Book Image

Visual Media Processing Using MATLAB Beginner's Guide

By : George Siogkas
Book Image

Visual Media Processing Using MATLAB Beginner's Guide

By: George Siogkas

Overview of this book

Whether you want to enhance your holiday photographs or make a professional banner image for your website, you need a software tool that offers you quick and easy ways to accomplish it. All-in-one tools tend to be rare, and Matlab is one of the best available.This book is a practical guide full of step-by-step examples and exercises that will enable you to use Matlab as a powerful, complete, and versatile alternative to traditional image and video processing software.You will start off by learning the very basics of grayscale image manipulation in Matlab to master how to analyze 3-dimensional images and videos using the same tool. The methods you learn here are explained and expanded upon so that you gradually reach a more advanced level in Matlab image and video processing. You will be guided through the steps of opening, transforming, and saving images, later to be mixed with advanced masking techniques both in grayscale and in color. More advanced examples of artistic image processing are also provided, like creating panoramic photographs or HDR images. The second part of the book covers video processing techniques and guides you through the processes of creating time-lapse videos from still images, and acquiring, filtering, and saving videos in Matlab. You will learn how to use many useful functions and tools that transform Matlab from a scientific software to a powerful and complete solution for your everyday image and video processing needs.
Table of Contents (18 chapters)
Visual Media Processing Using MATLAB Beginner's Guide
Credits
About the Author
About the Reviewers
www.PacktPub.com
Preface
Index

The importance of video compression


In our first example in this chapter, we saved an uncompressed AVI video. This led to a very quick appearance of the message informing us of reaching the limit of 500 MB. The number of frames captured until the appearance of the message was 401, which equals to the duration of approximately 13.37 seconds. Quite a large size for such a small video!

Let's do some math to understand how this works. As we recall from the previous chapter, the memory that an uncompressed 8-bit video consumes can be calculated by multiplying its total number of pixels, by the number of frames by three (the number of color channels). The resulting size is counted in bytes.

Checking the size of an uncompressed video

We will now try to verify that our resulting video file is as large as we expected it to be, using Command Window. First we will get the size of our video file:

>> vidInfo = dir('E:\Videos\Acquisition\test.avi'); % get file info 
>> fileSize = vidInfo.bytes...