Chapter 1, Setting Up Software and Hardware, covers the installation of an iOS development environment and OpenCV. To test our setup, we build a minimal application, CoolPig, which manipulates colors in a picture of a pig. Finally, we consider some photographic techniques and accessories.

Chapter 2, Capturing, Storing, and Sharing Photos, deals with camera control, the Photos library, and social networks. We build a photography app, LightWork.

Chapter 3, Blending Images, adds new features to our LightWork app. We use simple arithmetic operations as well as more complex filters to blend pairs of images in real time.

Chapter 4, Detecting and Merging Faces of Mammals, is about detection, classification, and geometric transformation, with an emphasis on faces. We create an application called ManyMasks, which can align and blend the faces of humans, cats, and possibly other mammals.

Chapter 5, Classifying Coins and Commodities, deals with detection and classification but with an emphasis on objects that have distinctive colors or designs. Our final application, BeanCounter, can classify coins, beans, and other objects, depending on a configuration file and a set of training images.

You need a computer running Mac OS 10.10 (or a later version) as well as an iPhone, iPad, or iPod Touch running iOS 9 (or a later version).

On your computer, you need to install Apple's standard tools for iOS developers. These include Xcode, iOS SDK, and the Xcode Command Line Tools. You also need to set up OpenCV 3.1 (or a later version). All this software is free, and Chapter 1, Setting Up Software and Hardware, provides setup instructions.

This book is great for developers who are new to iOS, computer vision, or both. Previous experience with Objective-C or C++ is recommended.

In this book, you will find a number of text styles that distinguish between different kinds of information. Here are some examples of these styles and an explanation of their meaning.

Code words in text, database table names, folder names, filenames, file extensions, pathnames, dummy URLs, user input, and Twitter handles are shown as follows: "Next, let's define the instance variables of the ViewController class."

A block of code is set as follows:

- (void)startBusyMode {
  dispatch_async(dispatch_get_main_queue(), ^{
    [self.activityIndicatorView startAnimating];
    for (UIBarItem *item in self.toolbar.items) {
      item.enabled = NO;
    }
  });
}

Any command-line input or output is written as follows:

$ ./<opencv_source_path>/platforms/ios/build_framework.py <opencv_contrib_build_path> --contrib <opencv_contrib_source_path>

New terms and important words are shown in bold. Words that you see on the screen, for example, in menus or dialog boxes, appear in the text like this: "Choose the Value Changed event, which occurs when the user selects a new option in the segmented control."

Feedback from our readers is always welcome. Let us know what you think about this book—what you liked or disliked. Reader feedback is important for us as it helps us develop titles that you will really get the most out of.

To send us general feedback, simply e-mail <[email protected]>, and mention the book's title in the subject of your message.

If there is a topic that you have expertise in and you are interested in either writing or contributing to a book, see our author guide at www.packtpub.com/authors.

Now that you are the proud owner of a Packt book, we have a number of things to help you to get the most from your purchase.