OpenCV Tutorials

In this tutorial, we’ll learn about a step-by-step implementation and utilization of OpenCV’s Contour Approximation. When I first chanced upon the concept of Contour Approximation, the first question that hit me was: Why? Throughout my journey in Machine Learning and…

In this tutorial, you will learn about image gradients and how to compute Sobel gradients and Scharr gradients using OpenCV’s cv2.Sobel function. Image gradients are a fundamental building block of many computer vision and image processing routines. We use gradients…

In this tutorial, you will learn about adaptive thresholding and how to apply adaptive thresholding using OpenCV and the cv2.adaptiveThreshold function. Last week, we learned how to apply both basic thresholding and Otsu thresholding using the cv2.threshold function. When applying…

In this tutorial, you will learn how to perform edge detection using OpenCV and the Canny edge detector. Previously, we discussed image gradients and how they are one of the fundamental building blocks of computer vision and image processing. Today,…

In this tutorial, you will learn how to implement face recognition using the Eigenfaces algorithm, OpenCV, and scikit-learn. Our previous tutorial introduced the concept of face recognition — detecting the presence of a face in an image/video and then subsequently…

In this tutorial, you will learn how to perform face recognition using Local Binary Patterns (LBPs), OpenCV, and the cv2.face.LBPHFaceRecognizer_create function. In our previous tutorial, we discussed the fundamentals of face recognition, including: The difference between face detection and face…

In this tutorial, you will learn how to compute image histograms using OpenCV and the cv2.calcHist function. Histograms are prevalent in nearly every aspect of computer vision. We use grayscale histograms for thresholding. We use histograms for white balancing. We…

In this tutorial, you will learn about color spaces in OpenCV, the cv2.cvtColor function, and the importance of lighting conditions/environments when building a computer vision and image processing pipeline. To illustrate the importance of lighting conditions, I’d like to start…

In this tutorial, you will learn about applying morphological operations with OpenCV. The morphological operations we’ll be covering include: Erosion Dilation Opening Closing Morphological gradient Black hat Top hat (also called “White hat”) These image processing operations are applied to…