iOS Application Development with OpenCV 3

Joseph Howse

• Publisher: Packt Publishing
• Year: 2016
• eBook ISBN: 9781785289491
• Edition: 1
• Topic: Computer Science
• Subtopic: Programming Mobile Devices
• Index: Computer Science

Create four mobile apps and explore the world through photography and computer vision

About This Book

• Efficiently harness iOS and OpenCV to capture and process high-quality images at high speed
• Develop photographic apps and augmented reality apps quickly and easily
• Detect, recognize, and morph faces and objects

Who This Book Is For

If you want to do computational photography and computer vision on Apple's mobile devices, then this book is for you. No previous experience with app development or OpenCV is required. However, basic knowledge of C++ or Objective-C is recommended.

What You Will Learn

• Use Xcode and Interface Builder to develop iOS apps
• Obtain OpenCV's standard modules and build extra modules from source
• Control all the parameters of the iOS device's camera
• Capture, save, and share photos and videos
• Analyze colors, shapes, and textures in ordinary and specialized photographs
• Blend and compare images to create special photographic effects and augmented reality tools
• Detect faces and morph facial features
• Classify coins and other objects

In Detail

iOS Application Development with OpenCV 3 enables you to turn your smartphone camera into an advanced tool for photography and computer vision. Using the highly optimized OpenCV library, you will process high-resolution images in real time. You will locate and classify objects, and create models of their geometry. As you develop photo and augmented reality apps, you will gain a general understanding of iOS frameworks and developer tools, plus a deeper understanding of the camera and image APIs.

After completing the book's four projects, you will be a well-rounded iOS developer with valuable experience in OpenCV.

Style and approach

The book is practical, creative, and precise. It shows you the steps to create and customize five projects that solve important problems for beginners in mobile app development and computer vision. Complete source code and numerous visual aids are included in each chapter. Experimentation is an important part of the book. You will use computer vision to explore the real world, and then you will refine the projects based on your findings.

iOS Application Development with OpenCV 3

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Table of Contents

iOS Application Development with OpenCV 3

Credits

About the Author

Acknowledgments

About the Reviewer

www.PacktPub.com

eBooks, discount offers, and more

Why subscribe?

Preface

What this book covers

What you need for this book

Who this book is for

Conventions

Reader feedback

Customer support

Downloading the example code

Downloading the color images of this book

Errata

Piracy

Questions

1. Setting Up Software and Hardware

Setting up Apple's developer tools

Setting up the OpenCV framework

Getting the prebuilt framework with standard modules

Building the framework from source with extra modules

Making the extra modules optional in our code

Developing a minimal application

Creating the project

Adding files to the project

Configuring the project

Laying out an interface

Writing the code

Connecting an interface element to the code

Building and running the application

Distributing to testers and customers

Finding documentation and support

Understanding the camera and setting up photographic accessories

Lights

Tripods and other stabilization

Lens attachments

Summary

2. Capturing, Storing, and Sharing Photos

Planning a photo sharing application

Configuring the project

Adding frameworks

Specifying the camera requirement

Defining and laying out the view controller

Controlling the camera

Subclassing CvVideoCamera

Using the CvVideoCamera subclass in the view controller

Working with various color formats

RGB, BGR, RGBA, and BGRA

YUV and grayscale

Starting and stopping the busy mode

Saving an image to the Photos library

Displaying an alert

Sharing an image via social media

Running the application

Summary

3. Blending Images

Thinking about hybrid images

Planning the blending controls

Expanding the view controller's interface

Expanding the view controller's implementation

Using the application for practical purposes

Seeing changes in a scene

Previewing a new object in a scene

Previewing a copy of a document or drawing

Summary

4. Detecting and Merging Faces of Mammals

Understanding detection with cascade classifiers

Haar-like features

Local binary pattern features

Understanding transformations

Planning a face merging application

Configuring the project

Defining faces and a face detector

Defining and laying out the view controllers

Capturing and previewing real faces

Reviewing, saving, and sharing hybrid faces

Seguing between the view controllers

Detecting a hierarchy of face elements

Aligning and blending face elements

Using the application and acting like a cat

Learning more about face analysis

Summary

5. Classifying Coins and Commodities

Understanding blob detection

Segmentation

Canny edge detection

Contour analysis

Understanding histogram analysis

Understanding keypoint matching

SURF and FLANN

ORB and brute-force Hamming-distance matching

Planning an object classification application

Configuring the project

Defining blobs and a blob detector

Defining blob descriptors and a blob classifier

Laying out the splash screen

Defining and laying out the view controllers

Capturing and previewing blobs

Reviewing, saving, and sharing classified blobs

Seguing between the view controllers

Detecting blobs against a plain background

Classifying blobs by color and keypoints

Using the application and testing the tough cases

An unevenly-lit background

Motion blur

Out of focus

Reflection

Overlapping blobs

Taking your study of OpenCV to the next level

Summary

Index

iOS Application Development with OpenCV 3

Copyright © 2016 Packt Publishing

All rights reserved. No part of this book may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, without the prior written permission of the publisher, except in the case of brief quotations embedded in critical articles or reviews.

Every effort has been made in the preparation of this book to ensure the accuracy of the information presented. However, the information contained in this book is sold without warranty, either express or implied. Neither the author, nor Packt Publishing, and its dealers and distributors will be held liable for any damages caused or alleged to be caused directly or indirectly by this book.

Packt Publishing has endeavored to provide trademark information about all of the companies and products mentioned in this book by the appropriate use of capitals. However, Packt Publishing cannot guarantee the accuracy of this information.

First published: June 2016

Production reference: 1230616

Published by Packt Publishing Ltd.

Livery Place

35 Livery Street

Birmingham B3 2PB, UK.

ISBN 978-1-78528-949-1

www.packtpub.com

Credits

Author

Joseph Howse

Reviewer

Mohit Athwani

Commissioning Editor

Sarah Crofton

Acquisition Editor

Rahul Nair

Content Development Editor

Samantha Gonsalves

Technical Editor

Vivek Arora

Copy Editor

Tasneem Fatehi

Project Coordinator

Sanchita Mandal

Proofreader

Safis Editing

Indexer

Mariammal Chettiyar

Graphics

Disha Haria

Production Coordinator

Arvindkumar Gupta

Cover Work

Arvindkumar Gupta

About the Author

Joseph Howse lives in Canada. During the cold winters, he grows a beard and his four cats grow thick coats of fur. He combs the cats every day. Sometimes the cats pull his beard.

Joseph has been writing for Packt Publishing since 2012. His books include OpenCV for Secret Agents, OpenCV 3 Blueprints, Android Application Programming with OpenCV 3, iOS Application Development with OpenCV 3, Learning OpenCV 3 Computer Vision with Python, and Python Game Programming by Example.

When he is not writing books or grooming cats, Joseph provides consulting, training, and software development services through his company, Nummist Media (http://nummist.com/).

Acknowledgments

As always, Mom, Dad, and the cats have provided all kinds of support, including assistance with the photography in this book.

I am glad for this chance to recognize the iOS developers who trained me years ago. They include Alex Brodsky, Bill Wilson, Jesse Rusak, and Woody Lidstone.

During the writing of this book, I have benefitted from the opportunity to do other OpenCV projects with local colleagues such as Jeff Leadbetter, Matt Wright, Jad Tawil, and Kevin J. Gallant. I am proud that we are part of a growing computer vision community in Atlantic Canada.

Once again, the team at Packt Publishing has supported me with tremendous energy, skill, and loyalty. Thank you! Harsha Bharwani persuaded me to write another OpenCV book. After all, the set was incomplete without iOS. Samantha Gonsalves guided the project to completion, and she never let any complication discourage her or me. All the editors and the technical reviewer have added their marks of quality to the book, and...

Table of contents

• iOS Application Development with OpenCV 3