Book Image

Building Computer Vision Projects with OpenCV 4 and C++

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

Building Computer Vision Projects with OpenCV 4 and C++

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

Overview of this book

OpenCV is one of the best open source libraries available and can help you focus on constructing complete projects on image processing, motion detection, and image segmentation. This Learning Path is your guide to understanding OpenCV concepts and algorithms through real-world examples and activities. Through various projects, you'll also discover how to use complex computer vision and machine learning algorithms and face detection to extract the maximum amount of information from images and videos. In later chapters, you'll learn to enhance your videos and images with optical flow analysis and background subtraction. Sections in the Learning Path will help you get to grips with text segmentation and recognition, in addition to guiding you through the basics of the new and improved deep learning modules. By the end of this Learning Path, you will have mastered commonly used computer vision techniques to build OpenCV projects from scratch. This Learning Path includes content from the following Packt books: •Mastering OpenCV 4 - Third Edition by Roy Shilkrot and David Millán Escrivá •Learn OpenCV 4 By Building Projects - Second Edition by David Millán Escrivá, Vinícius G. Mendonça, and Prateek Joshi
Table of Contents (28 chapters)
Title Page
Copyright and Credits
About Packt
Contributors
Preface
Index

Creating a library


CMake allows us to create libraries used by the OpenCV build system. Factorizing shared code among multiple applications is a common and useful practice in software development. In big applications, or common code shared in multiple applications, this practice is very useful. In this case, we do not create a binary executable, but instead we create a compiled file that includes all the functions, classes, and so on. We can then share this library file with other applications without sharing our source code.

CMake includes the add_library function to this end:

# Create our hello library 
    add_library(Hello hello.cpp hello.h) 
 
# Create our application that uses our new library 
    add_executable(executable main.cpp) 
 
# Link our executable with the new library 
    target_link_libraries(executable Hello) 

The lines starting with # add comments and are ignored by CMake. The add_library (Hello hello.cpp hello.h) command defines the source files of our library and its name...