Visual Media Processing Using Matlab Beginner's Guide电子书

Visual Media Processing Using MATLAB Beginner's Guide

Table of Contents

Visual Media Processing Using MATLAB Beginner's Guide

Credits

About the Author

About the Reviewers

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Free Access for Packt account holders

Preface

What this book covers

What you need for this book

Who this book is for

Conventions

Time for action – heading

What just happened?

Pop quiz – heading

Have a go hero – heading

Reader feedback

Customer support

Downloading the example code

Errata

Piracy

Questions

1. Basic Image Manipulations

Getting acquainted with the MATLAB environment

Default subwindows of the environment

The Command Window

The Current Folder window

The Details window

The Workspace window

The ribbon

The HOME tab

The PLOTS tab

The APPS tab

The editor

The EDITOR window

Importing and displaying an image

Importing and displaying an image using the command line

Time for action – importing and displaying an image

What just happened?

Importing and displaying an image using imtool

Time for action – using imtool to extract useful information

What just happened?

Applying geometric transformations

Performing image rotation

Time for action – rotating an image and displaying the result

What just happened?

Performing image mirroring

Time for action – mirroring an image and displaying the result

What just happened?

Have a go hero – using flipdim and comparing the results

Resizing an image

Cropping an image

Saving an image

Time for action – cropping and resizing an image, then saving it as BMP

What just happened?

Have a go hero – tailoring an image to suit your needs

Pop quiz – image processing in MATLAB

Summary

2. Working with Pixels In Grayscale Images

Accessing image pixels and changing their values

Changing the pixel values of a square area using loops

Changing the pixel values of a square area using indexing

Writing and using scripts

Time for action – whiten an area and blacken another

What just happened?

Thresholding an image

Image thresholding using for loops

Image thresholding using indexing

Image thresholding using im2bw

Image thresholding using an automatic threshold

Calculating and displaying histograms with imhist

Histogram equalization for contrast enhancement

Contrasting enhancement using imadjust

Contrasting enhancement using imcontrast

Adaptive histogram equalization using adapthisteq

Custom functions for complex tasks

Time for action – using imtool to pinpoint differences

What just happened?

Have a go hero – writing a function to enhance an image area

Restoring old photographs

Time for action – restoring your ancestors' photographs

What just happened?

Pop quiz – contrasting enhancement methods

Summary

3. Morphological Operations and Object Analysis

The importance of binary images

Time for action – understanding the value of thresholding

What just happened?

Enlarging and shrinking a region of interest

Time for action – using dilation and erosion to refine ROIs

What just happened?

Choosing a structuring element

Using strel to generate structuring elements

Altering structuring elements from strel to suit our needs

Time for action – ROI refinement using strel

What just happened?

Have a go hero – write a function to for local dilation/erosion

More morphological operations

Manually defining a non-rectangular ROI

Using roipoly to make a mask

Using imfreehand to make a mask

Time for action – making a custom object eraser function

What just happened?

Analyzing objects in an image

Detecting edges in an image

Detecting corners in an image

Detecting circles in an image

Pop quiz – object analysis pros and cons

Summary

4. Working with Color Images

An introduction to color image processing

Basic color image manipulations

Setting a rectangular area to a specified color

Time for action – repainting two areas in a color image

What just happened?

Thresholding color images

Time for action – isolating the red pixels in an image

What just happened?

Achieving color masking

Time for action – color isolation

What just happened?

The importance of different color spaces

Time for action – color space transformation

What just happened?

CIE-L*a*b* for more efficient color masking

Time for action – color isolation using CIE-L*a*b*

What just happened?

Have a go hero – writing a function for region color isolation

Fixing illumination issues in RGB color images

Fixing illumination issues in CIE-L*a*b*

A practical example – red eye reduction

Time for action – writing a function for red eye reduction

What just happened?

Taking advantage of eye circularity

Time for action – automating our function for red eye reduction

What just happened?

Pop quiz – working with color

Summary

5. 2-Dimensional Image Filtering

An introduction to image filtering

Processing neighborhoods of pixels

The basics of convolution

The ugly mathematical truth

Time for action – applying averaging filters in images

What just happened?

Alternatives to convolution

Using imfilter

Creating filters with fspecial

Different ways to blur an image

Time for action – how much blurring is enough

What just happened?

Time to make art using blurring

Time for action – creating the bokeh effect in an image

What just happened?

Have a go hero – add a motion effect in your image

Removing noise using blurring

Time for action – trying to remove different types of noise

What just happened?

The importance of the median filter

Time for action – removing salt & pepper with medfilt2

What just happened?

Have a go hero – denoising real images

Bringing back the details

Time for action – enhancing the edges in our images

What just happened?

Brighten up the lights

Time for action – brighten up the lights in our soldier picture

Pop quiz – image filtering in 2-dimensions

Summary

6. Mixing Images for Science or Art

The importance of mixing or combining images

Using multispectral imaging

Loading and manipulating the multispectral images

Time for action – visible spectrum from a multiband image of Rio

What just happened?

Time for action – working with invisible spectrums

What just happened?

Creating composite images

Using imfuse to create a composite image

Using imshowpair to inspect a composite image

Time for action – cloning the seagull

What just happened?

Have a go hero – playing Warhol with your pictures

One step beyond – blending selected image regions

Time for action – directing a threatening scene

What just happened?

Creating High Dynamic Range images

Time for action – composing your own HDR images

What just happened?

Stitching images for the creation of panoramas

Time for action – basic approach to panorama stitching

What just happened?

Pop quiz – image mixing details

Summary

7. Adding Motion – From Static Images to Digital Videos

An introduction to digital videos

The meaning of frames

Interlaced versus progressive

Frame rates and their importance

Calculating number of frames

Some thoughts on choosing frame rates

Loading videos in MATLAB

Loading videos with aviread

Loading videos with mmreader

Loading videos with VideoReader

Choosing which function to use for video reading

Playing back videos in MATLAB

Time for action – reading and playing back a video

What just happened?

Making videos from static images

Time for action – constructing and saving a video

What just happened?

Have a go hero – make a video with a fade in/fade out effect

Inspecting a video using montage

Time for action – don't wait for the ball

What just happened?

A tool just for your playback needs – implay

Using the GUI of implay

Using implay to play a video file

Using implay to play an image sequence

Creating time-lapse videos

Time for action – time-lapsing a regular video

What just happened?

Have a go hero – spinning our time-lapse

Saving your time-lapse videos in a gif file

Pop quiz – image filtering in 2-dimensions

Summary

8. Acquiring and Processing Videos

Using MATLAB for digital video recording

The Hardware Browser window

The Information window

The Desktop Help window

The Preview window

The Acquisition Parameters window

The General tab

The Device Properties tab

The Logging tab

The Triggering tab

The Region of Interest tab

The Session Log window

Time for action – capturing a video using a firewire connection

What just happened?

Have a go hero – adding a trigger to our recording

The importance of video compression

Checking the size of an uncompressed video

Checking the size of an MP4 video without any motion

Checking the size of an MP4 video with high motion

Working with uncompressed videos

Working with large videos in postproduction

Time for action – making an edge detection video

What just happened?

Have a go hero – getting the last chunk of frames processed

Pop quiz – what is the problem with our function?

Acquiring frames for time-lapse videos

Detecting your acquisition hardware

Creating a video object and acquiring a frame

Time for action – using MATLAB as an intervalometer

What just happened?

Have a go hero – creating a time-lapse creation function

Real-time processing of time-lapse videos

Time for action – creating time-lapses with isolated colors

What just happened?

Real-time processing of normal videos

Evaluating real-time capabilities with a simple example

Time for action – adjusting the contrast of the video

What just happened?

Revisiting the contrast adjustment example

Time for action – adding preview in our code

What just happened?

Have a go hero – doubling the speed of our code

Pop quiz – acquiring and processing videos

Summary

9. Spatiotemporal Video Processing

Basic video processing with MATLAB

Cropping and resizing our video

Time for action – loading, cropping, resizing, and saving a video

What just happened?

Have a go hero – adding rotation and more error-checking

Filtering your video frames

Time for action – reducing the blocking effect

What just happened?

Deinterlacing videos in MATLAB

Intra-frame filtering for deinterlacing tasks

Deinterlacing with the Computer Vision System Toolbox

Time for action – deinterlacing a video using the vision toolbox

What just happened?

Have a go hero – comparing the deinterlacing methods

Deinterlacing with the custom functions

Time for action – deinterlacing with line repetition

What just happened?

Time for action – deinterlacing with the scan line interpolation

What just happened?

Have a go hero – comparing the deinterlacing methods

Inter-frame filtering for the deinterlacing tasks

Temporal deinterlacing by field merging

Time for action – deinterlacing with field merging

What just happened?

Have a go hero – evaluating the field merge method

Temporal deinterlacing by field averaging

Time for action – deinterlacing with field averaging

What just happened?

Mixing intra-frame and inter-frame deinterlacing

Vertical and temporal interpolation for deinterlacing

Time for action – vertical and temporal interpolation method

What just happened?

Have a go hero – Comparing deinterlacing techniques

Adding a new dimension to the filters

Spatiotemporal averaging filter

Time for action – implementing a spatiotemporal averaging filter

What just happened?

Have a go hero – creating a spatiotemporal median filter

Using convolution for spatiotemporal averaging

Time for action – spatiotemporal averaging filter with the convn function

What just happened?

Pop quiz – videos and filters

Summary

10. From Beginner to Expert – Handling Motion and 3-D

Detecting and estimating motion in videos

Detecting motion

Time for action – detecting a moving object in a still scene

What just happened?

Time for action – detecting motion in a complex scene

What just happened?

Have a go hero – making your own surveillance system

Estimating the motion

Estimating motion using optical flow

Time for action – tracking people with Horn-Schunck optical flow

What just happened?

Have a go hero – estimating optical flow using Lucas-Kanade

Time for action – warping frames using optical flow

What just happened?

Have a go hero – making your own surveillance system

Compensating camera motion using feature tracking

Time for action – tracking feature points for motion compensation of a shaky video

What just happened?

Have a go hero – tweaking the settings of the stabilization demo

Working with stereoscopic images

Time for action – creating a 3-D video from left and right videos

What just happened?

Time for action – creating a 3-D video from a regular one

What just happened?

Have a go hero – writing a function for 3-D video creation

Pop quiz –working with video frames

Summary

A. Pop Quiz Answers

Chapter 1, Basic Image Manupulation

Pop quiz – image processing in Matlab

Chapter 2, Working with Pixels in Grayscale Images

Pop quiz – contrasting enhancement methods

Chapter 3, Morphological Operations and Object Analysis

Pop quiz – object analysis pros and cons

Chapter 4, Working with Color Images

Pop quiz – working with color

Chapter 5, 2-Dimensional Image Filtering

Pop quiz – image filtering in 2-dimensions

Chapter 6, Mixing Images for Science or Art

Pop quiz – image mixing details

Chapter 7, Adding Motion – From Static Images to Digital Videos

Pop quiz – image filtering in 2-dimensions

Chapter 8, Acquiring and Processing Videos

Pop quiz – what is the problem with our function?

Pop quiz – acquiring and processing videos

Chapter 9, Spatiotemporal Video Processing

Pop quiz – videos and filters

Chapter 10, From Beginner to Expert – Handling Motion and 3-D

Pop quiz – working with video frames

Index