4. Controlling a Phone App with Your Suave Gestures | OpenCV for Secret Agents

Sign In Start Free Trial

Book Overview & Buying
Table Of Contents

OpenCV for Secret Agents

By : Joseph Howse

5 (5)

OpenCV for Secret Agents

5 (5)

By: Joseph Howse

Overview of this book

This book is for programmers who want to expand their skills by building fun, smart, and useful systems with OpenCV. The projects are ideal in helping you to think creatively about the uses of computer vision, natural user interfaces, and ubiquitous computers (in your home, car, and hand).

Preface

Preface

What this book covers

What you need for this book

Who this book is for

Conventions

Reader feedback

Customer support

Free Chapter

1. Preparing for the Mission

1. Preparing for the Mission

Setting up a development machine

Setting up Raspberry Pi

Finding OpenCV documentation, help, and updates

Alternatives to Raspberry Pi

Summary

2. Searching for Luxury Accommodations Worldwide

2. Searching for Luxury Accommodations Worldwide

Planning the Luxocator app

Creating, comparing, and storing histograms

Training the classifier with reference images

Acquiring images from the Web

Acquiring images from Bing image search

Preparing images and resources for the app

Integrating everything into the GUI

Building Luxocator for distribution

Summary

3. Training a Smart Alarm to Recognize the Villain and His Cat

3. Training a Smart Alarm to Recognize the Villain and His Cat

Understanding machine learning in general

Planning the Interactive Recognizer app

Understanding Haar cascades and LBPH

Implementing the Interactive Recognizer app

Planning the cat detection model

Implementing the training script for the cat detection model

Planning the Angora Blue app

Implementing the Angora Blue app

Building Angora Blue for distribution

Further fun with finding felines

Summary

4. Controlling a Phone App with Your Suave Gestures

4. Controlling a Phone App with Your Suave Gestures

Planning the Goldgesture app

Understanding optical flow

Setting up the Eclipse Workspace

Getting a cascade file and audio files

Specifying the app's requirements

Laying out a camera preview as the main view

Tracking back and forth gestures

Playing audio clips as questions and answers

Capturing images and tracking faces in an activity

Summary

5. Equipping Your Car with a Rearview Camera and Hazard Detection

5. Equipping Your Car with a Rearview Camera and Hazard Detection

Planning The Living Headlights app

Detecting lights as blobs

Estimating distances (a cheap approach)

Implementing The Living Headlights app

Testing The Living Headlights app at home

Testing The Living Headlights app in a car

Summary

6. Seeing a Heartbeat with a Motion Amplifying Camera

6. Seeing a Heartbeat with a Motion Amplifying Camera

Planning the Lazy Eyes app

Understanding what Eulerian video magnification can do

Extracting repeating signals from video using the Fast Fourier Transform (FFT)

Compositing two images using image pyramids

Implementing the Lazy Eyes app

Configuring and testing the app for various motions

Seeing things in another light

Summary

7. Creating a Physics Simulation Based on a Pen and Paper Sketch

7. Creating a Physics Simulation Based on a Pen and Paper Sketch

Planning the Rollingball app

Detecting circles and lines

Setting up OpenCV for Unity

Configuring and building the Unity project

Creating the Rollingball scene in Unity

Creating Unity assets and adding them to the scene

Tidying up and testing

Summary

Index

Index

Tracking back and forth gestures

Several common gestures consist of a repetitive, back and forth movement. Consider the following examples of this type of gesture:

Nodding (yes or I'm listening)
Shaking one's head (no or dismay)
Waving (a greeting)
Shaking hands (a greeting)
Shaking one's fist (a threat or a protest)
Wagging a finger (scolding)
Wiggling a finger or fingers (beckoning)
Tapping one's foot against the ground (impatience)
Tapping four fingers against a table (impatience)
Tapping two fingers against a table ("Thanks for the green tea")
Pacing (anxiety)
Jumping up and down (excitement, joy)

To help us recognize such gestures, let's write a class, BackAndForthGesture, which keeps track of the number of times that a value (such as an x coordinate or a y coordinate) has oscillated between a low threshold and a high threshold. A certain number of oscillations can be considered as a complete gesture.

Create a file, src/BackAndForthGesture.java. As a member variable, BackAndForthGesture will store...

CONTINUE READING

83

Tech Concepts

36

Programming languages

73

Tech Tools

Unlimited access to the largest independent learning library in tech of over 8,000 expert-authored tech books and videos.

Innovative learning tools, including AI book assistants, code context explainers, and text-to-speech.

50+ new titles added per month and exclusive early access to books as they are being written.

OpenCV for Secret Agents

Search

Your notes and bookmarks