OpenCV Computer Vision Application programming Cookbook Second Edition电子书

OpenCV Computer Vision Application Programming Cookbook Second Edition

Table of Contents

OpenCV Computer Vision Application Programming Cookbook Second Edition

Credits

About the Author

About the Reviewers

www.PacktPub.com

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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

Reader feedback

Customer support

Downloading the example code

Errata

Piracy

Questions

1. Playing with Images

Introduction

Installing the OpenCV library

Getting ready

How to do it...

How it works...

There's more...

Using Qt for OpenCV developments

The OpenCV developer site

See also

Loading, displaying, and saving images

Getting ready

How to do it...

How it works...

There's more...

Clicking on images

Drawing on images

Running the example with Qt

See also

Exploring the cv::Mat data structure

How to do it...

How it works...

There's more...

The input and output arrays

The old IplImage structure

See also

Defining regions of interest

Getting ready

How to do it...

How it works...

There's more...

Using image masks

See also

2. Manipulating Pixels

Introduction

Accessing pixel values

Getting ready

How to do it...

How it works...

There's more...

The cv::Mat_ template class

See also

Scanning an image with pointers

Getting ready

How to do it...

How it works...

There's more...

Other color reduction formulas

Having input and output arguments

Efficient scanning of continuous images

Low-level pointer arithmetics

See also

Scanning an image with iterators

Getting ready

How to do it...

How it works...

There's more...

See also

Writing efficient image-scanning loops

How to do it...

How it works...

There's more…

See also

Scanning an image with neighbor access

Getting ready

How to do it...

How it works...

There's more...

See also

Performing simple image arithmetic

Getting ready

How to do it...

How it works...

There's more...

Overloaded image operators

Splitting the image channels

Remapping an image

How to do it...

How it works...

See also

3. Processing Color Images with Classes

Introduction

Using the Strategy pattern in an algorithm design

Getting ready

How to do it…

How it works…

There's more…

Computing the distance between two color vectors

Using OpenCV functions

The functor or function object

See also

Using a Controller design pattern to communicate with processing modules

Getting ready

How to do it…

How it works…

There's more…

The Model-View-Controller architecture

Converting color representations

Getting ready

How to do it…

How it works…

See also

Representing colors with hue, saturation, and brightness

How to do it…

How it works…

There's more…

Using colors for detection – skin tone detection

4. Counting the Pixels with Histograms

Introduction

Computing the image histogram

Getting started

How to do it...

How it works...

There's more...

Computing histograms of color images

See also

Applying look-up tables to modify the image appearance

How to do it...

How it works...

There's more...

Stretching a histogram to improve the image contrast

Applying a look-up table on color images

See also

Equalizing the image histogram

How to do it...

How it works...

Backprojecting a histogram to detect specific image content

How to do it...

How it works...

There's more...

Backprojecting color histograms

See also

Using the mean shift algorithm to find an object

How to do it...

How it works...

See also

Retrieving similar images using the histogram comparison

How to do it...

How it works...

See also

Counting pixels with integral images

How to do it...

How it works...

There's more...

Adaptive thresholding

Visual tracking using histograms

See also

5. Transforming Images with Morphological Operations

Introduction

Eroding and dilating images using morphological filters

Getting ready

How to do it...

How it works...

There's more...

See also

Opening and closing images using morphological filters

How to do it...

How it works...

See also

Detecting edges and corners using morphological filters

Getting ready

How to do it...

How it works...

See also

Segmenting images using watersheds

How to do it...

How it works...

There's more...

See also

Extracting distinctive regions using MSER

How to do it...

How it works...

See also

Extracting foreground objects with the GrabCut algorithm

How to do it...

How it works...

See also

6. Filtering the Images

Introduction

Filtering images using low-pass filters

How to do it...

How it works...

There's more...

Downsampling an image

Interpolating pixel values

See also

Filtering images using a median filter

How to do it...

How it works...

Applying directional filters to detect edges

How to do it...

How it works...

There's more...

Gradient operators

Gaussian derivatives

See also

Computing the Laplacian of an image

How to do it...

How it works...

There's more...

Enhancing the contrast of an image using the Laplacian

Difference of Gaussians

See also

7. Extracting Lines, Contours, and Components

Introduction

Detecting image contours with the Canny operator

How to do it...

How it works...

See also

Detecting lines in images with the Hough transform

Getting ready

How to do it...

How it works...

There's more...

Detecting circles

See also

Fitting a line to a set of points

How to do it...

How it works...

There's more...

Extracting the components' contours

How to do it...

How it works...

There's more...

Computing components' shape descriptors

How to do it...

How it works...

There's more...

Quadrilateral detection

8. Detecting Interest Points

Introduction

Detecting corners in an image

How to do it...

How it works...

There's more...

Good features to track

The feature detector's common interface

See also

Detecting features quickly

How to do it...

How it works...

There's more...

Adapted feature detection

Grid adapted feature detection

Pyramid adapted feature detection

See also

Detecting scale-invariant features

How to do it...

How it works...

There's more...

The SIFT feature-detection algorithm

See also

Detecting FAST features at multiple scales

How to do it...

How it works...

There's more...

The ORB feature-detection algorithm

See also

9. Describing and Matching Interest Points

Introduction

Matching local templates

How to do it...

How it works...

There's more...

Template matching

See also

Describing local intensity patterns

How to do it...

How it works...

There's more...

Cross-checking matches

The ratio test

Distance thresholding

See also

Describing keypoints with binary features

How to do it...

How it works...

There's more...

FREAK

See also

10. Estimating Projective Relations in Images

Introduction

Image formation

Calibrating a camera

How to do it...

How it works...

There's more...

Calibration with known intrinsic parameters

Using a grid of circles for calibration

See also

Computing the fundamental matrix of an image pair

Getting ready

How to do it...

How it works...

See also

Matching images using a random sample consensus

How to do it...

How it works...

There's more...

Refining the fundamental matrix

Refining the matches

Computing a homography between two images

Getting ready

How to do it...

How it works...

There's more...

Detecting planar targets in an image

See also

11. Processing Video Sequences

Introduction

Reading video sequences

How to do it...

How it works...

There's more...

See also

Processing the video frames

How to do it...

How it works...

There's more...

Processing a sequence of images

Using a frame processor class

See also

Writing video sequences

How to do it...

How it works...

There's more...

The codec four-character code

See also

Tracking feature points in a video

How to do it...

How it works...

See also

Extracting the foreground objects in a video

How to do it...

How it works...

There's more...

The Mixture of Gaussian method

See also

Index