , Lelégard L. , Brédif M. , Paparoditis N. , Briottet X.
Published: August 2012

Abstract. The knowledge of the sky illumination is important for radiometric corrections and for computer graphics applications such as relighting or augmented reality. We propose an approach to compute environment maps, representing the sky radiance, from a set of ground-based images acquired by a panoramic acquisition system, for instance a mobile-mapping system. These images can be affected by important radiometric artifacts, such as bloom or overexposure. A Perez radiance model is estimated with the blue sky pixels of the images, and used to compute additive corrections in order to reduce these radiometric artifacts. The sky pixels are then aggregated in an environment map, which still suffers from discontinuities on stitching edges. The influence of the quality of estimated sky radiance on the simulated light signal is measured quantitatively on a simple synthetic urban scene; in our case, the maximal error for the total sensor radiance is about 10%.
GESTALT GROUPING ON FAÇADE TEXTURES FROM IR IMAGE SEQUENCES: COMPARING DIFFERENT PRODUCTION SYSTEMS
Authors: Michaelsen E. , Iwaszczuk D. , Hoegner L. , Sirmacek B. , Stilla U.
Published: August 2012

Abstract. The façades of buildings are almost always organized according to Gestalt principles such as good continuation, repetition in similarity, or symmetry etc. Coding such principles in production systems yields a very flexible frame to explore the usefulness of such principles in automatic façade understanding. Capturing images and image sequences of façades in the thermal domain and understanding such data is of importance e.g. for energy saving. In this contribution two different production systems are compared using the same data and interpreter.
PLANE MATCHING WITH OBJECT-SPACE SEARCHING USING INDEPENDENTLY RECTIFIED IMAGES
Authors: Takeda H. , Akamatsu Y. , Minami Y.
Published: August 2012

Abstract. In recent years, the social situation in cities has changed significantly such as redevelopment due to the massive earthquake and large-scale urban development. For example, numerical simulations can be used to study this phenomenon. Such simulations require the construction of high-definition three-dimensional city models that accurately reflect the real world. Progress in sensor technology allows us to easily obtain multi-view images. However, the existing multi-image matching techniques are inadequate. In this paper, we propose a new technique for multi-image matching. Since the existing method of feature searching is complicated, we have developed a rectification method that can be processed independently for each image does not depend on the stereo-pair. The object-space searching method that produces mismatches due to the occlusion or distortion of wall textures on images is the focus of our study. Our proposed technique can also match the building wall surface. The proposed technique has several advantages, and its usefulness is clarified through an experiment using actual images.
A MULTI-VIEW IMAGE MATCHING METHOD FOR FEATURE POINTS BASED ON THE MOVING Z-PLANE CONSTRAINT
Authors: Wang J. , Song W. , Bu F.
Published: August 2012

Abstract. Focusing on the serious occlusion problem in city images, this paper makes full use of the advantage of multi-view image matching, and proposes a reliable multi-view image matching method based on the moving Z-Plane constraint. It supposes a fictitious plane in the object space, and the plane is divided to regular grid cell (small plane element) by a certain interval (≥ image resolution). By moving the plane to different elevation positions, this algorithm makes feature point projection ray in overall images intersect with the plane, and constrains the candidate points by grid cells in the plane. Feature points which come from different images projection ray in the same grid cell on the plane may be regarded as the matching candidates. It selects the images which matching candidate points by gray similarity constraint to avoid the effect from occlusion image. According to the number of projection ray in the grid cell, this algorithm adopts hierarchy matching strategy of "the best candidate will be matched in the first instant", and uses initial matching results as constraint condition in the latter matching process. Finally, the validity of the algorithm proposed in this paper is verified by the experiments using four UltraCamX (UCX) digital aerial images and the algorithm is shown to have reliable matching results.
IMAGE ACQUISITION CONSTRAINTS FOR PANORAMIC FRAME CAMERA IMAGING
Authors: Kauhanen H. , Rönnholm P.
Published: August 2012

Abstract. The paper describes an approach to quantify the amount of projective error produced by an offset of projection centres in a panoramic imaging workflow. We have limited this research to such panoramic workflows in which several sub-images using planar image sensor are taken and then stitched together as a large panoramic image mosaic. The aim is to simulate how large the offset can be before it introduces significant error to the dataset. The method uses geometrical analysis to calculate the error in various cases. Constraints for shooting distance, focal length and the depth of the area of interest are taken into account. Considering these constraints, it is possible to safely use even poorly calibrated panoramic camera rig with noticeable offset in projection centre locations. The aim is to create datasets suited for photogrammetric reconstruction. Similar constraints can be used also for finding recommended areas from the image planes for automatic feature matching and thus improve stitching of sub-images into full panoramic mosaics. The results are mainly designed to be used with long focal length cameras where the offset of projection centre of sub-images can seem to be significant but on the other hand the shooting distance is also long. We show that in such situations the error introduced by the offset of the projection centres results only in negligible error when stitching a metric panorama. Even if the main use of the results is with cameras of long focal length, they are feasible for all focal lengths.
FEATURE MODELLING OF HIGH RESOLUTION REMOTE SENSING IMAGES CONSIDERING SPATIAL AUTOCORRELATION
Authors: Chen Y. X. , Qin K. , Liu Y. , Gan S. Z. , Zhan Y.
Published: August 2012

Abstract. To deal with the problem of spectral variability in high resolution satellite images, this paper focuses on the analysis and modelling of spatial autocorrelation feature. The semivariograms are used to model spatial variability of typical object classes while Getis statistic is used for the analysis of local spatial autocorrelation within the neighbourhood window determined by the range information of the semivariograms. Two segmentation experiments are conducted via the Fuzzy C-Means (FCM) algorithm which incorporates both spatial autocorrelation features and spectral features, and the experimental results show that spatial autocorrelation features can effectively improve the segmentation quality of high resolution satellite images.
FAST POWER LINE DETECTION AND LOCALIZATION USING STEERABLE FILTER FOR ACTIVE UAV GUIDANCE
Authors: Liu Y. , Mejias L. , Li Z.
Published: August 2012

Abstract. In this paper we present a fast power line detection and localisation algorithm as well as propose a high-level guidance architecture for active vision-based Unmanned Aerial Vehicle (UAV) guidance. The detection stage is based on steerable filters for edge ridge detection, followed by a line fitting algorithm to refine candidate power lines in images. The guidance architecture assumes an UAV with an onboard Gimbal camera. We first control the position of the Gimbal such that the power line is in the field of view of the camera. Then its pose is used to generate the appropriate control commands such that the aircraft moves and flies above the lines. We present initial experimental results for the detection stage which shows that the proposed algorithm outperforms two state-of-the-art line detection algorithms for power line detection from aerial imagery.
RESEARCH ON THE IMPROVED IMAGE DODGING ALGORITHM BASED ON MASK TECHNIQUE
Authors: Yao F. , Hu H. , Wan Y.
Published: August 2012

Abstract. The remote sensing image dodging algorithm based on Mask technique is a good method for removing the uneven lightness within a single image. However, there are some problems with this algorithm, such as how to set an appropriate filter size, for which there is no good solution. In order to solve these problems, an improved algorithm is proposed. In this improved algorithm, the original image is divided into blocks, and then the image blocks with different definitions are smoothed using the low-pass filters with different cut-off frequencies to get the background image; for the image after subtraction, the regions with different lightness are processed using different linear transformation models. The improved algorithm can get a better dodging result than the original one, and can make the contrast of the whole image more consistent.
ON OBJECT EXTRACTION USING AIRBORNE LASER SCANNER DATA AND DIGITAL IMAGES FOR 3D MODELLING
Authors: Nakano K. , Chikatsu H.
Published: August 2012

Abstract. Airborne laser scanners are effective at extracting the micro topography or ground surface under trees, which cannot be detected by aerial photogrammetry, and are suitable for use in many applications, such as city modelling, DTM generation, monitoring electrical power lines, and detection of forest areas. The most remarkable aspect of these systems is their ability to acquire the 3D coordinates of huge object points in real-time. There are many studies on object extraction using point clouds from airborne laser scanner data, where the shape of an object depends on the density of a point. However, this is generally used for rough shapes or fitted geometric shapes. It is difficult to reconstruct detailed object shapes without many edge points, even if high-density point clouds are obtained. On the other hand, it is possible to acquire detailed object edges from digital camera images if the digital camera is equipped with an airborne laser scanner system. The procedures investigated in this paper for improving rough object shapes using airborne laser scanner data are as follows. Firstly, camera calibration is performed to integrate point clouds and digital images by simultaneous adjustment, such as by bundle adjustment with self-calibration using distance data taken directly from airborne laser scanner data. Secondly, the rough 3D object shape is extracted from the point cloud using normal vectors. Moreover, visualization of normal vectors is used for operator interpretation. Thirdly, the rough 3D object shape is converted into the image coordinates of multiple images by a collinearity condition. The 2D coordinates of detailed image shapes are acquired using characteristic image quantities from around the rough shape. Finally, the detailed 3D shape is computed using the spatial intersection of the 2D coordinates of detailed shapes and the orientation parameters. This paper describes fundamental studies for extracting object shapes for 3D modelling using airborne laser scanner data and digital images.
DETECTION AND EVALUATION OF SKIN DISORDERS BY ONE OF PHOTOGRAMMETRIC IMAGE ANALYSIS METHODS
Authors: Güçin M. , Patias P. , Altan M. O.
Published: August 2012

Abstract. Abnormalities on skin may vary from simple acne to painful wounds which affect a person's life quality. Detection of these kinds of disorders in early stages, followed by the evaluation of abnormalities is of high importance. At this stage, photogrammetry offers a non-contact solution to this concern by providing geometric highly accurate data. Photogrammetry, which has been used for firstly topographic purposes, in virtue of terrestrial photogrammetry became useful technique in non-topographic applications also (Wolf et al., 2000). Moreover the extension of usage of photogrammetry, in parallel with the development in technology, analogue photographs are replaced with digital images and besides digital image processing techniques, it provides modification of digital images by using filters, registration processes etc. Besides, photogrammetry (using same coordinate system by registration of images) can serve as a tool for the comparison of temporal imaging data. The aim of this study is to examine several digital image processing techniques, in particular the digital filters, which might be useful to determine skin disorders. In our study we examine affordable to purchase, user friendly software which needs neither expertise nor pre-training. Since it is a pre-work for subsequent and deeper studies, Adobe Photoshop 7.0 is used as a present software. In addition to that Adobe Photoshop released a DesAcc plug-ins with CS3 version and provides full compatibility with DICOM (Digital Imaging and Communications in Medicine) and PACS (Picture Archiving and Communications System) that enables doctors to store all medical data together with relevant images and share if necessary.
ORFEO, THE PLEIADES ACCOMPANIMENT PROGRAM AND ITS USERS THEMATIC COMMISSIONING
Authors: Tinel C. , Grizonnet M. , Fontannaz D. , de Boissezon H. , Giros A.
Published: August 2012

Abstract. ORFEO, the PLEIADES Accompaniment Program, was set up by CNES, the French Space Agency, to prepare, accompany and promote the use and the exploitation of the images acquired by this Very High Resolution optical sensor. It was initiated in 2004 and will last until the end of the first year of the satellite life (launched in December 2011) . The Thematic part of the ORFEO accompaniment program covers a large range of applications, and aims at specifying and validating products and services required by users. An in-depth work of user needs assessments in eight thematic domains (sea and coastline, risks and humanitarian aid, cartography and urban planning, geophysical hazards, hydrology, forestry, agriculture and defence) has given rise to a large number of feasibility studies from 2006 to 2011. The Methodological Part of the ORFEO accompaniment program aims at preparing the use and exploitation of these submetric images. CNES decided to develop Orfeo Toolbox (OTB), an open source library capitalising the methodological know-how as a set of image processing and algorithmic components. Among other, OTB provides a number of heavily documented image processing functionalities such as filtering, feature extraction, segmentation, classification, change detection, 3D extraction, GIS links,.... As a conclusion to the ORFEO program, the PLEIADES Users Thematic Commissioning (UTC) started three months after the satellite launch and will last until mid 2013. It covers a large number of specific interest ORFEO sites, on which PLEIADES images are being intensively acquired and processed. These ORFEO sites have been chosen according to the expectations expressed by the users in terms of their interest for dedicated thematic, their geographic location and their multi-thematic content. This paper presents the ORFEO program achievements (thematic and methodology) and the organisation of the Users Thematic Commissioning (sites, studies). The paper is illustrated with some examples of multi-thematic studies, lead through ORFEO, covering a large range of applications, and aiming at validating value added products and services provided to end users from PLEIADES imagery.
LINE-BASED MULTI-IMAGE MATCHING FOR FAÇADE RECONSTRUCTION
Authors: Teo T. A. , Kao C. H.
Published: August 2012

Abstract. This research integrates existing LOD 2 building models and multiple close-range images for façade structural lines extraction. The major works are orientation determination and multiple image matching. In the orientation determination, Speeded Up Robust Features (SURF) is applied to extract tie points automatically. Then, tie points and control points are combined for block adjustment. An object-based multi-images matching is proposed to extract the façade structural lines. The 2D lines in image space are extracted by Canny operator followed by Hough transform. The role of LOD 2 building models is to correct the tilt displacement of image from different views. The wall of LOD 2 model is also used to generate hypothesis planes for similarity measurement. Finally, average normalized cross correlation is calculated to obtain the best location in object space. The test images are acquired by a nonmetric camera Nikon D2X. The total number of image is 33. The experimental results indicate that the accuracy of orientation determination is about 1 pixel from 2515 tie points and 4 control points. It also indicates that line-based matching is more flexible than point-based matching.
PHOTOGRAMMETRIC MODEL BASED METHOD OF AUTOMATIC ORIENTATION OF SPACE CARGO SHIP RELATIVE TO THE INTERNATIONAL SPACE STATION
Authors: Blokhinov Y. B. , Chernyavskiy A. S. , Zheltov S. Y.
Published: August 2012

Abstract. The technical problem of creating the new Russian version of an automatic Space Cargo Ship (SCS) for the International Space Station (ISS) is inseparably connected to the development of a digital video system for automatically measuring the SCS position relative to ISS in the process of spacecraft docking. This paper presents a method for estimating the orientation elements based on the use of a highly detailed digital model of the ISS. The input data are digital frames from a calibrated video system and the initial values of orientation elements, these can be estimated from navigation devices or by fast-and-rough viewpoint-dependent algorithm. Then orientation elements should be defined precisely by means of algorithmic processing. The main idea is to solve the exterior orientation problem mainly on the basis of contour information of the frame image of ISS instead of ground control points. A detailed digital model is used for generating raster templates of ISS nodes; the templates are used to detect and locate the nodes on the target image with the required accuracy. The process is performed for every frame, the resulting parameters are considered to be the orientation elements. The Kalman filter is used for statistical support of the estimation process and real time pose tracking. Finally, the modeling results presented show that the proposed method can be regarded as one means to ensure the algorithmic support of automatic space ships docking.
EVALUATION MODEL FOR PAVEMENT SURFACE DISTRESS ON 3D POINT CLOUDS FROM MOBILE MAPPING SYSTEM
Authors: Aoki K. , Yamamoto K. , Shimamura H.
Published: August 2012

Abstract. This paper proposes a methodology to evaluate the pavement surface distress for maintenance planning of road pavement using 3D point clouds from Mobile Mapping System (MMS). The issue on maintenance planning of road pavement requires scheduled rehabilitation activities for damaged pavement sections to keep high level of services. The importance of this performance-based infrastructure asset management on actual inspection data is globally recognized. Inspection methodology of road pavement surface, a semi-automatic measurement system utilizing inspection vehicles for measuring surface deterioration indexes, such as cracking, rutting and IRI, have already been introduced and capable of continuously archiving the pavement performance data. However, any scheduled inspection using automatic measurement vehicle needs much cost according to the instruments’ specification or inspection interval. Therefore, implementation of road maintenance work, especially for the local government, is difficult considering costeffectiveness. Based on this background, in this research, the methodologies for a simplified evaluation for pavement surface and assessment of damaged pavement section are proposed using 3D point clouds data to build urban 3D modelling. The simplified evaluation results of road surface were able to provide useful information for road administrator to find out the pavement section for a detailed examination and for an immediate repair work. In particular, the regularity of enumeration of 3D point clouds was evaluated using Chow-test and F-test model by extracting the section where the structural change of a coordinate value was remarkably achieved. Finally, the validity of the current methodology was investigated by conducting a case study dealing with the actual inspection data of the local roads.
A NOVEL APPROACH FOR SEGMENTATION OF AIRBORNE LASER SCANNING POINT CLOUD LOCATED ON ROOF STRUCTURE
Authors: Fan H.
Published: August 2012

Abstract. This paper is addressed to an approach for segmenting airborne laser scanning point cloud. It aims to detect and cluster point cloud of an input roof into several segments that are corresponding to plane patches of the roof. The algorithm is developed based on the assumption that every non-flat roof can be decomposed into a set of gabled and/or hipped roof. The process detects roof ridges at first, and then detects points along each roof ridge. The experiments shows high efficiency and low error segmentation of the algorithm.