Questions tagged [edge-detection]
The edge-detection tag has no usage guidance.
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Vertex detection
Consider a 2-dimensional polygon with unknown vertices $V_1, \dots, V_n \in \mathbb{R}^2$. Given a random set of points $p_1,\dots, p_m \in \mathbb{R}^2$ lying approximately on the perimeter of such a ...
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What are some good examples of post-processing edge detection?
I'm trying to implement a post-processing pass to detect silhouette-edges from depth data.
(by silhouette-edge of a triangles mesh I mean the triangle edges shared by a front and a back-facing ...
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HalfEdge: How to get list of all faces from one face
I need to, starting from one face, iterate over the rest of the faces until I reach the first facet. For this I can use twin, start, end or other info of halfedges, faces, vertex. That is, I need to ...
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Half-Edge Data Structure with holes
I am trying to implement next/prev of edges in half-edge data structure. But I ran into this question. If there are two holes with a common vertex, will the closed loop of the edges run as in the ...
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Are there algorithms besides Canny edge detection that can create consistent width edges?
Sobel edge detection is pretty much the quintessential way to get edges out of an image. It however suffers from certain quirks.
One example is, because it's gradient, based certain surfaces exhibit ...
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Which method for detecting edges of white object on white background?
I would like to segment picture of cloths in order to remove the background. The pictures come from online retailers, they usually have an homogeneous white background.
Using Canny edge detector ...
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Rounding a corner formed by Arc and Line
Given shapes like these, which contain just Arcs and lines, I want to round all its corners with certain radius. I know the vertices of the lines & arcs these shapes.
I can round the corners of a ...
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Why does this edge detect show different results for the same color combinations?
I'm researching highlighting accessible color contrast via filter operations. I have a test screenshot of SRGB hex values compared with WCAG's official contrast algorithm:
I converted it to its ...
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Is it better to blur the input or output of an edge detection shader for noise reduction?
To reduce noise of edge detection the norm seems like it is to apply a blur. However, is it generally better to apply the blur to the input of the edge detection. The input in my case being the depth ...
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GLSL - Merge two textures
I would like to display arbitrary 3d meshes with black edges (black outline, black ridges, etc.). Thereby I have created two different textures: One color texture and one anti-aliased edge texture.
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Sobel edge detection line thickness
My goal is to implement an edge detection algorithmus that is capable to find edges of arbitrary 3d meshes. I want to find the edges by detecting normal discontinuities. Furthermore, I want the edges ...
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OpenGL GLSL - Sobel Edge Detection Filter
With respect to this topic I've successfully implemented the Sobel Edge Detection filter in GLSL. Here is the fragment shader code of the filter:
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How would I create a virtual cabling system?
I am trying to devise a GUI system that functions as a virtual patchbay, as seen in something like Logic Studio's environment editor, or seen in virtual synthesizers that use virtual patchcables.
I'm ...
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Controlling Sobel edge thickness
I'm using a Sobel filter to draw an outline in a shader. How do I control its thickness? Here's my outlining code:
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OpenGL - Detection of edges
I'd like to load arbitrary meshes and draw thick black lines along the edges to get a toon-shading like look.
I managed to draw a black silhouette around the objects by using the stencil buffer. You ...
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How to crop with edge-detection using imagemagick [closed]
Let's say I have an image of an object against a white background. I want to crop so that the image fills the available space.
This takes 10px off:
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How can I detect edges between different colours of the same brightness?
I'm looking for an algorithm that can identify edges across which colour is changing sharply, rather than just finding changes in brightness.
Is this just a matter of using a different colour space ...