Digital Image Processing using OpenCV (Python & C++) Highlights: In this post, we will learn about the Canny Edge Detector. In the last few posts, we explained why edges are important for better understanding of the image, and how we can use Laplacian and Sobel filter to detect them. At the places where this method does not give good results, we can use the Canny Edge Detector and dramatically improve the obtained results. Tutorial Overview:…
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Highlights: In this post we will continue working on Harris Corner Detector. In the previous post we presented the basic idea behind this algorithm, and here we will wrap this up and show how this method works in OpenCV. Tutorial Overview: Interpreting the Second Moment Matrix Interpreting the Eigenvalues Harris Corner Response Function Harris Detector Algorithm Code 1. Interpreting the Second Moment Matrix Let’s first consider the case, where the gradient at every point in…
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Digital Image Processing using OpenCV (Python & C++) Highlights: In this post we will learn about Thresholding. This method is essential in many computer vision applications. The purpose of this post is to show and benchmark performance of several different approaches, and also to provide you with the necessary knowledge to implement it. Tutorial Overview: Thresholding Simple thresholding Adaptive thresholding Otsu’s Binarization 1. Thresholding In the last post we explained why edges are important for…
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Digital Image Processing using OpenCV (Python & C++) Highlights: In this post, we will learn what Sobel operator and an image gradient are. We will show how to calculate the horizontal and vertical edges as well as edges in general. What is the most important element in the image? Edges! See below. Tutorial Overview: What is the gradient? Finite difference. Discrete gradient. Sobel Operator. 1. What is the Gradient? Let’s talk about differential operators. When…
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Digital Image Processing using OpenCV (Python & C++) Highlights: In this post, we will learn how to apply and use an Averaging and a Gaussian filter. We will also explain the main differences between these filters and how they affect the output image. What does make a good filter? This is a million dollar question. Tutorial Overview: Averaging filter Gaussian filter 1. Averaging filter What does make a good filter? So, let’s start with a…
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