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

Using an SVM as a gender classifier


Now that we have seen how to implement a generic SVM classifier using OpenCV/C++, in this section, we outline the steps to use SVM for the gender classification project that we have been working on.

If you noticed in the example that we discussed in the last section, the training data that we loaded was 2-dimensional and had 10 data points. In the previous chapter, we discussed the fact that we are going to represent our faces using the 531-dimensional uniform pattern LBP histogram descriptor. This means that each data point (face) will be represented using 531-dimensions. These values (the feature vector corresponding to the representation of a face) are usually read into the source code through text files. This means that we design our program to accept two files as input, one holding the feature vectors of the faces in the training data set and the other for the test data.

So essentially, this means that we want the feature descriptors of all our face...