Book Image

OpenNI Cookbook

By : Soroush Falahati
Book Image

OpenNI Cookbook

By: Soroush Falahati

Overview of this book

The release of Microsoft Kinect, then PrimeSense Sensor, and Asus Xtion opened new doors for developers to interact with users, re-design their application’s UI, and make them environment (context) aware. For this purpose, developers need a good framework which provides a complete application programming interface (API), and OpenNI is the first choice in this field. This book introduces the new version of OpenNI. "OpenNI Cookbook" will show you how to start developing a Natural Interaction UI for your applications or games with high level APIs and at the same time access RAW data from different sensors of different hardware supported by OpenNI using low level APIs. It also deals with expanding OpenNI by writing new modules and expanding applications using different OpenNI compatible middleware, including NITE. "OpenNI Cookbook" favors practical examples over plain theory, giving you a more hands-on experience to help you learn. OpenNI Cookbook starts with information about installing devices and retrieving RAW data from them, and then shows how to use this data in applications. You will learn how to access a device or how to read data from it and show them using OpenGL, or use middleware (especially NITE) to track and recognize users, hands, and guess the skeleton of a person in front of a device, all through examples.You also learn about more advanced aspects such as how to write a simple module or middleware for OpenNI itself. "OpenNI Cookbook" shows you how to start and experiment with both NIUI designs and OpenNI itself using examples.
Table of Contents (14 chapters)
OpenNI Cookbook
About the Author
About the Reviewers

Converting the depth unit to millimetre

Until now, we have used the data of the depth stream relatively without knowing its real-world units; in this recipe, however, we are going to show you how it is possible to convert depth data into millimetre units. This could be used for generating point cloud, calculating distance, and so on.

First we try to find the depth value of the center pixel in the depth frame and then use the openni::CoordinateConverter class to convert this value into a real-world millimetre unit.

Getting ready

Create a project in Visual Studio 2010 and prepare it for working with OpenNI using the Creating a project in Visual Studio 2010 recipe of Chapter 2, OpenNI and C++.

How to do it...

  1. Add the following lines at the top of your source code (just below the #include lines):

    #include <conio.h>
  2. Copy the ReadLastCharOfLine() and HandleStatus() functions here from the last recipe.

  3. Then locate the following lines of code:

    int _tmain(int argc, _TCHAR* argv[])
  4. Write the following...