Contour Detection using OpenCV (Python/C++)

Knowing where an object is in an image is called localization in computer vision. Using contour detection, we can detect the borders of objects, and therefore, localize them easily. Importantly, contour detection could be the very first step for many interesting applications such as image foreground extraction, simple image segmentation, detection and recognition. The official OpenCV documentation says: "The contours are a useful tool for shape analysis and object detection and recognition." Let us discuss contour detection using OpenCV. In this post, we are going to learn about contours and contour detection using OpenCV. Not only the theory, we will also cover a complete hands-on coding in both Python and C programming languages to have a first hand experience of contour detection using OpenCV. You can build some really cool applications using contour detection and OpenCV. The following outlines interesting ones. Now that we gave an idea of the content of this article, let us also see what we are going to cover in this tutorial. When we join all the points on the boundary of an object, we get a contour.