Book Image

OpenCV 3 Blueprints

By : Joseph Howse, Puttemans, Sinha
Book Image

OpenCV 3 Blueprints

By: Joseph Howse, Puttemans, Sinha

Overview of this book

Computer vision is becoming accessible to a large audience of software developers who can leverage mature libraries such as OpenCV. However, as they move beyond their first experiments in computer vision, developers may struggle to ensure that their solutions are sufficiently well optimized, well trained, robust, and adaptive in real-world conditions. With sufficient knowledge of OpenCV, these developers will have enough confidence to go about creating projects in the field of computer vision. This book will help you tackle increasingly challenging computer vision problems that you may face in your careers. It makes use of OpenCV 3 to work around some interesting projects. Inside these pages, you will find practical and innovative approaches that are battle-tested in the authors’ industry experience and research. Each chapter covers the theory and practice of multiple complementary approaches so that you will be able to choose wisely in your future projects. You will also gain insights into the architecture and algorithms that underpin OpenCV’s functionality. We begin by taking a critical look at inputs in order to decide which kinds of light, cameras, lenses, and image formats are best suited to a given purpose. We proceed to consider the finer aspects of computational photography as we build an automated camera to assist nature photographers. You will gain a deep understanding of some of the most widely applicable and reliable techniques in object detection, feature selection, tracking, and even biometric recognition. We will also build Android projects in which we explore the complexities of camera motion: first in panoramic image stitching and then in video stabilization. By the end of the book, you will have a much richer understanding of imaging, motion, machine learning, and the architecture of computer vision libraries and applications!
Table of Contents (9 chapters)
8
Index

The Android section – an application user interface


In this section, we will show you a basic user interface to capture and save the panorama to the internal storage. Basically, the user will see a fullscreen of the camera preview image. When the user presses the Capture button, the application will capture the current scene and put the captured image on an overlay layer above the current view. Therefore, the user knows what they have just captured and can change the phone position to capture the next image.

The following is a screenshot of the application when the user opens it and after the user captures an image:

An example of the user interface before and after a user captures an image

The setup activity layout

First, we will create a new Android project with a blank activity in Android Studio. Then, we will edit the layout xml for MainActivity in app/src/main/res/layout/activity_main.xml as follows:

<RelativeLayout   xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns...