Book Image

Qt 5 and OpenCV 4 Computer Vision Projects

By : Zhuo Qingliang
4 (1)
Book Image

Qt 5 and OpenCV 4 Computer Vision Projects

4 (1)
By: Zhuo Qingliang

Overview of this book

OpenCV and Qt have proven to be a winning combination for developing cross-platform computer vision applications. By leveraging their power, you can create robust applications with both an intuitive graphical user interface (GUI) and high-performance capabilities. This book will help you learn through a variety of real-world projects on image processing, face and text recognition, object detection, and high-performance computing. You’ll be able to progressively build on your skills by working on projects of increasing complexity. You’ll begin by creating an image viewer application, building a user interface from scratch by adding menus, performing actions based on key-presses, and applying other functions. As you progress, the book will guide you through using OpenCV image processing and modification functions to edit an image with filters and transformation features. In addition to this, you’ll explore the complex motion analysis and facial landmark detection algorithms, which you can use to build security and face detection applications. Finally, you’ll learn to use pretrained deep learning models in OpenCV and GPUs to filter images quickly. By the end of this book, you will have learned how to effectively develop full-fledged computer vision applications with OpenCV and Qt.
Table of Contents (11 chapters)

Building an Image Viewer

Computer vision is the technology that enables computers to achieve a high-level understanding of digital images and videos, rather than only treating them as bytes or pixels. It is widely used for scene reconstruction, event detection, video tracking, object recognition, 3D pose estimation, motion estimation, and image restoration.

OpenCV (open source computer vision) is a library that implements almost all computer vision methods and algorithms. Qt is a cross-platform application framework and widget toolkit for creating applications with graphical user interfaces that can run on all major desktop platforms, most embedded platforms, and even mobile platforms.

These two powerful libraries are used together by many developers to create professional software with a solid GUI in industries that benefit from computer vision technology. In this book, we will demonstrate how to build these types of functional application with Qt 5 and OpenCV 4, which has friendly graphical user interfaces and several functions associated with computer vision technology.

In this first chapter, we will start by building a simple GUI application for image viewing with Qt 5.

The following topics will be covered in this chapter as follows:

  • Designing the user interface
  • Reading and displaying images with Qt
  • Zooming in and out of images
  • Saving a copy of images in any supported format
  • Responding to hotkeys in a Qt application