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

Creating the Graphical User Interface


Before we start with the image processing algorithms, we will create the main user interface for our application. We will use a QT-based user interface to allow us to create single buttons.

The application receives one input parameter to load the image to be processed, and we will create the following four buttons:

  • Show histogram

  • Equalize histogram

  • Lomography effect

  • Cartoonize effect

We can see the four results in the following screenshot:

Let's develop our project. First of all, we will include the required OpenCV headers. We define an img matrix to store the input image, and create a constant string to use the new command-line parser, which is only available in OpenCV 3.0. In this constant, we allow only two input parameters: common help and the required image input:

// OpenCV includes
#include "opencv2/core/utility.hpp"
#include "opencv2/imgproc.hpp"
#include "opencv2/highgui.hpp"
using namespace cv;
// OpenCV command line parser functions
// Keys...