A fast and robust type of unsupervised multispectral texture segmentation method with unknown number of classes is presented. Single decorrelated monospectral texture factors are represented by four local autoregressi...
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ISBN:
(纸本)3540288333
A fast and robust type of unsupervised multispectral texture segmentation method with unknown number of classes is presented. Single decorrelated monospectral texture factors are represented by four local autoregressive random field models recursively evaluated for each pixel and for each spectral band. The segmentation algorithm is based on the underlying Gaussian mixture model and starts with an over segmented initial estimation which is adaptively modified until the optimal number of homogeneous texture segments is reached. The performance of the presented method is extensively tested on the Prague segmentation benchmark using nineteen most frequented segmentation criteria.
Due to the complexity and non-regularity of tree shapes, traditional digital photogrammetry using stereo matching method is difficult to obtain the accurate tree height, This fact therefore limits the application of t...
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ISBN:
(纸本)0819460079
Due to the complexity and non-regularity of tree shapes, traditional digital photogrammetry using stereo matching method is difficult to obtain the accurate tree height, This fact therefore limits the application of the aerial digital photogrammetry technology in the power line survey. This paper presents a method of tree height extraction from large viewing aerial image using the knowledge of segmented tree crown. This method is based on a rough digital surface model (DSM) of tree crowns and the exterior orientation of the image. The basic steps of this method is that the DSM is first used to find the region of interest in the image based on the exterior orientation, and then the edges of the distinct trees or branches are extracted using image segmentation technology. An algorithm that uses both the rough DSM height information and exterior orientation data to calculate the accurate heights of the segmented trees or branches is presented. The algorithm assumes that most of the trees are upright, and the projection in the large viewing angle images of the crown and branches can therefore be used to calculate their heights relative to the averaged DSM height. Hence, the accurate height of the trees around the rough DSM can be refined. Some experimental results are given with the image captured from multi-angular imaging system mounted on a helicopter in which a Position and Orientation System (POS) is onboard to record the exterior element of the cameras. The experimental results demonstrated that this algorithm can largely improve the accuracy of tree height extraction. The application in power line monitoring system is promising.
An image enhancement algorithm based on illuminance-reflectance model is proposed for improving the visual quality of digital images captured under insufficient and/or non-uniform lighting conditions. The paper presen...
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Hyperspectral applications in remotesensing are often focused on determining the so-called spectral signatures, i.e., the reflectances of materials present in the scene (endmembers) and the corresponding abundance fr...
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This paper describes a fast and effective component grouping algorithm for some layout analysis problems of textual document images. Based on an empirical function, it discovers neighborhood relations at the component...
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Improved target detection, reduced false alarm rates, and enhanced timeliness are critical to meeting the requirements of current and future military missions. We present a new approach to target detection, based on a...
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Object boundary extraction from binary images is important for many applications, e.g., image vectorization, automatic interpretation of images containing segmentation results, printed and handwritten documents and dr...
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Object boundary extraction from binary images is important for many applications, e.g., image vectorization, automatic interpretation of images containing segmentation results, printed and handwritten documents and drawings, maps, and AutoCAD drawings. Efficient and reliable contour extraction is also important for patternrecognition due to its impact on shape-based object characterization and recognition. The presented contour tracing and component labeling algorithm produces dilated (sub-pixel) contours associated with corresponding regions. The algorithm has the following features: (1) it always produces non-intersecting, non-degenerate contours, including the case of one-pixel wide objects;(2) it associates the outer and inner (i.e., around hole) contours with the corresponding regions during the process of contour tracing in a single pass over the image;(3) it maintains desired connectivity of object regions as specified by 8-neighbor or 4-neighbor connectivity of adjacent pixels;(4) it avoids degenerate regions in both background and foreground;(5) it allows an easy augmentation that will provide information about the containment relations among regions;(6) it has a time complexity that is dominantly linear in the number of contour points. This early component labeling (contour-region association) enables subsequent efficient object-based processing of the image information.
remote color printing, where printing plate images are sent to remote printing factories by digital communication and printed there, necessitates remote color proofing. High quality color proofs should be output at th...
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remote color printing, where printing plate images are sent to remote printing factories by digital communication and printed there, necessitates remote color proofing. High quality color proofs should be output at the printing sites. However, the moiré phenomenon occurs when the printing plate image is output using a proof printer with a different printing resolution from the original, and thus a resized half-tone image is used as a proof. This work analyzes the moiré phenomenon, and shows that the resizing does not necessarily cause the moiré phenomenon if the image has gray levels, the binarizalion causes a halftone dot size shift, and that the dot size modulation leads to the moiré phenomenon. Based on this understanding, a new imageprocessing algorithm to reallocate halftone dots, which can minimize the moiré phenomenon, is proposed. Experiments successfully show the usefulness of the algorithm.
Landuse classification is an important problem in the remotesensing field. It can be used in a wide range of applications. In this paper, we propose a hybrid method fusing edges and regions information for the landus...
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Landuse classification is an important problem in the remotesensing field. It can be used in a wide range of applications. In this paper, we propose a hybrid method fusing edges and regions information for the landuse classification of multispectral images. It mainly includes the steps of image pre-processing, initial segmentation and region merging. Especially, a novel spatial mean shift procedure is proposed so that some information can be extracted and used in the successive steps. Aiming at the multispectral images processing, we also design a band weighting strategy that give a proper weight to each band adoptively according to the region to be processed. Experimental results on the Landsat TM and ETM+ images validate the performance of the proposed method.
On the basis of the rigorous theories of the digital photogrammetry and the latest research achievements in computer vision and imageprocessingpatternrecognition, it is studied for three dimensional(3-D) reconstruc...
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On the basis of the rigorous theories of the digital photogrammetry and the latest research achievements in computer vision and imageprocessingpatternrecognition, it is studied for three dimensional(3-D) reconstruction of irregular industrial sheetmetal parts by using the projector and CCD camera in this paper. As the surface of sheetmetal parts is short of the applicable texture for image matching, it is designed that structured light from the projector is projected onto the surface of sheetmetal parts as it were put on an available texture artificially. Supposed that the image acquired from CCD camera is the left image and the suppositional image from the projector is the right image. Then the image acquired from CCD camera is made edge detection, in which the extracted curves are made curve matching with the suppositional lines from the projector. While made fully use of the feature of the right image obtained from the projector and collinearity equations, the spacial point coordinates on the surface of the sheetmetal parts are obtained quickly by space intersection. Then 3-D reconstruction of the sheetmetal parts is completed after merging all the models. The untouched method which has high efficiency and strong flexibility can be successfully adapted to reconstruct various kinds of shapes and some soft objects.
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