Search results for "Digital pictures"

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Computation of the area in the discrete plane: Green’s theorem revisited

2017

International audience; The detection of the contour of a binary object is a common problem; however, the area of a region, and its moments, can be a significant parameter. In several metrology applications, the area of planar objects must be measured. The area is obtained by counting the pixels inside the contour or using a discrete version of Green's formula. Unfortunately, we obtain the area enclosed by the polygonal line passing through the centers of the pixels along the contour. We present a modified version of Green's theorem in the discrete plane, which allows for the computation of the exact area of a two-dimensional region in the class of polyominoes. Penalties are introduced and …

Binary Objectcontour detectionPolyominoComputationGeometry0102 computer and information sciences02 engineering and technology01 natural sciencesconnectednessPick's theoremsymbols.namesake0202 electrical engineering electronic engineering information engineeringPick's theoremElectrical and Electronic EngineeringGreen's theoremMathematicsDigital picturesPixelMathematical analysisImage segmentationAtomic and Molecular Physics and OpticsComputer Science Applications[SPI.TRON]Engineering Sciences [physics]/Electronics010201 computation theory & mathematics[INFO.INFO-TI]Computer Science [cs]/Image Processing [eess.IV]Binary datasymbols[SPI.OPTI]Engineering Sciences [physics]/Optics / Photonic020201 artificial intelligence & image processingpolyominoesGreen's theorem
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Canopy Architecture Appraisal by Fractal Dimension of 'Flordastar' Peach Trees Grafted onto Different Rootstocks

2007

The objective of this research was to evaluate the modification of canopy architecture of ''Flordastar'' peach (Prunus persica L. Batsch) grafted onto rootstocks with different vigour, by the use of fractal dimension (D). The hypothesis was that different vigour rootstocks are able to modify the complexity of the branching pattern and that this effect can be assessed by a geometric parameter such as the fractal dimension (D) of the 2D projection of tree branching structure. The observations were carried out in a four-year-old experimental orchard of cv. ''Flordastar'' peach trees grafted onto Ishtara, Barrier, GF677 and MrS 2/5 rootstocks. On digital pictures of leafless, dormant peach tree…

The objective of this research was to evaluate the modification of canopy architecture of ''Flordastar'' peach (Prunus persica L. Batsch) grafted onto rootstocks with different vigour by the use of fractal dimension (D). The hypothesis was that different vigour rootstocks are able to modify the complexity of the branching pattern and that this effect can be assessed by a geometric parameter such as the fractal dimension (D) of the 2D projection of tree branching structure. The observations were carried out in a four-year-old experimental orchard of cv. ''Flordastar'' peach trees grafted onto Ishtara Barrier GF677 and MrS 2/5 rootstocks. On digital pictures of leafless dormant peach trees the tree skeleton was manually depicted by an image analysis software to measure total length and angles of insertion of branches. Bitmaps of the skeleton were then subjected to a specific software (FDCALC) able to calculate D by the "box counting" method. To account for the error introduced by analyzing a three dimensional structure with its 2D projection measurements were done on two images per tree taken from two different viewing angles. Results are shown in relation to tree vigour of the scion/stock combination. Fractal dimension was related to the vigour ranking of the graft combinations tested. In particular vigorous scion/stock combinations showed the highest D.HorticultureCanopy architectureHorticultureRootstockFractal dimensionMathematics
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