Search icon
Arrow left icon
All Products
Best Sellers
New Releases
Books
Videos
Audiobooks
Learning Hub
Newsletters
Free Learning
Arrow right icon
Learning OpenCV 3 Application Development

You're reading from  Learning OpenCV 3 Application Development

Product type Book
Published in Dec 2016
Publisher Packt
ISBN-13 9781784391454
Pages 310 pages
Edition 1st Edition
Languages
Author (1):
Samyak Datta Samyak Datta
Profile icon Samyak Datta

Table of Contents (16) Chapters

Learning OpenCV 3 Application Development
Credits
About the Author
About the Reviewer
www.PacktPub.com
Preface
Laying the Foundation Image Filtering Image Thresholding Image Histograms Image Derivatives and Edge Detection Face Detection Using OpenCV Affine Transformations and Face Alignment Feature Descriptors in OpenCV Machine Learning with OpenCV Command-line Arguments in C++

AdaBoost learning


In the section, Haar features, we stated that there are 180,000 rectangle (Haar) features associated with each image sub-window. Even though each feature can be computed very efficiently with the help of an integral image, using this complete set is prohibitively expensive. In order to circumvent this predicament, a neat little trick was applied. It is reasonable to expect that not all of the 18,000 theoretically possible features within each sub-window are equally important. What if we could sample this huge set of features that we have, and for each sub-window, select a reasonably small subset of features that can help us with our classification task? If we do that, we would have a very small number of these features combined to form an effective classifier.

This is the main idea behind the technique known as AdaBoost learning. In fact, AdaBoost goes a step further and learns multiple such classifiers-each of which learn on a subset of the features. These classifiers are...

lock icon The rest of the chapter is locked
Register for a free Packt account to unlock a world of extra content!
A free Packt account unlocks extra newsletters, articles, discounted offers, and much more. Start advancing your knowledge today.
Unlock this book and the full library FREE for 7 days
Get unlimited access to 7000+ expert-authored eBooks and videos courses covering every tech area you can think of
Renews at $15.99/month. Cancel anytime}