In many engineering applications, it is necessary to calculate the min-area encasing box of a circumscription. In this paper, an algorithm for generating the min-area rectangle encasing box, based on revolving angle, ...In many engineering applications, it is necessary to calculate the min-area encasing box of a circumscription. In this paper, an algorithm for generating the min-area rectangle encasing box, based on revolving angle, is investigated and hence put forward. The algorithm computes the areas of the outer rectangular bounds of a closed contour in different revolving angles θ by dispersing approach where 0< θ < π/2 because of the axial symmetry. It is very simple, straight forward and highly efficient. The complexity of its computing time reaches O(n·k ). Practical applications suggest its usefulness and efficiency.展开更多
A method to detect airports in large space-borne synthetic aperture radar(SAR)imagery is studied.First,the large SAR imagery is segmented according to amplitude characteristics using maximum a posteriori(MAP)estimator...A method to detect airports in large space-borne synthetic aperture radar(SAR)imagery is studied.First,the large SAR imagery is segmented according to amplitude characteristics using maximum a posteriori(MAP)estimator based on the heavytailed Rayleigh model.The attention is then paid on the object of interest(OOI)extracted from the large images.The minimumarea enclosing rectangle(MER)of OOI is created via a rotating calipers algorithm.The projection histogram(PH)of MER for OOI is then computed and the scale and rotation invariant feature for OOI are extracted from the statistical characteristics of PH.A support vector machine(SVM)classifier is trained using those feature parameters and the airport is detected by the SVM classifier and Hough transform.The application in space-borne SAR images demonstrates the effectiveness of the proposed method.展开更多
文摘In many engineering applications, it is necessary to calculate the min-area encasing box of a circumscription. In this paper, an algorithm for generating the min-area rectangle encasing box, based on revolving angle, is investigated and hence put forward. The algorithm computes the areas of the outer rectangular bounds of a closed contour in different revolving angles θ by dispersing approach where 0< θ < π/2 because of the axial symmetry. It is very simple, straight forward and highly efficient. The complexity of its computing time reaches O(n·k ). Practical applications suggest its usefulness and efficiency.
文摘A method to detect airports in large space-borne synthetic aperture radar(SAR)imagery is studied.First,the large SAR imagery is segmented according to amplitude characteristics using maximum a posteriori(MAP)estimator based on the heavytailed Rayleigh model.The attention is then paid on the object of interest(OOI)extracted from the large images.The minimumarea enclosing rectangle(MER)of OOI is created via a rotating calipers algorithm.The projection histogram(PH)of MER for OOI is then computed and the scale and rotation invariant feature for OOI are extracted from the statistical characteristics of PH.A support vector machine(SVM)classifier is trained using those feature parameters and the airport is detected by the SVM classifier and Hough transform.The application in space-borne SAR images demonstrates the effectiveness of the proposed method.
