Book Image

Learning OpenCV 3 Application Development

By : Samyak Datta
Book Image

Learning OpenCV 3 Application Development

By: Samyak Datta

Overview of this book

Computer vision and machine learning concepts are frequently used in practical computer vision based projects. If you’re a novice, this book provides the steps to build and deploy an end-to-end application in the domain of computer vision using OpenCV/C++. At the outset, we explain how to install OpenCV and demonstrate how to run some simple programs. You will start with images (the building blocks of image processing applications), and see how they are stored and processed by OpenCV. You’ll get comfortable with OpenCV-specific jargon (Mat Point, Scalar, and more), and get to know how to traverse images and perform basic pixel-wise operations. Building upon this, we introduce slightly more advanced image processing concepts such as filtering, thresholding, and edge detection. In the latter parts, the book touches upon more complex and ubiquitous concepts such as face detection (using Haar cascade classifiers), interest point detection algorithms, and feature descriptors. You will now begin to appreciate the true power of the library in how it reduces mathematically non-trivial algorithms to a single line of code! The concluding sections touch upon OpenCV’s Machine Learning module. You will witness not only how OpenCV helps you pre-process and extract features from images that are relevant to the problems you are trying to solve, but also how to use Machine Learning algorithms that work on these features to make intelligent predictions from visual data!
Table of Contents (16 chapters)
Learning OpenCV 3 Application Development
Credits
About the Author
About the Reviewer
www.PacktPub.com
Preface

Chapter 3. Image Thresholding

As part of our computer vision and image processing journey so far, we have essentially seen two different types of operation. The first and simpler ones were the grayscale transformations, where the output intensity value of a pixel depends only upon the intensity of the corresponding pixel in the input image. The second, slightly more complex form of processing that we saw is the image filtering operations, where the output intensity depends on a neighborhood rather than a single intensity value.

During our discourse on image filtering in Chapter 2, Image Filtering, we laid emphasis on how the aforementioned two approaches differ. However, there is some sense in which grayscale transformations and image filtering operations are alike. Algorithms belonging to both these classes produce grayscale images. Irrespective of the complexity of implementation, all the algorithms that we have discussed up to this point take a grayscale image as input and produce another...