In this post, we will learn how to read, write and display videos in OpenCV. Before we do that, allow me a digression into a bit of history of video capture. On June 15, 1898, in Palo Alto, California, a remarkable experiment was conducted to determine whether a galloping horse ever had all … [Read more...]
Get OpenCV Build Information ( getBuildInformation )
In this tutorial, we will introduce a quick way to check your OpenCV build settings. If you have ever compiled or installed OpenCV, you know it can be compiled with an overwhelming number of options. For example, when installed on MacOS with Homebrew, OpenCV3 has the following options. … [Read more...]
Automatic Red Eye Remover using OpenCV (C++ / Python)
In this tutorial, we will learn how to remove red eyes from a photo completely automatically. Just thinking about this problem of red-eye removal brings back memories from my childhood. I grew up in small towns in India where not every family in my middle-class neighborhood had a camera. My … [Read more...]
Head Pose Estimation using OpenCV and Dlib
In this tutorial we will learn how to estimate the pose of a human head in a photo using OpenCV and Dlib. In many applications, we need to know how the head is tilted with respect to a camera. In a virtual reality application, for example, one can use the pose of the head to render the right view … [Read more...]
Live CV : A Computer Vision Coding Application
In this article I will present Live CV, a computer vision coding application, and describe a few of it's implementation details along the way. … [Read more...]
Rotation Matrix To Euler Angles
In this post I will share code for converting a 3x3 rotation matrix to Euler angles and vice-versa. 3D rotations matrices can make your head spin. I know it is a bad pun but truth can sometimes be very punny! A rotation matrix has three degrees of freedom, and mathematicians have exercised … [Read more...]
Average Face : OpenCV ( C++ / Python ) Tutorial
In this tutorial we will learn how to create an average face using OpenCV ( C++ / Python ). Most people would agree that the woman in Figure 1 is pretty. Can you guess her ethnicity ? Why is her skin flawless ? Well, she is not real. She is not completely virtual either. Her face is the average … [Read more...]
Face Morph Using OpenCV — C++ / Python
In this tutorial we will learn how to morph one face into another using OpenCV. I have chosen to use the photos of the top three American Presidential candidates, but this is not a political post and I have no political agenda. And yes, that is the prettiest picture of Donald Trump I … [Read more...]
Homography Examples using OpenCV ( Python / C ++ )
The Tower of Babel, according to a mythical tale in the Bible, was humans' first engineering disaster. The project had all the great qualities of having a clear mission, lots of man power, no time constraint and adequate technology ( bricks and mortar ). Yet it failed spectacularly because God … [Read more...]
Blob Detection Using OpenCV ( Python, C++ )
This tutorial explains simple blob detection using OpenCV. What is a Blob ? A Blob is a group of connected pixels in an image that share some common property ( E.g grayscale value ). In the image above, the dark connected regions are blobs, and the goal of blob detection is to identify and mark … [Read more...]