Table of Contents Partial Derivatives and Jacobian Matrix in Stochastic Gradient Descent Basics of Vector Calculus Vectors Differentiation of Univariate Functions What Are Derivatives? Derivatives of Common Functions Central Difference Formula Partial Derivatives and Gradients Multivariate Functions Partial Derivatives Gradients,…

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 how to use TensorFlow’s GradientTape function to create custom training loops to train Keras models. Today’s tutorial was inspired by a question I received by PyImageSearch reader Timothy: Hi Adrian, I just read your…

In this tutorial, you will learn how to visualize class activation maps for debugging deep neural networks using an algorithm called Grad-CAM. We’ll then implement Grad-CAM using Keras and TensorFlow. While deep learning has facilitated unprecedented accuracy in image classification,…

I’m going to start today’s blog post by asking a series of questions which will then be addressed later in the tutorial: What are image convolutions? What do they do? Why do we use them? How do we apply them?…

Between myself and my father, Jemma, the super-sweet, hyper-active, extra-loving family beagle may be the most photographed dog of all time. Since we got her as a 8-week old puppy, to now, just under three years later, we have accumulated…

Today’s post is a followup to a previous (extremely popular) article on detecting barcodes in images using Python and OpenCV. In the previous post we explored how to detect and find barcodes in images. But today we are going to…

UPDATE: The introduction to this post may seen a little “out there”. For some context, I had just finished watching the South Park Black Friday episodes prior to writing this post so I definitely had some inspiration regarding zombie shoppers,…

A few days ago, I got an email from a PyImageSearch reader asking about circle detection. See below for the gist: Hey Adrian, Love your blog. I saw your post on detecting rectangles/squares in images, but I was wondering, how…