Beginning Digital Image Processing

Using Free Tools for Photographers

Sebastian Montabone

Apress® Contents

Contents at a Glance iv

Contents ...v

About the Author xii

About the Technical Reviewer xiii

Acknowledgments .xiv

Introduction ...... xv

Chapter 1: Digital Photography ....1

Light and Photography 2 Digital Camera 5

Lens 6

Viewfinder or LCD Screen 7

Sensor 9

Storage 9

Controls 10

Creating a Photograph 11 Composition 11 Exposure 23

Post-Processing 29

Summary 30

Chapter 2: Digital Images 31

Vector Images vs. Raster Images 31

Resolution 32

Resolution for Computer Displays 32

Resolution for Printing 35 Aspect Ratio 36

Color 38

Color Depth 39 Color Spaces 40 File Formats 44

JPG 44

GIF 44

PNG 45

TIFF 45

OpenEXR 45

Which Format Should You Use? 45

Starting to Use the Tools 46 Changing File Formats with Gimp 46

Changing File Formats with ImageMagick 47

Summary 47 Chapter 3: Geometric Transforms 49 Resizing 49

Resizing Methods 50

Resizing with Gimp 51

Resizing with ImageMagick 53

Resizing Print Size 54

Cropping 55

Cropping with Gimp 59

Cropping with ImageMagick 63

Rotating 63

Rotating with Gimp 63

Rotating with ImageMagick 69 Flipping 69

Flipping with Gimp 70 Flipping with ImageMagick 70 Summary ., 70

Chapter 4: Color Transforms < 71

White Balance 71

with Adjusting White Balance Gimp , 73

Color Balance with Adjusting Gimp , 76

Brightness and Contrast 77

Hue and Saturation 81

Grayscale 85

Curves 85

Summary 96

Chapter 5: Filters ....97

Selecting a Region 97 Rectangle Select 98 Ellipse Select Tool 99

Free Select Tool 100

Fuzzy Select Tool 101

Select By Color 102 Intelligent Scissors Select Tool 103

Adding and Removing Regions 104

Editing the Selection 104

Blur 105

Simple Blur 105

Gaussian Blur 106

Motion Blur 109

Pixelize 111

Sharpness 113

Sharpen 113

Unsharp Mask 113

Noise Reduction 117 Artistic Filters 119

Old Photo 119

Softglow 120

Summary 121

Chapter 6: Photo Retouching , 123 Red-Eye Removal 123 Object Removal 126 Removing Objects with Gimp 127

Removing Objects with the Clone Tool 133

Removing Small Objects with the Healing Tool 136 Selective Colorization 137

Metadata 143

ExifTool 144

Reading Metadata.... 144

Modifying Metadata 147

Organizing Files Using Metadata 148

Summary 149

Chapter 7: HDR Imaging 151

Generating an HDR Image 153

Generating an HDR Image from One RAW File 153

Generating an HDR Image from Multiple Pictures 157 Generating the HDR Image with Qtpfsgui 160

Tone Mapping 165

Tone Mapping with Qtpfsgui 165

Mantiuk 167

Fattal 169

Drago 171

Durand 173

Reinhard '02 175

Reinhard'05 177 Ashikhmin 179

Pattanaik 181

Summary 183

Chapter 8: Correction 185

Lens Distortion Correction 185

Radial Distortion 185

Vignetting 187

Lens Distortion Correction with Gimp 188

Perspective Distortion Correction 194 Perspective Distortion Correction Using Gimp 196 Correcting Perspective Distortions with Shear 201

Summary 204 Chapter 9: Panorama Photo Stitching ....205

Capturing a Panorama 205 Image Projections 208 Creating Panoramas With 209 Regular Crop 215 Crop With Filling 216 Creating More Complex Panoramas 217

Other Projections 221

Creating a Metal Sphere With Hugin 222

Creating a Little Planet With Hugin 222

Creating a Little Planet With Gimp 223

Hugin Options - 225 Summary 234

Chapter 10: Movie Editing 235

User Interface 235

Frame Selection and Playback Options 235

Codecs and Video Formats 238 Frame Rate 239

Saving Your Project 240

Filters 240

Transform Filters 241

Color Filters 248

More Filters 250

Summary 251

Chapter 11: Canon Hack Development Kit 253

Installation 254

Creating the Files in 254

Creating the Files in Ubuntu 256

Asking the Camera for Its Firmware Version 256

in Shooting RAW , 258

Using Zebra Mode 259

Displaying Grids 261

Changing the Exposure time 262

Bracketing mode 263

Games and More 266

Running Scripts 270

Summary 273

Appendix: Installing the Tools 275

GIMP 275

Installing GIMP in Microsoft Windows 275

Installing GIMP in Ubuntu 275

UFRaw 275

Installing UFRaw in Microsoft Windows 275

Installing UFRaw in Ubuntu 276

Resyntheziser 276

Installing Resyntheziser in Microsoft Windows 276 Installing Resyntheziser in Ubuntu 278

Imagemagick 278

Installing Imagemagick in Microsoft Windows 278

Installing Imagemagick in Ubuntu 279

Hugin 279

Installing Hugin in Microsoft Windows 279

Installing Hugin in Ubuntu 279 Qtpfsgui 279

Installing Qtpfsgui in Microsoft Windows 279

Installing Qtpfsgui in Ubuntu 280

Avidemux - 280

Installing Avidemux in Microsoft Windows 280

Installing Avidemux in Ubuntu 280

ExifTool - 280

Installing ExifTool in Microsoft Windows 280 Installing ExifTool in Ubuntu 281

Index 283