Book Image

Raspberry Pi By Example

By : Arush Kakkar
Book Image

Raspberry Pi By Example

By: Arush Kakkar

Overview of this book

Want to put your Raspberry Pi through its paces right out of the box? This tutorial guide is designed to get you learning all the tricks of the Raspberry Pi through building complete, hands-on hardware projects. Speed through the basics and then dive right in to development! Discover that you can do almost anything with your Raspberry Pi with a taste of almost everything. Get started with Pi Gaming as you learn how to set up Minecraft, and then program your own game with the help of Pygame. Turn the Pi into your own home security system with complete guidance on setting up a webcam spy camera and OpenCV computer vision for image recognition capabilities. Get to grips with GPIO programming to make a Pi-based glowing LED system, build a complete functioning motion tracker, and more. Finally, get ready to tackle projects that push your Pi to its limits. Construct a complete Internet of Things home automation system with the Raspberry Pi to control your house via Twitter; turn your Pi into a super-computer through linking multiple boards into a cluster and then add in advanced network capabilities for super speedy processing!
Table of Contents (22 chapters)
Raspberry Pi By Example
Credits
About the Authors
About the Reviewers
www.PacktPub.com
Preface
Index

Working with images


Let's get started with the basics of OpenCV's Python API. All the scripts we will write and run will use the OpenCV library, which must be imported with the import cv2 line. We will import few more libraries as required, and in the next sections and chapters, cv2.imread() will be used to import an image. It takes two arguments. The first argument is the image filename. The image should be in the same directory where the Python script is the absolute path that should be provided to cv2.imread(). It reads images and saves them as NumPy arrays.

The second argument is a flag that specifies that the mode image should be read. The flag can have the following values:

  • cv2.IMREAD_COLOR: This loads a color image; it is the default flag

  • cv2.IMREAD_GRAYSCALE: This loads an image in the grayscale mode

  • cv2.IMREAD_UNCHANGED: This loads an image as it includes an alpha channel

The numeric values of the preceding flags are 1, 0, and -1, respectively.

Take a look at the following code:

import...