Book Image

Learning OpenCV 4 Computer Vision with Python 3 - Third Edition

By : Joseph Howse, Joe Minichino
Book Image

Learning OpenCV 4 Computer Vision with Python 3 - Third Edition

By: Joseph Howse, Joe Minichino

Overview of this book

Computer vision is a rapidly evolving science, encompassing diverse applications and techniques. This book will not only help those who are getting started with computer vision but also experts in the domain. You’ll be able to put theory into practice by building apps with OpenCV 4 and Python 3. You’ll start by understanding OpenCV 4 and how to set it up with Python 3 on various platforms. Next, you’ll learn how to perform basic operations such as reading, writing, manipulating, and displaying still images, videos, and camera feeds. From taking you through image processing, video analysis, and depth estimation and segmentation, to helping you gain practice by building a GUI app, this book ensures you’ll have opportunities for hands-on activities. Next, you’ll tackle two popular challenges: face detection and face recognition. You’ll also learn about object classification and machine learning concepts, which will enable you to create and use object detectors and classifiers, and even track objects in movies or video camera feed. Later, you’ll develop your skills in 3D tracking and augmented reality. Finally, you’ll cover ANNs and DNNs, learning how to develop apps for recognizing handwritten digits and classifying a person's gender and age. By the end of this book, you’ll have the skills you need to execute real-world computer vision projects.
Table of Contents (13 chapters)

Creating modules

Let's revisit the Cameo project that we started in Chapter 2, Handling Files, Cameras, and GUIs. We can modify Cameo so that it applies filters to the captured images in real time. As in the case of our CaptureManager and WindowManager classes, our filters should be reusable outside of Cameo. Thus, we should separate the filters into their own Python module or file.

Let's create a file called filters.py in the same directory as cameo.py. We need the following import statements in filters.py:

import cv2
import numpy
import utils

Let's also create a file called utils.py in the same directory. It should contain the following import statements:

import cv2
import numpy
import scipy.interpolate

We will be adding filter functions and classes to filters.py, while more general-purpose math functions will go in utils.py.

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