Book Image

Building Computer Vision Projects with OpenCV 4 and C++

By : David Millán Escrivá, Prateek Joshi, Vinícius G. Mendonça, Roy Shilkrot
Book Image

Building Computer Vision Projects with OpenCV 4 and C++

By: David Millán Escrivá, Prateek Joshi, Vinícius G. Mendonça, Roy Shilkrot

Overview of this book

OpenCV is one of the best open source libraries available and can help you focus on constructing complete projects on image processing, motion detection, and image segmentation. This Learning Path is your guide to understanding OpenCV concepts and algorithms through real-world examples and activities. Through various projects, you'll also discover how to use complex computer vision and machine learning algorithms and face detection to extract the maximum amount of information from images and videos. In later chapters, you'll learn to enhance your videos and images with optical flow analysis and background subtraction. Sections in the Learning Path will help you get to grips with text segmentation and recognition, in addition to guiding you through the basics of the new and improved deep learning modules. By the end of this Learning Path, you will have mastered commonly used computer vision techniques to build OpenCV projects from scratch. This Learning Path includes content from the following Packt books: •Mastering OpenCV 4 - Third Edition by Roy Shilkrot and David Millán Escrivá •Learn OpenCV 4 By Building Projects - Second Edition by David Millán Escrivá, Vinícius G. Mendonça, and Prateek Joshi
Table of Contents (28 chapters)
Title Page
Copyright and Credits
About Packt
Contributors
Preface
Index

Understanding background subtraction


Background subtraction is very useful in video surveillance. Basically, the background subtraction technique performs really well in cases where we have to detect moving objects in a static scene. How is this useful for video surveillance? The process of video surveillance involves dealing with constant data flow. The data stream keeps coming in and we need to analyze it to recognize any suspicious activity. Let's consider the example of a hotel lobby. All the walls and furniture have a fixed location. If we build a background model, we can use it to identify suspicious activity in the lobby. We are taking advantage of the fact that the background scene remains static (which happens to be true in this case). This helps us avoid any unnecessary computational overhead. As the name indicates, this algorithm works by detecting and assigning each pixel of an image to two classes, either the background (assumed static and stable) or the foreground, and subtracting...