The words used in the book are easy to understand and the authors did a good job presenting the technical details.
The source code - ansi C (c99) - is well written and the example are downloadable for free; OpenCV library is an OpenSource project - by intel corporation.
from the authors
This book introduces you to computer vision and demonstrates how you can quickly build applications that enable computers to "see" and make decisions based on the data. Computer vision is everywhere -- in security systems, manufacturing inspection systems, medical image analysis, Unmanned Aerial Vehicles, and more. It helps robot cars drive by themselves, stitches Google maps and Google Earth together, checks the pixels on your laptop's LCD screen, and makes sure the stitches in your shirt are OK.