Book Image

Hands-On Image Processing with Python

By : Sandipan Dey
Book Image

Hands-On Image Processing with Python

By: Sandipan Dey

Overview of this book

Image processing plays an important role in our daily lives with various applications such as in social media (face detection), medical imaging (X-ray, CT-scan), security (fingerprint recognition) to robotics & space. This book will touch the core of image processing, from concepts to code using Python. The book will start from the classical image processing techniques and explore the evolution of image processing algorithms up to the recent advances in image processing or computer vision with deep learning. We will learn how to use image processing libraries such as PIL, scikit-mage, and scipy ndimage in Python. This book will enable us to write code snippets in Python 3 and quickly implement complex image processing algorithms such as image enhancement, filtering, segmentation, object detection, and classification. We will be able to use machine learning models using the scikit-learn library and later explore deep CNN, such as VGG-19 with Keras, and we will also use an end-to-end deep learning model called YOLO for object detection. We will also cover a few advanced problems, such as image inpainting, gradient blending, variational denoising, seam carving, quilting, and morphing. By the end of this book, we will have learned to implement various algorithms for efficient image processing.
Table of Contents (20 chapters)
Title Page
Copyright and Credits
Dedication
About Packt
Contributors
Preface
Index

Harris Corner Detector


This algorithm explores the intensity changes within a window as the window changes location inside an image. Unlike an edge, for which intensity values change abruptly in only one direction, there is a significant change in intensity values at a corner in all directions. Hence, a large change in intensity value should result when the window is shifted in any direction at the corner (with good localization); this fact is exploited in the Harris Corner Detector algorithm. It is invariant to rotation, but not to scale (that is, the corner points found from an image remain unchanged when the image undergoes a rotation transformation, but change when the image is resized). In this section, we shall discuss how to implement a Harris Corner Detector with scikit-image.

With scikit-image

The next code snippet shows how to detect corner points in an image using the Harris Corner Detector with the corner_harris() function from the scikit-imagefeature module:

image = imread('.....