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

Slimming the shapes


We can achieve this effect using an operation called erosion. This is an operation that makes a shape thinner by peeling the boundary layers of all the shapes in the image:

Let's take a look at the function that performs morphological erosion:

Mat performErosion(Mat inputImage, int erosionElement, int erosionSize)
{
    Mat outputImage;
    int erosionType;
    
    if(erosionElement == 0)
        erosionType = MORPH_RECT;
    
    else if(erosionElement == 1)
        erosionType = MORPH_CROSS;
    
    else if(erosionElement == 2)
        erosionType = MORPH_ELLIPSE;
    
    // Create the structuring element for erosion
    Mat element = getStructuringElement(erosionType, Size(2*erosionSize + 1, 2*erosionSize + 1), Point(erosionSize, erosionSize));
    
    // Erode the image using the structuring element
    erode(inputImage, outputImage, element);
    
    // Return the output image
    return outputImage;
}

You can check out the complete code in the .cpp files to understand...