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Questions tagged [canny-edge-detector]

Use for questions about the Canny edge detector

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MatLab-Finding error in hough line transform

Can I calculate the number of error in Hough Line Transform using MatLab? I did Hough Line Transform process from Canny Edge Detection, but it is unable to detect all the lines. Thanks.
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How can I improve the Canny edge detection code?

I have converted this Matlab code for Canny edge detection into C# given that the Matlab version gives out a good output. The output from Matlab code is as follows: And my C# version's outputs are ...
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Approach for determining which cells of a pill box are empty using opencv+python

I am trying to use opencv and python to determine which cells of a pillbox has pills in it (see picture 1). My original approach was: Detect edges using canny Draw lines using hough transform find ...
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Perona Malik Noise Estimator using Canny

In Perona and Malik, they state: a histogram of the absolute values of the gradient throughout the image was computed, and K was set equal to the ...
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detecting edge direction using Julia-language

Let say we have following image: made with following Julia-code: ...
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fitting curves to contours with OpenCV and Python

The above image is an example of a lightbox, with some vessels on top. Overall goal is: to find the middle points of the vessels to mark the area of the disk, enclosed by each vessel What I want ...
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Getting rid of Canny outliers

I have been using the Canny edge detection function in OpenCV to detect the edge of an elliptic annulus (light object, dark background). In theory there should be two edges. However, it sometimes does ...
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Lane detection and tracking using B-snake?

I am truly sorry if my question sounds little bit stupid, but I am getting stuck at this part for a long time. I am currently working for my final year project of lane detection for curved road using ...
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What's the best technique to determine if the contents of two images are the same?

I need to run comparisons on the output of hundreds of frames of simple 3D-rendered characters. Perceptually, many of the frames are exact duplicates. Based on this, I assumed something like a ...
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Why Is the Canny Edge Detection Used Instead of Sobel / Prewitt Edge Detection Before Hough Transformation?

I know that for the Hough Transform to work on an image, it needs to be a binary image. To convert from a grayscale image, an edge detection algorithm should be employed. I notice that people always ...
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Canny non-max suppression intro

I have rich experience signal-processing, but haven't touched image processing since my happy university days... so: Working on a side project, I need to enhance ridges (continuous lines) in a 2D ...
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Edge following using Hough transform

I am trying to improve an edge following algorithm developed by some students who did a project at my work. The algorithm is supposed to make a robot follow a line with the use of a camera. Their ...
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Influence of image size to edge detection in OpenCV

I need to scan an image in OpenCV and obtain the lines. For this I use the canny edge detector and then the propabilistic Hough transform, with which I actually get the lines. The problem now is that ...
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Is the Canny algorithm enough for creating a feature descriptor image for input to an SVM?

I retrieve contours from images by using the Canny algorithm. Is this enough preprocessing to have a descriptor image for input into an SVM to find similarities? Do I need other features like ...
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Edge detection gives pixel ids, why?

This questions is in conjugation with this one here! Canny edge detector gives ids of pixels in an image. Not the locations of the edges. To be specific, after all it should be an edge between two ...
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Could you describe the effects for varying different parameters of a canny edge detector?

Last couple of questions touched upon Canny edge detector What are the limitations of a Canny edge detector? and Best way of segmenting veins in leaves? The basic outline of the algorithm is as ...