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

Reading users' bounding boxes and center of mass

In this recipe, we are going to expand on the preceding recipe by showing the bounding box and the center of visual mass (COM) of a user. The bounding box of a user shows the size and location of a user in screen and, for any user, the center of the visual mass is the center of distribution of the pixels.

More precisely, its x position is equal to the average of all the users' pixels x position, and its y position is equal to the average of all the users' pixels y position.

Almost the same is true about its z position, which is equal to the average of all the depth values of users' pixels.

Getting ready

Create a project in Visual Studio and prepare it for working with OpenNI and NiTE using the Create a project in Visual Studio 2010 recipe in Chapter 2, OpenNI and C++, and then configure Visual Studio to use OpenGL using the Configuring Visual Studio 2010 to use OpenGL recipe in the previous chapter.

Then copy the code from the Identifying and coloring...