OpenCV Tutorials

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. A dataset with images in various color spaces is useful to…

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…

In this tutorial, you will learn about smoothing and blurring with OpenCV. We will cover the following blurring operations Simple blurring (cv2.blur) Weighted Gaussian blurring (cv2.GaussianBlur) Median filtering (cv2.medianBlur) Bilateral blurring (cv2.bilateralFilter) By the end of this tutorial, you’ll be…

In this tutorial, you will learn how to use OpenCV and the cv2.threshold function to apply basic thresholding and Otsu thresholding. A dataset for this topic enables us to understand the effect of different thresholding techniques on different types of…

In this tutorial, you will learn my tips, suggestions, and best practices to achieve high face detection accuracy with OpenCV and dlib. We’ve covered face detection four times on the PyImageSearch blog: Face detection with OpenCV and Haar cascades Face…

In this tutorial, you will learn about OpenCV Haar Cascades and how to apply them to real-time video streams. Haar cascades, first introduced by Viola and Jones in their seminal 2001 publication, Rapid Object Detection using a Boosted Cascade of…

In this tutorial, you will learn how to perform face detection with OpenCV and Haar cascades. This guide, along with the next two, were inspired by an email I received from PyImageSearch reader, Angelos: Hi Adrian, I’ve been an avid…

In this tutorial, you will learn how to perform multi-template matching with OpenCV. Last week you discovered how to utilize OpenCV and the cv2.matchTemplate function for basic template matching. The problem with this approach is that it could only detect…