Automating image interpretation requires applying a combination of imageprocessing, cartographic information, and domain- and task-specific knowledge-based reasoning to a particular task. A group of projects in agric...
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Automating image interpretation requires applying a combination of imageprocessing, cartographic information, and domain- and task-specific knowledge-based reasoning to a particular task. A group of projects in agriculture and forestry for which spatial and general domain knowledge were used to guide and improve image segmentation and patternrecognition is reviewed. The nature of the knowledge used in these projects is found to be either spatial information which can be coded into a GIS (geographic information system) or metaknowledge about processes and methodologies at the image-processing or cartographic levels. A trimodal diagram is shown for evaluating explicitly the different levels of knowledge and the flow of control between them. A trimodal scheme is presented that shows the relationships between the iconic processes, the cartographic (or symbolic) processes and the knowledge processes. It is shown that these processes form a hierarchy of levels moving from more concrete to more abstract processes. The flow of control in a typical task begins with the lower levels and migrates to the higher levels as the task proceeds. A software system for uniting the various components is outlined, and the present state of its implementation is discussed. It is noted that an integrated database which directly supports all three levels is needed for the system to work efficiently.
The Multiport Array Receptor (MAR), a system which combines optical sensing with integrated focal-plane processing capabilities, is described. Its central element is a photosensor array with hexagonal tesselation and ...
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The Multiport Array Receptor (MAR), a system which combines optical sensing with integrated focal-plane processing capabilities, is described. Its central element is a photosensor array with hexagonal tesselation and complex peripheral selection logic which provides parallel analog readout over prescribed areas. An external computing module performs real-time spatial convolution at multiple resolutions while a closed-loop microprogrammed controller addresses regions of interest and supervises communication between the camera and the host computer. This integrated image sensor and processor implements programmed sequences of instruction primitives and yields a complete state description of each processed pixel. It is capable of automatic edge tracking and returns lists of connected pixels.
A set of adaptive transforms is defined which emphasises atypical features in an image. The transforms emphasise features such as regions of atypical grey level, boundaries, or unusual multispectral properties. The re...
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A set of adaptive transforms is defined which emphasises atypical features in an image. The transforms emphasise features such as regions of atypical grey level, boundaries, or unusual multispectral properties. The result of the transforms is a new image in which the difference between an atypical feature and the rest of the image has been enhanced.< >
Research work dealing with some of the problems in computer vision (CV) and image understanding (IU) is described. Attention is given to progress in CV and IU involving active range finders, passive stereo sensing, 3D...
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Research work dealing with some of the problems in computer vision (CV) and image understanding (IU) is described. Attention is given to progress in CV and IU involving active range finders, passive stereo sensing, 3D reconstruction, 3D scene analysis, dynamic scene analysis, automatic knowledge acquisition for model- and strategy-based systems, and autonomous vision systems.< >
A novel method is presented for the registration of a SPOT satellite image against a Seasat synthetic aperture radar (SAR) image. An edge following technique is proposed. It is adapted to very noisy images such as SAR...
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A novel method is presented for the registration of a SPOT satellite image against a Seasat synthetic aperture radar (SAR) image. An edge following technique is proposed. It is adapted to very noisy images such as SAR images. It is shown that, by the use of a multiresolution method, a directional graph can be constructed which gives a clearer definition of the equivalence between edge following and optimal path search on a graph. A hypothesis-testing approach, also based on a multiresolution method, is proposed to solve the registration problem. The hypotheses are drawn from scale space representations in order to maintain a low complexity. These hypotheses are then tested by a chamfer distance map. By the combination of scale space representation and the chamfer matching method, a very robust and fast registration results.< >
The Multiport Array Receptor (MAR), a system which combines optical sensing with integrated focal-plane processing capabilities, is described. Its central element is a photosensor array with hexagonal tesselation and ...
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The Multiport Array Receptor (MAR), a system which combines optical sensing with integrated focal-plane processing capabilities, is described. Its central element is a photosensor array with hexagonal tesselation and complex peripheral selection logic which provides parallel analog readout over prescribed areas. An external computing module performs real-time spatial convolution at multiple resolutions while a closed-loop microprogrammed controller addresses regions of interest and supervises communication between the camera and the host computer. This integrated image sensor and processor implements programmed sequences of instruction primitives and yields a complete state description of each processed pixel. It is capable of automatic edge tracking and returns lists of connected pixels.< >
A number of architectures which combine efficient iconic and symbolic processing are reviewed. An approach which enhances the structure of the 2D mesh while still retaining that structure is suggested. The deficiencie...
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A number of architectures which combine efficient iconic and symbolic processing are reviewed. An approach which enhances the structure of the 2D mesh while still retaining that structure is suggested. The deficiencies of the mesh, in its usual form, in terms of symbolic processing are taken as indications of how the enhancement should proceed. The authors identify three orthogonal properties (processor power, processor autonomy, and interprocessor connectivity) which are open to manipulation. On the basis of a number of generic operations, both iconic and symbolic, the effect of varying each of these parameters is examined with emphasis on the requirements for sequences of operations to execute efficiently. An attempt is made to evaluate the cost-effectiveness of the various possibilities.< >
A dynamically generated panoramic representation for route recognition by a mobile robot is presented. The strategies employed are route description from experience and route recognition by visual information. In the ...
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A dynamically generated panoramic representation for route recognition by a mobile robot is presented. The strategies employed are route description from experience and route recognition by visual information. In the description phase, panoramic representation, a representation of scenes along a route, is proposed. It is obtained by scanning scenes sideways along the route, which provides rich information, such as a 2-D projection of scenes called panoramic view, a path-oriented 2-1/2-D sketch, and a path description. The continuous panoramic view is more efficient in processing than integrating discrete views into a complete route model. In the recognition phase, the robot matches the panoramic representation from incoming images with that memorized in the previous scan so that it can locate and orient itself in autonomous navigation. Since the panoramic view covers a wide field of view, one can achieve reliable matching using a coarse-to-fine method, starting from a very coarse level.< >
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