Book Image

Mastering iOS 12 Programming - Third Edition

By : Donny Wals
Book Image

Mastering iOS 12 Programming - Third Edition

By: Donny Wals

Overview of this book

The iOS development environment has significantly matured, and with Apple users spending more money in the App Store, there are plenty of development opportunities for professional iOS developers. However, the journey to mastering iOS development and the new features of iOS 12 is not straightforward. This book will help you make that transition smoothly and easily. With the help of Swift 4.2, you’ll not only learn how to program for iOS 12, but also how to write efficient, readable, and maintainable Swift code that maintains industry best practices. Mastering iOS 12 Programming will help you build real-world applications and reflect the real-world development flow. You will also find a mix of thorough background information and practical examples, teaching you how to start implementing your newly gained knowledge. By the end of this book, you will have got to grips with building iOS applications that harness advanced techniques and make best use of the latest and greatest features available in iOS 12.
Table of Contents (35 chapters)
Title Page
Copyright and Credits
Dedication
Packt Upsell
Contributors
Preface
Index

Manipulating photos with Core Image


In this chapter, you have already seen that iOS has powerful capabilities for recording and playing media. In this section, you will learn how you can manipulate images with Core Image. The Core Image framework provides many different filters that you can use to process both images and video. You will expand on the photo-taking capabilities that you implemented in the Captured app so users can grayscale and crop images.

Every Core Image filter you apply to images is an instance of the CIFilter class. You can create instances of filters as follows:

let filter = CIFilter(name: "CIPhotoEffectNoir")

The name parameter in the filter's initializer is expected to be a string that refers to a specific filter. You can refer to Apple's documentation on Core Image and the Core Image Filter Reference guide to see an overview of all the filters that you can use in your apps.

Every filter has a certain set of parameters that you need to set on the CIFilter instance to use...