Book Image

OpenCV By Example

By : Prateek Joshi, David Millán Escrivá, Vinícius G. Mendonça
Book Image

OpenCV By Example

By: Prateek Joshi, David Millán Escrivá, Vinícius G. Mendonça

Overview of this book

Open CV is a cross-platform, free-for-use library that is primarily used for real-time Computer Vision and image processing. It is considered to be one of the best open source libraries that helps developers focus on constructing complete projects on image processing, motion detection, and image segmentation. Whether you are completely new to the concept of Computer Vision or have a basic understanding of it, this book will be your guide to understanding the basic OpenCV concepts and algorithms through amazing real-world examples and projects. Starting from the installation of OpenCV on your system and understanding the basics of image processing, we swiftly move on to creating optical flow video analysis or text recognition in complex scenes, and will take you through the commonly used Computer Vision techniques to build your own Open CV projects from scratch. By the end of this book, you will be familiar with the basics of Open CV such as matrix operations, filters, and histograms, as well as more advanced concepts such as segmentation, machine learning, complex video analysis, and text recognition.
Table of Contents (18 chapters)
OpenCV By Example
Credits
About the Authors
About the Reviewers
www.PacktPub.com
Preface
Index

OpenGL support


OpenCV includes OpenGL support. OpenGL is a graphical library that is integrated in graphic cards as a standard. OpenGL allow us to draw from 2D to complex 3D scenes.

OpenCV includes OpenGL support due to the importance of representing 3D spaces in some tasks. To allow a window support in OpenGL, we have to set up the WINDOW_OPENGL flag when we create the window with the namedWindow call.

The following code creates a window with OpenGL support and draws a rotated plane that shows the web camera frames:

Mat frame;
GLfloat angle= 0.0;
GLuint texture; 
VideoCapture camera;

int loadTexture() {

    if (frame.data==NULL) return -1;
glGenTextures(1, &texture);
   glBindTexture( GL_TEXTURE_2D, texture ); 
   glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MAG_FILTER,GL_LINEAR);
   glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MIN_FILTER,GL_LINEAR);
   glPixelStorei(GL_UNPACK_ALIGNMENT, 1);

   glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, frame.cols, frame.rows,0, GL_BGR, GL_UNSIGNED_BYTE, frame...