摘要 :
A partial edge drawing (PED) of a graph is a variation of a node-link diagram. PED draws a link, which is a partial visual representation of an edge, and reduces visual clutter of the node-link diagram. However, more time is requi...
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A partial edge drawing (PED) of a graph is a variation of a node-link diagram. PED draws a link, which is a partial visual representation of an edge, and reduces visual clutter of the node-link diagram. However, more time is required to read a PED to infer undrawn parts. The authors propose a morphing edge drawing (MED), which is a PED that changes with time. In MED, links morph between partial and complete drawings; thus, a reduced load for estimation of undrawn parts in a PED is expected. Herein, a formalization of MED is shown based on a formalization of PED. Then, requirements for the scheduling of morphing are specified. The requirements inhibit morphing from crossing and shorten the overall time for morphing the edges. Moreover, an algorithm for a scheduling method implemented by the authors is illustrated and the effectiveness of PED from a reading time viewpoint is shown through an experimental evaluation.
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摘要 :
A partial edge drawing (PED) of a graph is a variation of a node-link diagram. PED draws a link, which is a partial visual representation of an edge, and reduces visual clutter of the node-link diagram. However, more time is requi...
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A partial edge drawing (PED) of a graph is a variation of a node-link diagram. PED draws a link, which is a partial visual representation of an edge, and reduces visual clutter of the node-link diagram. However, more time is required to read a PED to infer undrawn parts. The authors propose a morphing edge drawing (MED), which is a PED that changes with time. In MED, links morph between partial and complete drawings; thus, a reduced load for estimation of undrawn parts in a PED is expected. Herein, a formalization of MED is shown based on a formalization of PED. Then, requirements for the scheduling of morphing are specified. The requirements inhibit morphing from crossing and shorten the overall time for morphing the edges. Moreover, an algorithm for a scheduling method implemented by the authors is illustrated and the effectiveness of PED from a reading time viewpoint is shown through an experimental evaluation.
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摘要 :
Morphing edge drawing (MED), a graph drawing technique, is a dynamic extension of partial edge drawing (PED), where partially drawn edges (stubs) are repeatedly stretched and shrunk by morphing. Previous experimental evaluations h...
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Morphing edge drawing (MED), a graph drawing technique, is a dynamic extension of partial edge drawing (PED), where partially drawn edges (stubs) are repeatedly stretched and shrunk by morphing. Previous experimental evaluations have shown that the reading time with MED may be shorter than that with PED. The morphing scheduling method limits visual clutter by avoiding crossings between stubs. However, as the number of intersections increases, the overall morphing cycle tends to lengthen in this method, which is likely to have a negative effect on the reading time. In this paper, improved scheduling methods are presented to address this issue. The first method shortens the duration of a single cycle by overlapping a part of the current cycle with the succeeding one. The second method duplicates every morph by the allowable number of times in one cycle. The third method permits a specific number of simultaneous crossings per edge. The effective performances of these methods are demonstrated through experimental evaluations.
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摘要 :
We consider the problem of drawing a graph where edges are represented by smooth curves between the associated nodes. Previously curved edges were drawn as splines defined by carefully calculated control points. We present a compl...
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We consider the problem of drawing a graph where edges are represented by smooth curves between the associated nodes. Previously curved edges were drawn as splines defined by carefully calculated control points. We present a completely different approach where finding an edge is reduced to solving a differential equation. This approach allows to represent the graph drawing aesthetics directly, even the most complex ones denoting the dependencies among the paths.
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摘要 :
We consider the problem of drawing a graph where edges are represented by smooth curves between the associated nodes. Previously curved edges were drawn as splines defined by carefully calculated control points. We present a compl...
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We consider the problem of drawing a graph where edges are represented by smooth curves between the associated nodes. Previously curved edges were drawn as splines defined by carefully calculated control points. We present a completely different approach where finding an edge is reduced to solving a differential equation. This approach allows to represent the graph drawing aesthetics directly, even the most complex ones denoting the dependencies among the paths.
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摘要 :
Applying photogrammetry to generate 3D scenes and objects is a common task. To achieve complete and high-quality 3D reconstruction, successful detection and matching of geometric edge features are crucial to retrieving the geometr...
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Applying photogrammetry to generate 3D scenes and objects is a common task. To achieve complete and high-quality 3D reconstruction, successful detection and matching of geometric edge features are crucial to retrieving the geometric shapes of scenes or objects. Appropriate implementations of edge detection and edge matching will not only enhance the geometric information but also contribute to gaining great benefit when assisting in 3D reconstruction tasks. To this end, this paper specifically chooses Canny and Edge Drawing operators, two commonly applied tools, to investigate their differences in the integrity of edge description and the accuracy of edge positions under varied Gaussian blur that mainly causes offset of edges. The generalized Hough Transform is applied to edge matching following the edge detection by Canny and Edge Drawing, respectively. The main contribution of this work is to quantify the performance of edge detection and matching of the two operators by the effective indicators and to gain deep insight into the sensitivities of image blur effect. On the other hand, this research would help in establishing an effective and efficient workflow to support the relevant image edge detection and matching tasks.
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摘要 :
Applying photogrammetry to generate 3D scenes and objects is a common task. To achieve complete and high-quality 3D reconstruction, successful detection and matching of geometric edge features are crucial to retrieving the geometr...
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Applying photogrammetry to generate 3D scenes and objects is a common task. To achieve complete and high-quality 3D reconstruction, successful detection and matching of geometric edge features are crucial to retrieving the geometric shapes of scenes or objects. Appropriate implementations of edge detection and edge matching will not only enhance the geometric information but also contribute to gaining great benefit when assisting in 3D reconstruction tasks. To this end, this paper specifically chooses Canny and Edge Drawing operators, two commonly applied tools, to investigate their differences in the integrity of edge description and the accuracy of edge positions under varied Gaussian blur that mainly causes offset of edges. The generalized Hough Transform is applied to edge matching following the edge detection by Canny and Edge Drawing, respectively. The main contribution of this work is to quantify the performance of edge detection and matching of the two operators by the effective indicators and to gain deep insight into the sensitivities of image blur effect. On the other hand, this research would help in establishing an effective and efficient workflow to support the relevant image edge detection and matching tasks.
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Canny Edge Detector is the most widely used operator for edge detection. The problem with Canny is that it outputs a binary edge map, where an edge pixel (edgel) is marked (e.g., its value in the edge map is 255) and a non-edge pi...
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Canny Edge Detector is the most widely used operator for edge detection. The problem with Canny is that it outputs a binary edge map, where an edge pixel (edgel) is marked (e.g., its value in the edge map is 255) and a non-edge pixel is unmarked (e.g., its value in the edge map is 0). A typical binary edge map is of low quality, consisting of gaps, notch-like structures, ragged and multi-pixel wide edgels. To clean up Canny's binary edge maps, fill up one pixel-wide gaps between the edgels, and to return the map as a set of edge segments, each of which is a one-pixel wide, contiguous chain of pixels, we employ the Smart Routing (SR) algorithm from our recently proposed Edge Segment Detection Algorithm, the Edge Drawing (ED). The proposed algorithm, called Canny Smart Routing (CannySR), runs Canny to obtain a binary edge map, and uses the Canny edgels as anchors for SR to convert them to edge segments. The produced edge segments can then be used in many applications such as line, arc, circle, ellipse, corner detection and other similar higher level object detection applications. We qualitatively evaluate the effectiveness of the proposed algorithm on some sample images and conclude that CannySR visibly improves the modal quality of Canny's binary edge maps although ED seems to produce the best results.
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摘要 :
Canny Edge Detector is the most widely used operator for edge detection. The problem with Canny is that it outputs a binary edge map, where an edge pixel (edgel) is marked (e.g., its value in the edge map is 255) and a non-edge pi...
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Canny Edge Detector is the most widely used operator for edge detection. The problem with Canny is that it outputs a binary edge map, where an edge pixel (edgel) is marked (e.g., its value in the edge map is 255) and a non-edge pixel is unmarked (e.g., its value in the edge map is 0). A typical binary edge map is of low quality, consisting of gaps, notch-like structures, ragged and multi-pixel wide edgels. To clean up Canny's binary edge maps, fill up one pixel-wide gaps between the edgels, and to return the map as a set of edge segments, each of which is a one-pixel wide, contiguous chain of pixels, we employ the Smart Routing (SR) algorithm from our recently proposed Edge Segment Detection Algorithm, the Edge Drawing (ED). The proposed algorithm, called Canny Smart Routing (CannySR), runs Canny to obtain a binary edge map, and uses the Canny edgels as anchors for SR to convert them to edge segments. The produced edge segments can then be used in many applications such as line, arc, circle, ellipse, corner detection and other similar higher level object detection applications. We qualitatively evaluate the effectiveness of the proposed algorithm on some sample images and conclude that CannySR visibly improves the modal quality of Canny's binary edge maps although ED seems to produce the best results.
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摘要 :
At its most basic, object-space edge detection iterates through all polygonal edges in each mesh to find those edges that satisfy one or more edge tests. Those that do are expanded and rendered, while the remainders are ignored. T...
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At its most basic, object-space edge detection iterates through all polygonal edges in each mesh to find those edges that satisfy one or more edge tests. Those that do are expanded and rendered, while the remainders are ignored. These 3D edges, and their resulting accuracy and customizability, set object-space methods apart from all other categories of edge detection. The speed and memory limitations of iterating through all polygonal edges in each mesh each frame has inspired optimization research. In this paper, we explore methods to calculate object-space edges utilizing programmable GPU technologies, including OpenCL. The OpenCL methods explored allow for a significant reduction in calculation quantity. Some also provide a reduction in rendering artifacts and memory usage over previous GPU techniques. Unfortunately, most uses of OpenCL for edge detection results in slower performance than shader-based techniques, though variations and optimizations may reduce this disadvantage in the future.
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