Tag: c++

CamCal 003 Camera Transformation

Highlights: In this post we will talk about camera calibration technique, and rigid body transformations. You will also see how translation and rotation works. Tutorial Overview: Intro Geometric camera calibration Rigid body transformations´╗┐ Notation Rotation 1. Intro In this post, we’re going to talk about extrinsic camera calibration and here is the model that we are going to use. In particular, we had a system where we had a center of projection (COP) that was…
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Harris Corner Detector 013

OpenCV #013 Harris Corner Detector – Theory

Highlights: In this post we will learn about Harris Corner Detector and how can we use this method to detect corners. We will give a brief overview how this method works, but we’ll not go so seriously with mathematics. We promise ­čÖé What is Harris Corner Detector? In many computer vision and machine learning applications we need some feature points which we will track or which will assist us to compare and detect objects or…
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CamCal #012 Stereo Geometry Code

Highlights: In this post we will finish our mini series on stereo geometry. We will wrap some things up, and go through the code related to this. In the last few posts we talked about stereo geometry. We covered many concepts, from basic stuff, such as essential matrix and epipolar lines to the fundamental matrix. Here, we will present a code that can help us to compute them. Tutorial Overview: Detecting key points (SIFT, SURF,…
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CamCal 002 Weak Perspective

Highlights: In this post we will talk about how human vision can be tricked with a Perspective Projection model, and we will present one new model, which is called Weak Perspective. Tutorial Overview: Human vision Weak perspective 1. Human vision Humans are very sensitive to this structure of parallel lines and what they convey to us. Probably most of you have seen this Muller-Lyer illusion. Which one of these lines is longer? And you probably…
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OpenCV #010 Circle Detection Using Hough Transform

Highlights: In this post we will learn about analysing a given image to find circles detected in that image. Tutorial Overview: Intro Detecting Circles with Hough Hough Transform for Circles Code 1. Intro In the previous post, we saw how we can detect and find lines on images using Hough Transform. Now let’s move to something just a little bit more complicated, circles. Let’s start with the equation of a circle: $$ ( x_{i}-a )^{2}+(…
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