Book Image

Machine Learning with R - Second Edition

By : Brett Lantz
Book Image

Machine Learning with R - Second Edition

By: Brett Lantz

Overview of this book

Table of Contents (19 chapters)
Machine Learning with R Second Edition
Credits
About the Author
About the Reviewers
www.PacktPub.com
Preface
Index

Example – performing OCR with SVMs


Image processing is a difficult task for many types of machine learning algorithms. The relationships linking patterns of pixels to higher concepts are extremely complex and hard to define. For instance, it's easy for a human being to recognize a face, a cat, or the letter "A", but defining these patterns in strict rules is difficult. Furthermore, image data is often noisy. There can be many slight variations in how the image was captured, depending on the lighting, orientation, and positioning of the subject.

SVMs are well-suited to tackle the challenges of image data. Capable of learning complex patterns without being overly sensitive to noise, they are able to recognize visual patterns with a high degree of accuracy. Moreover, the key weakness of SVMs—the black box model representation—is less critical for image processing. If an SVM can differentiate a cat from a dog, it does not matter much how it is doing so.

In this section, we will develop a model...