The Book of GIMP - A Complete Guide to Nearly Everything

THE BOOK OF GIMP

gimp_FINAL_FINAL_pourPDF.indd 1 10/16/2012 11:45:48 AM

by Olivier Lecarme and Karine Delvare

San Francisco


Brief ContentsIntroduction . . . . . . . . . . . . . . . . . . . . . . . xv

Part I Learning GIMP1 Getting Started . . . . . . . . . . . . . . . . 3

2 Photograph Retouching . . . . . . . . . . . 25

3 Drawing and Illustration . . . . . . . . . . 61

4 Logos and Textures . . . . . . . . . . . . . 89

5 Composite Photography . . . . . . . . . . 115

6 Animation . . . . . . . . . . . . . . . . . . . 139

7 Image Preprocessing . . . . . . . . . . . . 161

8 Designing a Website . . . . . . . . . . . . 181

Part II Reference9 The GIMP Interface . . . . . . . . . . . . . 195

10 Display . . . . . . . . . . . . . . . . . . . . . 221

11 Layers . . . . . . . . . . . . . . . . . . . . . . 231

12 Color . . . . . . . . . . . . . . . . . . . . . . . 241

13 Selections . . . . . . . . . . . . . . . . . . . . 285

14 Masks . . . . . . . . . . . . . . . . . . . . . . 313

15 Drawing Tools . . . . . . . . . . . . . . . . . 329

16 Transformation Tools . . . . . . . . . . . . 369

17 Filters . . . . . . . . . . . . . . . . . . . . . . 391

18 Animation Tools . . . . . . . . . . . . . . . 475

19 Obtaining and Printing Images . . . . . 509

20 Image Formats . . . . . . . . . . . . . . . . 533

21 Scripts and Plug-ins . . . . . . . . . . . . . 547

22 Customizing GIMP . . . . . . . . . . . . . . 561

Part III AppendicesA Vision and Image Representation . . . . 591

B Tips and Hints for Selected Exercises . . 609

C Resources . . . . . . . . . . . . . . . . . . . . 613

D Frequently Asked Questions . . . . . . . . 619

E Installing GIMP . . . . . . . . . . . . . . . . 625

F Batch Processing . . . . . . . . . . . . . . . 629

Index . . . . . . . . . . . . . . . . . . . . . . . . . . 635

THE BOOK OF GIMP. Copyright 2013 by Olivier Lecarme and Karine Delvare.

All rights reserved. No part of this work may be reproduced or transmitted in any form or by any means,electronic or mechanical, including photocopying, recording, or by any information storage or retrievalsystem, without the prior written permission of the copyright owner and the publisher.

First printing

Printed in China

15 14 13 12 1 2 3 4 5 6 7 8 9

ISBN10: 1-59327-383-5ISBN13: 978-1-59327-383-5

Publisher: William PollockProduction Editor: Serena YangCover Illustration: Tina SalamehDevelopmental Editor: Sondra SilverhawkCopyeditor: LeeAnn PickrellProofreaders: Paula L. Fleming and Riley Hoffman

For information on book distributors or translations, please contact No Starch Press, Inc. directly:

No Starch Press, Inc.38 Ringold Street, San Francisco, CA 94103phone: 415.863.9900; fax: 415.863.9950; [email protected]; www.nostarch.com

Library of Congress Cataloging-in-Publication Data

Lecarme, Olivier.[GIMP. English]The book of GIMP : a complete guide to nearly everything / by Olivier Lecarmeand Karine Delvare.

pages cmIncludes bibliographical references and index.ISBN 978-1-59327-383-5 -- ISBN 1-59327-383-51. GIMP (Computer file) 2. Photography--Digital techniques. 3. Imageprocessing--Digital techniques. I. Delvare, Karine. II. Title.TR267.5.G56L4313 2012621.36'7--dc23

2012020781

No Starch Press and the No Starch Press logo are registered trademarks of No Starch Press, Inc. Other productand company names mentioned herein may be the trademarks of their respective owners. Rather than use atrademark symbol with every occurrence of a trademarked name, we are using the names only in an editorialfashion and to the benefit of the trademark owner, with no intention of infringement of the trademark.

The information in this book is distributed on an As Is basis, without warranty. While every precaution hasbeen taken in the preparation of this work, neither the author nor No Starch Press, Inc. shall have any liabilityto any person or entity with respect to any loss or damage caused or alleged to be caused directly or indirectlyby the information contained in it.


Brief ContentsIntroduction . . . . . . . . . . . . . . . . . . . . . . . xv

Part I Learning GIMP1 Getting Started . . . . . . . . . . . . . . . . 3

2 Photograph Retouching . . . . . . . . . . . 25

3 Drawing and Illustration . . . . . . . . . . 61

4 Logos and Textures . . . . . . . . . . . . . 89

5 Composite Photography . . . . . . . . . . 115

6 Animation . . . . . . . . . . . . . . . . . . . 139

7 Image Preprocessing . . . . . . . . . . . . 161

8 Designing a Website . . . . . . . . . . . . 181

Part II Reference9 The GIMP Interface . . . . . . . . . . . . . 195

10 Display . . . . . . . . . . . . . . . . . . . . . 221

11 Layers . . . . . . . . . . . . . . . . . . . . . . 231

12 Color . . . . . . . . . . . . . . . . . . . . . . . 241

13 Selections . . . . . . . . . . . . . . . . . . . . 285

14 Masks . . . . . . . . . . . . . . . . . . . . . . 313

15 Drawing Tools . . . . . . . . . . . . . . . . . 329

16 Transformation Tools . . . . . . . . . . . . 369

17 Filters . . . . . . . . . . . . . . . . . . . . . . 391

18 Animation Tools . . . . . . . . . . . . . . . 475

19 Obtaining and Printing Images . . . . . 509

20 Image Formats . . . . . . . . . . . . . . . . 533

21 Scripts and Plug-ins . . . . . . . . . . . . . 547

22 Customizing GIMP . . . . . . . . . . . . . . 561

Part III AppendicesA Vision and Image Representation . . . . 591

B Tips and Hints for Selected Exercises . . 609

C Resources . . . . . . . . . . . . . . . . . . . . 613

D Frequently Asked Questions . . . . . . . . 619

E Installing GIMP . . . . . . . . . . . . . . . . 625

F Batch Processing . . . . . . . . . . . . . . . 629

Index . . . . . . . . . . . . . . . . . . . . . . . . . . 635

THE BOOK OF GIMP. Copyright 2013 by Olivier Lecarme and Karine Delvare.

All rights reserved. No part of this work may be reproduced or transmitted in any form or by any means,electronic or mechanical, including photocopying, recording, or by any information storage or retrievalsystem, without the prior written permission of the copyright owner and the publisher.

First printing

Printed in China

15 14 13 12 1 2 3 4 5 6 7 8 9

ISBN10: 1-59327-383-5ISBN13: 978-1-59327-383-5

Publisher: William PollockProduction Editor: Serena YangCover Illustration: Tina SalamehDevelopmental Editor: Sondra SilverhawkCopyeditor: LeeAnn PickrellProofreaders: Paula L. Fleming and Riley Hoffman

For information on book distributors or translations, please contact No Starch Press, Inc. directly:

No Starch Press, Inc.38 Ringold Street, San Francisco, CA 94103phone: 415.863.9900; fax: 415.863.9950; [email protected]; www.nostarch.com

Library of Congress Cataloging-in-Publication Data

Lecarme, Olivier.[GIMP. English]The book of GIMP : a complete guide to nearly everything / by Olivier Lecarmeand Karine Delvare.

pages cmIncludes bibliographical references and index.ISBN 978-1-59327-383-5 -- ISBN 1-59327-383-5

1. GIMP (Computer file) 2. Photography--Digital techniques. 3. Imageprocessing--Digital techniques. I. Delvare, Karine. II. Title.TR267.5.G56L4313 2012621.36'7--dc23

2012020781

No Starch Press and the No Starch Press logo are registered trademarks of No Starch Press, Inc. Other productand company names mentioned herein may be the trademarks of their respective owners. Rather than use atrademark symbol with every occurrence of a trademarked name, we are using the names only in an editorialfashion and to the benefit of the trademark owner, with no intention of infringement of the trademark.

The information in this book is distributed on an As Is basis, without warranty. While every precaution hasbeen taken in the preparation of this work, neither the author nor No Starch Press, Inc. shall have any liabilityto any person or entity with respect to any loss or damage caused or alleged to be caused directly or indirectlyby the information contained in it.


Contents in DetailIntroduction . . . . . . . . . . . . . . . . . . . . . xv

This Book . . . . . . . . . . . . . . . . . . xvThe Authors . . . . . . . . . . . . . . . . xviProduction Notes . . . . . . . . . . . . . xviiConventions . . . . . . . . . . . . . . . . xviiAcknowledgments . . . . . . . . . . . . xvii

Part I Learning GIMP1 Getting Started . . . . . . . . . . . . . . 3

1.1 GIMP Basics . . . . . . . . . . . . . . . . 3The Screen Layout . . . . . . . . . . . . 3Dockable Dialogs . . . . . . . . . . . . 4The Toolbox . . . . . . . . . . . . . . . . 6The Single-Window Interface . . . . . 6

1.2 Image Handling Basics . . . . . . . . . 8Opening an Image . . . . . . . . . . . . 8Maximizing an Image . . . . . . . . . 9Scanning . . . . . . . . . . . . . . . . . . 10Image Window Menus . . . . . . . . . 11Zooming . . . . . . . . . . . . . . . . . . 13Saving an Image . . . . . . . . . . . . . 13

1.3 Working with Images . . . . . . . . . . 15Resizing an Image . . . . . . . . . . . . 15Cropping an Image . . . . . . . . . . . 15Adding a Frame with Filters . . . . . . 17Using Layers . . . . . . . . . . . . . . . . 18Drawing in GIMP . . . . . . . . . . . . . 19Printing with GIMP . . . . . . . . . . . . 20

1.4 Using a Tablet . . . . . . . . . . . . . . . 21Installing a Tablet . . . . . . . . . . . . . 22The Tablet Mouse and Stylus . . . . . 22Working with a Tablet in GIMP . . . 23

1.5 Exercises . . . . . . . . . . . . . . . . . . 24

2 Photograph Retouching . . . . . . . 25

2.1 Tutorial: Enhancing Badly TakenPhotographs . . . . . . . . . . . . . . . . 25Cropping, Straightening, and

Restoring Perspective . . . . . 25Correcting Exposure . . . . . . . . . . . 26Correcting the Color Balance . . . . . 28Removing an Object . . . . . . . . . . . 29Improving Sharpness . . . . . . . . . . 30Removing Red Eye . . . . . . . . . . . . 30

2.2 Global Transformations . . . . . . . . . 32Resizing an Image . . . . . . . . . . . . 32Shearing an Image . . . . . . . . . . . 33Changing Brightness, Contrast, and

Levels . . . . . . . . . . . . . . . 34Adjusting Colors . . . . . . . . . . . . . 36

2.3 Local Transformations . . . . . . . . . . 38Making a Selection . . . . . . . . . . . 38Modifying Sharpness . . . . . . . . . . 41Modifying Brightness . . . . . . . . . . 42Using the Clone Tool . . . . . . . . . . 45Perspective Cloning . . . . . . . . . . . 46More Correction Methods for Red Eye 47Changing the Sky of a Landscape . . 49

2.4 Retouching a Scanned Photograph . 50Correcting Colors . . . . . . . . . . . . 50Correcting Scratches and Spots . . . 53Restoring Very Old Photographs . . . 54

2.5 Advanced Techniques . . . . . . . . . . 55Making a Photograph Look Older . . 55Improving a Portrait . . . . . . . . . . . 57


Contents in Detail 0 ix

The Move Path Tool . . . . . . . . . . . 156Binocular Animation . . . . . . . . . . . 156Improving the Binocular Animation . 158

6.5 Exercises . . . . . . . . . . . . . . . . . . 160

7 Image Preprocessing . . . . . . . . . 161

7.1 Tutorial: Extracting Informationfrom a Picture . . . . . . . . . . . . . . . 161Dynamics Extension . . . . . . . . . . . 161Histogram Modification . . . . . . . . 163Noise Reduction . . . . . . . . . . . . . 164Edge Detection . . . . . . . . . . . . . . 164

7.2 The Principles of Preprocessing . . . . 165Subjective Aspects of Preprocessing 165Histograms and Decomposition into

Channels . . . . . . . . . . . . . 166Extracting Information through

Dynamics Extension . . . . . . 1687.3 Filtering . . . . . . . . . . . . . . . . . . . 171

The Principles of Filtering . . . . . . . . 171Characteristic Matrices . . . . . . . . . 172Comparing the Built-in Filters . . . . . 173

7.4 Edge Detection . . . . . . . . . . . . . . 175The Principles of Edge Detection . . . 175Edge Detection Methods . . . . . . . . 176

7.5 Exercises . . . . . . . . . . . . . . . . . . 179

8 Designing a Website . . . . . . . . . 181

8.1 Tutorial: Laying Out a Website . . . . 181Planning . . . . . . . . . . . . . . . . . . 181Layout . . . . . . . . . . . . . . . . . . . . 182Adding Color . . . . . . . . . . . . . . . 182Choosing a Color Palette . . . . . . . . 183

8.2 Fixed- and Variable-Width Designs 1858.3 Web Design Tools . . . . . . . . . . . . 186

Image Map . . . . . . . . . . . . . . . . . 186Semi-Flatten . . . . . . . . . . . . . . . . 189Slice . . . . . . . . . . . . . . . . . . . . . 189

8.4 Optimizing Images for the Web . . . 190JPEG . . . . . . . . . . . . . . . . . . . . . 191GIF . . . . . . . . . . . . . . . . . . . . . . 191PNG . . . . . . . . . . . . . . . . . . . . . 191Transparency . . . . . . . . . . . . . . . 191

8.5 Exercises . . . . . . . . . . . . . . . . . . 192

Part II Reference9 The GIMP Interface . . . . . . . . . . 1959.1 The Main Windows . . . . . . . . . . . 195

Multi-Window Mode . . . . . . . . . . 195Single-Window Mode . . . . . . . . . 197Docking Windows and Dockable

Dialogs . . . . . . . . . . . . . . 198The Image Window . . . . . . . . . . . 202

9.2 Fundamental GIMP Commands . . . 203Closing Windows and Quitting GIMP 203Working with Multiple Images . . . . 204Common Tab Menu Options . . . . . 206

9.3 Working with the GIMP Interface . . 207Menus . . . . . . . . . . . . . . . . . . . . 207Keyboard Shortcuts . . . . . . . . . . . 207Keyboard Tips . . . . . . . . . . . . . . . 209Clicking and Dragging . . . . . . . . . 209

9.4 Creating, Loading, Saving, andExporting Files . . . . . . . . . . . . . . 210Creating a New Image . . . . . . . . . 210Loading a Web Page as an Image . 211Loading an Image from a File . . . . 212Saving an Image . . . . . . . . . . . . . 214Exporting an Image . . . . . . . . . . . 215

9.5 Undoing . . . . . . . . . . . . . . . . . . . 2179.6 The GIMP Help System . . . . . . . . . 219

10 Display . . . . . . . . . . . . . . . . . . . . 22110.1 Rulers and Units . . . . . . . . . . . . . 22110.2 Guides . . . . . . . . . . . . . . . . . . . . 22310.3 Grids . . . . . . . . . . . . . . . . . . . . . 22510.4 Zoom . . . . . . . . . . . . . . . . . . . . . 22610.5 Using Multiple Views . . . . . . . . . . 229

11 Layers . . . . . . . . . . . . . . . . . . . . . 23111.1 The Layers Dialog . . . . . . . . . . . . 231

Components of the Layers Dialog . . 231A Layer Entry in the Layers Dialog . 233Keyboard Shortcuts in the Layers

Dialog . . . . . . . . . . . . . . . 234Uses of the Layers Dialog . . . . . . . 234

11.2 The Layers Menu . . . . . . . . . . . . . 23411.3 Layer Groups . . . . . . . . . . . . . . . 23611.4 The Image: Layer Menu . . . . . . . . 238

The Stack Menu . . . . . . . . . . . . . . 239

viii Contents in Detail

Using Multiple Captures of theSame Scene . . . . . . . . . . . 58

2.6 Exercises . . . . . . . . . . . . . . . . . . 60

3 Drawing and Illustration . . . . . . 613.1 Tutorial: Colorizing a Drawing . . . . 61

The Black and White Drawing . . . . 61Using Layers to Keep Outlines Visible 61Defining Objects and Base Colors . . 63Coloring the Mushrooms . . . . . . . . 64Shading . . . . . . . . . . . . . . . . . . . 65Finishing Touches . . . . . . . . . . . . . 67

3.2 Painting and Drawing . . . . . . . . . . 68Brushes . . . . . . . . . . . . . . . . . . . 68The Pencil Tool . . . . . . . . . . . . . . 69The Paintbrush Tool . . . . . . . . . . . 71The Airbrush Tool . . . . . . . . . . . . 72The Ink Tool . . . . . . . . . . . . . . . . 73

3.3 Filling an Area . . . . . . . . . . . . . . 73The Bucket Fill Tool . . . . . . . . . . . . 73Gradients . . . . . . . . . . . . . . . . . . 74Patterns . . . . . . . . . . . . . . . . . . . 75

3.4 Dodging, Burning, and Smudging . 75The Dodge/Burn Tool . . . . . . . . . . 75The Smudge Tool . . . . . . . . . . . . . 76

3.5 The Digital Painting Process . . . . . . 78Composition . . . . . . . . . . . . . . . . 78Sky and Clouds . . . . . . . . . . . . . . 79Mountains . . . . . . . . . . . . . . . . . 80Hills . . . . . . . . . . . . . . . . . . . . . . 81Grassland . . . . . . . . . . . . . . . . . 81Trees . . . . . . . . . . . . . . . . . . . . . 82River . . . . . . . . . . . . . . . . . . . . . 84

3.6 Drawing Shapes . . . . . . . . . . . . . 85Drawing a Straight Line . . . . . . . . 85Drawing Ellipses and Rectangles . . . 86Drawing a Complex Shape . . . . . . 87

3.7 Exercises . . . . . . . . . . . . . . . . . . 88

4 Logos and Textures . . . . . . . . . . 894.1 Tutorial: Making a Luggage Tag . . . 894.2 Textures . . . . . . . . . . . . . . . . . . . 92

Tiling . . . . . . . . . . . . . . . . . . . . . 93Creating Textures . . . . . . . . . . . . . 95Using the Blend Tool . . . . . . . . . . . 96Using the Noise Filters . . . . . . . . . 101

Using the Embossing Filters . . . . . . 102More Ways to Create Textures . . . . 105

4.3 Logos . . . . . . . . . . . . . . . . . . . . 108The Text Tool . . . . . . . . . . . . . . . . 108Adding Relief . . . . . . . . . . . . . . . 108Proper Shade vs. Cast Shadow . . . 109Applying a Texture . . . . . . . . . . . 111

4.4 Exercises . . . . . . . . . . . . . . . . . . 113

5 Composite Photography . . . . . . 1155.1 Tutorial: Building a Composite

Portrait . . . . . . . . . . . . . . . . . . . 115Taking Features from Different

Portraits . . . . . . . . . . . . . . 116Smoothing Transitions . . . . . . . . . . 118

5.2 Selections, Overlaying, andBlending Modes . . . . . . . . . . . . . 119Masks and Selections . . . . . . . . . . 119Overlaying Images . . . . . . . . . . . . 121Using Blending Modes . . . . . . . . . 123

5.3 Building a Panorama . . . . . . . . . . 127Taking the Pictures . . . . . . . . . . . . 127Superimposing the Pictures . . . . . . 128Touching Up the Panorama . . . . . . 129The Pandora Plug-in . . . . . . . . . . . 131

5.4 Image Overlaying . . . . . . . . . . . . 131Digital Collage . . . . . . . . . . . . . . 131Self-Compositing . . . . . . . . . . . . . 134A Composite Photography Project . . 136

5.5 Exercises . . . . . . . . . . . . . . . . . . 138

6 Animation . . . . . . . . . . . . . . . . . . 1396.1 Tutorial: Animated Text . . . . . . . . . 139

Method One: Frame by Frame . . . . 139Method Two: Filtering All Layers . . . 140Method Three: Moving Along a Path 142

6.2 Building an Animated GIF by Hand 144Drawing a Rainbow Daisy . . . . . . . 145Zooming Toward the Viewer . . . . . 146Adding Rain to a Landscape . . . . . 148Adding Snow to a Landscape . . . . 150

6.3 Using Animation Tools . . . . . . . . . 151Interactive Deformation . . . . . . . . . 151Animating a Still Image . . . . . . . . 151Morphing . . . . . . . . . . . . . . . . . . 153

6.4 Using GAP . . . . . . . . . . . . . . . . . 155


Contents in Detail 0 xi

The Eraser Tool . . . . . . . . . . . . . . 345The Airbrush Tool . . . . . . . . . . . . 346The Ink Tool . . . . . . . . . . . . . . . . 347

15.6 The Cloning Tools . . . . . . . . . . . . 348The Clone Tool . . . . . . . . . . . . . . 348The Heal Tool . . . . . . . . . . . . . . . 350The Perspective Clone Tool . . . . . . 350

15.7 The Modifying Tools . . . . . . . . . . . 351The Convolve Tool . . . . . . . . . . . . 351The Smudge Tool . . . . . . . . . . . . . 352The Dodge/Burn Tool . . . . . . . . . . 352

15.8 The Text Tool . . . . . . . . . . . . . . . . 353The Text Tool Options . . . . . . . . . . 353Choosing a Font . . . . . . . . . . . . . 355Using the Text Tool . . . . . . . . . . . . 356Editing Your Text . . . . . . . . . . . . . 357

15.9 The Color Picker Tool and theMeasure Tool . . . . . . . . . . . . . . . 358The Color Picker Tool . . . . . . . . . . 359The Measure Tool . . . . . . . . . . . . 360

15.10 Combining Tool Presets, Brushes,and Paint Dynamics . . . . . . . . . . . 361Getting to Know the Dialogs Involved 361Predefined Paint Dynamics . . . . . . 361Predefined Brushes . . . . . . . . . . . . 363Predefined Tool Presets . . . . . . . . . 364

16 Transformation Tools . . . . . . . . . 369

16.1 Global Transformations . . . . . . . . . 369Transforming an Image . . . . . . . . . 369Resizing an Image . . . . . . . . . . . . 371Cropping an Image . . . . . . . . . . . 374Transforming a Layer . . . . . . . . . . 375

16.2 Local Transformations . . . . . . . . . . 377Shared Properties . . . . . . . . . . . . 377The Move Tool . . . . . . . . . . . . . . . 381The Align Tool . . . . . . . . . . . . . . . 381The Crop Tool . . . . . . . . . . . . . . . 384The Rotate Tool . . . . . . . . . . . . . . 385The Scale Tool . . . . . . . . . . . . . . . 386The Shear Tool . . . . . . . . . . . . . . 387The Perspective Tool . . . . . . . . . . . 387The Flip Tool . . . . . . . . . . . . . . . . 388The Cage Transform Tool . . . . . . . 388

17 Filters . . . . . . . . . . . . . . . . . . . . . 39117.1 Common Properties . . . . . . . . . . . 39117.2 The Blur Filters . . . . . . . . . . . . . . . 393

Blur . . . . . . . . . . . . . . . . . . . . . . 393Gaussian Blur . . . . . . . . . . . . . . . 393Motion Blur . . . . . . . . . . . . . . . . . 394Pixelize . . . . . . . . . . . . . . . . . . . 395Selective Gaussian Blur . . . . . . . . . 396Tileable Blur . . . . . . . . . . . . . . . . 396

17.3 The Enhance Filters . . . . . . . . . . . 397Antialias . . . . . . . . . . . . . . . . . . 397Deinterlace . . . . . . . . . . . . . . . . . 397Despeckle . . . . . . . . . . . . . . . . . . 398Destripe . . . . . . . . . . . . . . . . . . . 400NL Filter . . . . . . . . . . . . . . . . . . . 400Red Eye Removal . . . . . . . . . . . . . 401Sharpen . . . . . . . . . . . . . . . . . . . 402Unsharp Mask . . . . . . . . . . . . . . . 402

17.4 The Distorts Filters . . . . . . . . . . . . 404Apply Lens . . . . . . . . . . . . . . . . . 404Curve Bend . . . . . . . . . . . . . . . . . 404Emboss . . . . . . . . . . . . . . . . . . . 405Engrave . . . . . . . . . . . . . . . . . . . 405IWarp . . . . . . . . . . . . . . . . . . . . 406Lens Distortion . . . . . . . . . . . . . . . 406Mosaic . . . . . . . . . . . . . . . . . . . 408Newsprint . . . . . . . . . . . . . . . . . 408Pagecurl . . . . . . . . . . . . . . . . . . . 409Polar Coordinates . . . . . . . . . . . . 410Ripple . . . . . . . . . . . . . . . . . . . . 411Shift . . . . . . . . . . . . . . . . . . . . . 411Value Propagate . . . . . . . . . . . . . 412Waves . . . . . . . . . . . . . . . . . . . . 414Whirl and Pinch . . . . . . . . . . . . . 414Wind . . . . . . . . . . . . . . . . . . . . . 414

17.5 The Light and Shadow Filters . . . . . 415Gradient Flare . . . . . . . . . . . . . . . 415Lens Flare . . . . . . . . . . . . . . . . . . 418Lighting Effects . . . . . . . . . . . . . . 418Sparkle . . . . . . . . . . . . . . . . . . . 420Supernova . . . . . . . . . . . . . . . . . 421Drop Shadow . . . . . . . . . . . . . . . 421Perspective . . . . . . . . . . . . . . . . . 422

17.6 The Noise Filters . . . . . . . . . . . . . 423HSV Noise . . . . . . . . . . . . . . . . . 423

x Contents in Detail

The Mask, Transparency, andTransform Menus . . . . . . . . 239

The Final Five Entries . . . . . . . . . . 240

12 Color . . . . . . . . . . . . . . . . . . . . . . 24112.1 Concepts . . . . . . . . . . . . . . . . . . 241

Color Models . . . . . . . . . . . . . . . 241Stored Representations . . . . . . . . . 242Indexed Mode . . . . . . . . . . . . . . . 243

12.2 Blending Modes . . . . . . . . . . . . . 244Modes That Leave Pixels Intact . . . . 245Lightening Modes . . . . . . . . . . . . 246Darkening Modes . . . . . . . . . . . . 247Luminosity Modes . . . . . . . . . . . . 248Color Distortion Modes . . . . . . . . . 249HSV Modes . . . . . . . . . . . . . . . . 251

12.3 Color Management . . . . . . . . . . . 252Color-Managed Workflow . . . . . . 252Using Color Management . . . . . . . 254

12.4 The Major Color Tools . . . . . . . . . 254The Color Chooser . . . . . . . . . . . . 254Levels . . . . . . . . . . . . . . . . . . . . 258Curves . . . . . . . . . . . . . . . . . . . . 261

12.5 Additional Color Tools . . . . . . . . . 263Color Balance . . . . . . . . . . . . . . . 263Hue-Saturation . . . . . . . . . . . . . . 264Colorize . . . . . . . . . . . . . . . . . . . 265Brightness-Contrast . . . . . . . . . . . 265Threshold . . . . . . . . . . . . . . . . . . 266Posterize . . . . . . . . . . . . . . . . . . 266Desaturate . . . . . . . . . . . . . . . . . 266Inversion . . . . . . . . . . . . . . . . . . 267

12.6 The Color Submenus . . . . . . . . . . 268The Auto Submenu . . . . . . . . . . . . 268The Components Submenu . . . . . . 270The Map Submenu . . . . . . . . . . . . 274The Info Submenu . . . . . . . . . . . . 278The Remaining Color Tools . . . . . . 280

13 Selections . . . . . . . . . . . . . . . . . . 28513.1 What Is a Selection? . . . . . . . . . . . 285

A Selection as an Outline . . . . . . . 285A Selection as a Grayscale Image . 286

13.2 The Seven Selection Tools . . . . . . . 287Common Options . . . . . . . . . . . . 287The Rectangle Select Tool . . . . . . . 289

The Ellipse Select Tool . . . . . . . . . . 292The Free Select Tool . . . . . . . . . . . 293The Fuzzy Select Tool . . . . . . . . . . 294The Select by Color Tool . . . . . . . . 296The Scissors Select Tool . . . . . . . . . 296The Foreground Select Tool . . . . . . 298

13.3 The Paths Tool . . . . . . . . . . . . . . . 300Building a Path . . . . . . . . . . . . . . 300Modifying a Path . . . . . . . . . . . . . 301Using a Path . . . . . . . . . . . . . . . . 303The Paths Dialog . . . . . . . . . . . . . 305

13.4 Using Selections . . . . . . . . . . . . . 306The Select Menu . . . . . . . . . . . . . 307The Edit Menu . . . . . . . . . . . . . . . 310Modifying the Selection Border . . . . 312

14 Masks . . . . . . . . . . . . . . . . . . . . . 31314.1 Selection Masks . . . . . . . . . . . . . . 313

The Channels Dialog . . . . . . . . . . 313Creating a Selection Mask . . . . . . . 316The Quick Mask Tool . . . . . . . . . . 317

14.2 Layer Masks . . . . . . . . . . . . . . . . 318Building a Layer Mask . . . . . . . . . 318Manipulating a Layer Mask . . . . . . 319Using a Layer Mask . . . . . . . . . . . 321

14.3 Using Masks and Channels . . . . . . 323Building a Natural Mask . . . . . . . . 323Transparency and the Alpha Channel 324Converting Masks, Selections, and

Channels . . . . . . . . . . . . . 327

15 Drawing Tools . . . . . . . . . . . . . . 32915.1 Digital Art . . . . . . . . . . . . . . . . . 32915.2 An Overview of the Drawing Tools . 32915.3 Shared Features . . . . . . . . . . . . . 330

Drawing Tool Options . . . . . . . . . 330Paint Dynamics . . . . . . . . . . . . . . 333Using Dockable Dialogs with

Drawing Tools . . . . . . . . . 335Six Useful Dockable Dialogs . . . . . 337

15.4 The Fill Tools . . . . . . . . . . . . . . . . 339The Bucket Fill Tool . . . . . . . . . . . . 339The Blend Tool . . . . . . . . . . . . . . . 340

15.5 The Painting Tools . . . . . . . . . . . . 343The Pencil Tool . . . . . . . . . . . . . . 343The Paintbrush Tool . . . . . . . . . . . 344


Contents in Detail 0 xiii

Manipulating Frames . . . . . . . . . . 493Converting Between File Formats . . 494Modifying Frames . . . . . . . . . . . . 495Altering Layers . . . . . . . . . . . . . . 497Converting Between Multilayer and

Multiframe . . . . . . . . . . . . 497Encoding . . . . . . . . . . . . . . . . . . 499Playback and Navigator . . . . . . . . 500Split Video into Frames . . . . . . . . . 502Bluebox . . . . . . . . . . . . . . . . . . . 503Onionskin . . . . . . . . . . . . . . . . . 504Storyboard . . . . . . . . . . . . . . . . . 505

19 Obtaining and Printing Images 50919.1 Capturing Screenshots . . . . . . . . . 50919.2 Scanning . . . . . . . . . . . . . . . . . . 510

Scanners and Drivers . . . . . . . . . . 510XSane and GIMP . . . . . . . . . . . . . 512Selecting an Area to Scan . . . . . . . 512Setting the Scanning Parameters . . . 514Scan Modes . . . . . . . . . . . . . . . . 515Scanning Resolutions . . . . . . . . . . 517Color Handling . . . . . . . . . . . . . . 518

19.3 Digital Cameras . . . . . . . . . . . . . 520Importing Photographs into GIMP . . 520Choosing a Format . . . . . . . . . . . 521Handling Raw Photographs . . . . . . 523

19.4 Printing . . . . . . . . . . . . . . . . . . . 525The Principles of Printing . . . . . . . . 525Printing with the GTK Interface . . . . 527Printing with Gutenprint . . . . . . . . 529

19.5 Scanning and Printing with Windows 531

20 Image Formats . . . . . . . . . . . . . . 53320.1 An Overview of File Formats . . . . . 533

Raster and Vector Formats . . . . . . . 533Lossless and Lossy Compression . . . 534Layout Engines and Browsers . . . . . 536

20.2 JPEG, GIF, and PNG . . . . . . . . . . 537JPEG . . . . . . . . . . . . . . . . . . . . . 537GIF . . . . . . . . . . . . . . . . . . . . . . 538PNG . . . . . . . . . . . . . . . . . . . . . 541

20.3 GIMPs Native Formats . . . . . . . . . 542XCF . . . . . . . . . . . . . . . . . . . . . . 542Other Native Formats . . . . . . . . . . 543

20.4 Other Useful Formats . . . . . . . . . . 543

PostScript and PDF . . . . . . . . . . . . 544TIFF . . . . . . . . . . . . . . . . . . . . . . 545Netpbm Formats . . . . . . . . . . . . . 545SVG . . . . . . . . . . . . . . . . . . . . . 546Additional Formats Supported by

GIMP . . . . . . . . . . . . . . . 546

21 Scripts and Plug-ins . . . . . . . . . . 547

21.1 About Scripts and Plug-ins . . . . . . . 547Scheme, Python, and C . . . . . . . . . 547Installed Plug-ins . . . . . . . . . . . . . 548Finding New Plug-ins . . . . . . . . . . 549

21.2 Noteworthy Plug-ins . . . . . . . . . . . 549Photo Effects . . . . . . . . . . . . . . . . 550GMIC . . . . . . . . . . . . . . . . . . . . 550Liquid Rescale . . . . . . . . . . . . . . . 550Elsamuko Scripts . . . . . . . . . . . . . 553

21.3 Writing Plug-ins . . . . . . . . . . . . . 554Scheme . . . . . . . . . . . . . . . . . . . 554Python . . . . . . . . . . . . . . . . . . . . 556C . . . . . . . . . . . . . . . . . . . . . . . 558

22 Customizing GIMP . . . . . . . . . . . 561

22.1 The Preferences Dialog . . . . . . . . . 561Environment . . . . . . . . . . . . . . . . 561User Interface . . . . . . . . . . . . . . . 562Theme . . . . . . . . . . . . . . . . . . . . 563Help System . . . . . . . . . . . . . . . . 563Tool Options . . . . . . . . . . . . . . . . 563Toolbox . . . . . . . . . . . . . . . . . . . 564Default New Image . . . . . . . . . . . 564Default Image Grid . . . . . . . . . . . 565Image Windows . . . . . . . . . . . . . 565Display . . . . . . . . . . . . . . . . . . . 567Color Management . . . . . . . . . . . 567Input Devices . . . . . . . . . . . . . . . 569Window Management . . . . . . . . . 569Folders . . . . . . . . . . . . . . . . . . . . 571

22.2 Additional Preferences in the EditMenu . . . . . . . . . . . . . . . . . . . . . 571Keyboard Shortcuts . . . . . . . . . . . 571Modules . . . . . . . . . . . . . . . . . . . 572Units . . . . . . . . . . . . . . . . . . . . . 573

22.3 Customizing Image Views . . . . . . . 573Display Filters . . . . . . . . . . . . . . . 573

xii Contents in Detail

Hurl . . . . . . . . . . . . . . . . . . . . . . 423Pick . . . . . . . . . . . . . . . . . . . . . . 424RGB Noise . . . . . . . . . . . . . . . . . 424Slur . . . . . . . . . . . . . . . . . . . . . . 425Spread . . . . . . . . . . . . . . . . . . . 425

17.7 The Edge-Detect Filters . . . . . . . . . 426Difference of Gaussians . . . . . . . . 426Edge . . . . . . . . . . . . . . . . . . . . . 426Laplace . . . . . . . . . . . . . . . . . . . 427Neon . . . . . . . . . . . . . . . . . . . . . 428Sobel . . . . . . . . . . . . . . . . . . . . . 428

17.8 The Generic Filters . . . . . . . . . . . . 429Convolution Matrix . . . . . . . . . . . 429Dilate . . . . . . . . . . . . . . . . . . . . 430Erode . . . . . . . . . . . . . . . . . . . . 430

17.9 The Combine Filters . . . . . . . . . . . 430Depth Merge . . . . . . . . . . . . . . . . 430

17.10 The Artistic Filters . . . . . . . . . . . . . 431Apply Canvas . . . . . . . . . . . . . . . 432Cartoon . . . . . . . . . . . . . . . . . . . 432Clothify . . . . . . . . . . . . . . . . . . . 433Cubism . . . . . . . . . . . . . . . . . . . 433GIMPressionist . . . . . . . . . . . . . . 434Glass Tile . . . . . . . . . . . . . . . . . . 438Oilify . . . . . . . . . . . . . . . . . . . . . 438Photocopy . . . . . . . . . . . . . . . . . 439Softglow . . . . . . . . . . . . . . . . . . . 440Van Gogh . . . . . . . . . . . . . . . . . 440Weave . . . . . . . . . . . . . . . . . . . . 441

17.11 The Decor Filters . . . . . . . . . . . . . 442Add Bevel . . . . . . . . . . . . . . . . . 442Add Border . . . . . . . . . . . . . . . . 442Coffee Stain . . . . . . . . . . . . . . . . 443Fuzzy Border . . . . . . . . . . . . . . . 443Old Photo . . . . . . . . . . . . . . . . . . 443Round Corners . . . . . . . . . . . . . . 444

17.12 The Map Filters . . . . . . . . . . . . . . 444Bump Map . . . . . . . . . . . . . . . . . 444Displace . . . . . . . . . . . . . . . . . . . 445Fractal Trace . . . . . . . . . . . . . . . . 447Illusion . . . . . . . . . . . . . . . . . . . . 447Make Seamless . . . . . . . . . . . . . . 447Map Object . . . . . . . . . . . . . . . . 448Paper Tile . . . . . . . . . . . . . . . . . . 449Small Tiles . . . . . . . . . . . . . . . . . 451

Tile . . . . . . . . . . . . . . . . . . . . . . 451Warp . . . . . . . . . . . . . . . . . . . . 452

17.13 The Render Filters . . . . . . . . . . . . 453Clouds Filters . . . . . . . . . . . . . . . 453Nature Filters . . . . . . . . . . . . . . . 454Pattern Filters . . . . . . . . . . . . . . . 458Circuit . . . . . . . . . . . . . . . . . . . . 466Fractal Explorer . . . . . . . . . . . . . . 466Gfig . . . . . . . . . . . . . . . . . . . . . 468Lava . . . . . . . . . . . . . . . . . . . . . 470Line Nova . . . . . . . . . . . . . . . . . . 471Sphere Designer . . . . . . . . . . . . . 471Spyrogimp . . . . . . . . . . . . . . . . . 472

18 Animation Tools . . . . . . . . . . . . . 475

18.1 Principles of Animation . . . . . . . . . 475Frame Frequency and Vision . . . . . 475Frames and Layers . . . . . . . . . . . . 476Output Formats . . . . . . . . . . . . . . 476Optimizing Animations . . . . . . . . . 477

18.2 Tools for Building MultilayerAnimations . . . . . . . . . . . . . . . . . 478Animating by Hand . . . . . . . . . . . 478The IWarp Tool . . . . . . . . . . . . . . 478The Morph Tool . . . . . . . . . . . . . . 478Filtering All Layers . . . . . . . . . . . . 481

18.3 The Animation Menu . . . . . . . . . . 483Blend . . . . . . . . . . . . . . . . . . . . . 483Burn-In . . . . . . . . . . . . . . . . . . . . 483Rippling . . . . . . . . . . . . . . . . . . . 484Selection to Animimage . . . . . . . . 485Spinning Globe . . . . . . . . . . . . . . 485Waves . . . . . . . . . . . . . . . . . . . . 486Optimizing and Playing an

Animation . . . . . . . . . . . . 48618.4 The Move Path Tool . . . . . . . . . . . 487

Choosing the Source Layers . . . . . . 488Choosing the Destination Frames . . 489Applying Transformations . . . . . . . 489Control Points . . . . . . . . . . . . . . . 490Key Frames . . . . . . . . . . . . . . . . . 492The Preview Window . . . . . . . . . . 492Testing the Move Path Tool . . . . . . 492Advanced Settings . . . . . . . . . . . . 493

18.5 The Video Menu . . . . . . . . . . . . . 493


IntroductionGIMP stands for GNU Image Manipulation Pro-gram, and it is one of the most successful appli-cations in the world of free software. The nameGNU is a recursive acronym: GNUs Not Unix,coined in 1983 by the celebrated Richard M.Stallman as a name for his pet projecta freesoftware, Unix-like operating system.

Free software is a term used to describe soft-ware that can be used, studied, modified, andredistributed by anyone with only one, very rea-sonable restriction: that other users enjoy thesame freedom to use the software and to exam-ine and modify the softwares code. Free soft-ware is generally available without charge, butsometimes there is a fee.

The word free must be understood as in freespeech rather than free beer. The termsoftware libre is gaining some popularity, as itnegates this ambiguity. The French word libremeans free in the sense of liberty, whereas theword gratuitmeans free of charge.

GIMP is freely distributed to (and by) any-body, and anybody can look at its contents andits source code and can add features or fix prob-lems. The only restriction is that, if you makeany change to GIMP and want to redistributeit to other people, you must do it in a way thatgrants the recipients exactly the same freedomthat you enjoyed.

GIMP began in 1995 as the school projectof two university students; now GIMP is a full-fledged application, available on all distribu-tions of GNU/Linux and on recent versions of

Microsoft Windows and Mac OS X. InstallingGIMP is fairly easy, and if you havent alreadydone so, take a minute and install GIMP now(see Appendix E for installation instructions).

Compared to the dominant commercialimage-manipulation application, which is de-veloped by an army of well-paid programmers,GIMP is currently developed by a very smallteam of unpaid, but enthusiastic, volunteer pro-grammers. Keep this in mind if (read: when)you run into glitches in the program or whena feature youd like to have isnt available. Re-member the GIMP credo: If you want it sobadly, make it, and share it with the rest of us!Welcome to the world of free software!

This Book

When the idea for this book began to take formin the beginning of 2006, we imagined finishingit in 2010 and covering GIMP 3.0. The firstgoal was nearly met for the French editionthatwas under our controlbut GIMP 3.0 is still faroff because volunteer developers can work onlywhen they have time to do so. Still, GIMP 2.8 isa great leap forward compared to the previousversion, GIMP 2.6. Some of the most note-worthy new features include a single-windowinterface; completely revised and more power-ful brush dynamics; clarification of saving versusexporting images; improved handling of dock-able dialogs; support for layer groups; the abilityto lock pixels, channels, and paths; an improved

xiv Contents in Detail

Hiding or Revealing Parts of theImage Window . . . . . . . . . 575

Padding Colors and Snapping . . . . 57622.4 Building New Brushes . . . . . . . . . . 576

Defining an Ordinary Brush . . . . . . 577Defining a Color Brush . . . . . . . . . 577Defining an Animated Brush . . . . . 577Defining a Parametric Brush . . . . . 579

22.5 Building New Patterns . . . . . . . . . 58022.6 Building New Gradients . . . . . . . . 581

The Gradient Editor . . . . . . . . . . . 581The Gradient Editor Menu . . . . . . . 582Building a Gradient . . . . . . . . . . . 584

22.7 Building New Palettes . . . . . . . . . . 585The Palette Editor . . . . . . . . . . . . . 586Importing Palettes . . . . . . . . . . . . 586Exporting and Duplicating Palettes . 587Palette to Gradient and Sort Palette . 587Indexed Palettes . . . . . . . . . . . . . . 588

Part III AppendicesA Vision and Image

Representation . . . . . . . . . . . . . . 591

A.1 The Physiology of Vision . . . . . . . . 591How the Human Eye Works . . . . . . 591Color Perception . . . . . . . . . . . . . 592Color Blindness . . . . . . . . . . . . . . 593Optical Illusions . . . . . . . . . . . . . . 595

A.2 Image Representation . . . . . . . . . . 597Discretization . . . . . . . . . . . . . . . 597Digitalization . . . . . . . . . . . . . . . 598Compression . . . . . . . . . . . . . . . . 600

A.3 Color Representation . . . . . . . . . . 602How Colors Are Produced . . . . . . . 602The Additive Model . . . . . . . . . . . 604The Subtractive Model . . . . . . . . . 606The HSV Model . . . . . . . . . . . . . . 607

A.4 Exercises . . . . . . . . . . . . . . . . . . 608

B Tips and Hints for SelectedExercises . . . . . . . . . . . . . . . . . . . 609

C Resources . . . . . . . . . . . . . . . . . . 613

C.1 Official GIMP Pages . . . . . . . . . . . 613C.2 Related Official Sites . . . . . . . . . . 614

C.3 Tutorials . . . . . . . . . . . . . . . . . . . 614C.4 Communities and Blogs . . . . . . . . . 615C.5 Brushes and Plug-ins . . . . . . . . . . 615

Brush Sets . . . . . . . . . . . . . . . . . . 616Plug-in Sets . . . . . . . . . . . . . . . . . 616

C.6 Mailing Lists and IRC Channels . . . . 616C.7 Other Graphics Applications . . . . . 616C.8 Related Graphics Software Projects . 617C.9 Other Graphics Sites . . . . . . . . . . 617

D Frequently Asked Questions . . . 619D.1 What Does the Future Hold? . . . . . 619D.2 How...? . . . . . . . . . . . . . . . . . . . 620D.3 Why...? . . . . . . . . . . . . . . . . . . . 622

E Installing GIMP . . . . . . . . . . . . . . 625E.1 GNU/Linux and Unix . . . . . . . . . . 625

Debian . . . . . . . . . . . . . . . . . . . 625Ubuntu . . . . . . . . . . . . . . . . . . . . 626Mint . . . . . . . . . . . . . . . . . . . . . 626Fedora . . . . . . . . . . . . . . . . . . . . 626OpenSUSE . . . . . . . . . . . . . . . . . 626Mandriva . . . . . . . . . . . . . . . . . . 626Other Unix-like Operating Systems . 626

E.2 Windows . . . . . . . . . . . . . . . . . . 627E.3 Mac OS X . . . . . . . . . . . . . . . . . 627

F Batch Processing . . . . . . . . . . . . 629F.1 GIMP Batch Mode . . . . . . . . . . . . 629F.2 Davids Batch Processor . . . . . . . . 630F.3 ImageMagick . . . . . . . . . . . . . . . 632

Calling ImageMagick . . . . . . . . . . 632Building Thumbnails . . . . . . . . . . . 633Labels and Transformations . . . . . . 634

Index . . . . . . . . . . . . . . . . . . . . . . . . . 635


Introduction 0 xvii

after that. In the end, Karine wrote Chapters 3and 8, and Olivier wrote the rest. Karine gavebirth to a healthy, happy girl named Lina, andone year later she gave birth to a second babygirl, Sophie.

Karine is a freelance consultant in web de-velopment and lives in Mrignac, near Bor-deaux, France. She has a masters degree incomputer science, with a specialization in im-age and sound, and she has collaborated on theGIMP development project in various ways.

Olivier is a professor emeritus in computerscience at the University of Nice, France. He hasa doctorate and a Thse dtat in computer sci-ence. He has been a professor at the Universitiesof Grenoble, Montral, Lausanne, and Nice andhas taught many aspects of computer science, in-cluding algorithmics, programming, data struc-tures, compiling, programming language funda-mentals, and graphics processing. He lives inGrasse, a lovely town in the hills of the FrenchRiviera, and several of the photographs used asexamples in this book were taken from his houseor in his garden.

Production Notes

This book was typeset using LATEX, the document-preparation system developed by Leslie Lam-port and based on the TEX typesetting systemdeveloped by Donald Knuth. Olivier wrote aspecialized LATEX class for this book.

All the figures used in Chapters 3 and 8 werecreated by Karine. All the figures used in theother chapters were created by Olivier, unless acopyright designation indicates otherwise. Ap-propriate authorizations were obtained fromthe people whose photographs were used in thisbook.

Most screen shots were created on computersrunning the Debian distribution of GNU/Linuxwith the Glossy preference theme. You may seeminor differences in the appearance of windowson systems running other distributions or op-

erating systems or using different preferencethemes.

ConventionsGIMP was used to crop the window decorationout of most screen shots to save space and high-light the relevant information.

The notation Image: Colors > Curves meansthat you should click the Colors menu in thewindow of the image you are working on andthen click the entry called Curves. This typeof notation can include more menu levels, ofcourse. Similarly, Layers: right-click > Add anAlpha channelmeans that you should right-clickin the Layers dialog and choose Add an Alphachannel from the menu that appears.

The notation U means you should press thecorresponding key on the keyboard. CTRL+Umeans that you press and hold the Control keyand then press the U key.

Small caps, as in FEATHER, are used to denotethe name of an entry, a button, or a checkbox.

A monospace font like Abstract 1 is used todenote specific text that the user must type intoan input field.

AcknowledgmentsFrom the beginning, we wanted this book to befull color. We considered it a shame that mostbooks published about GIMP contained colorprints in a middle section onlyor no color atall. We are very grateful to both our publishersfor having agreed to print in full color, despitethe additional costs.

Our debt to the GIMP developers is immense:The work they did and are still doing is tremen-dous. Moreover, we had the opportunity toask them some questions, using the gimp-userand gimp-developer mailing lists and the #gimpIRC channel. They graciously responded to ourquestions with invaluable first-hand informationabout difficult aspects of GIMP. Wed especially

xvi Introduction

Free Select tool; support for selecting and tag-ging multiple objects in resource lists (brushes,gradients, and palettes); a new Text tool withon-canvas editing capabilities; a large set of newbrushes, brush dynamics, and tool presets; andmany other features that make the program eas-ier and more enjoyable to use. GIMP still lacksnondestructive editing, CMYK native support,and 16-bit depth color handling. Some of thesefeatures will likely appear in the next version,with support from the Generic Graphic Library(GEGL).

This book aims to fulfill two different pur-poses: to provide hands-on, task-oriented GIMPtutorials and to provide a comprehensive ref-erence manual. Because these two goals aredistinct, we designed the book in two parts. Inthe first part, eight independent chapters willwalk you through the main tasks you can per-form using GIMP. Each chapter begins with ahands-on tutorial and ends with exercises thatreinforce the concepts covered.

You might want to start with Appendix A,which explains the theory behind image repre-sentation, and Chapter 1, which helps you tostart using GIMP, but you can read the otherchapters in any order. For example, if you aremainly interested in photo manipulation, readChapters 2 and 5. If you are more interested ingraphic design, read Chapters 3 and 4. And ifyou read all the tutorial chapters in order, youllhave a solid grasp of most aspects of GIMP.

The final 14 chapters constitute a thoroughGIMP reference manual. We tried to cover allaspects in a logical order, using as many exam-ples and illustrations as possible. We also triedto avoid explaining the same thing several times.Of course, topics overlap between the two parts,but we tried to keep repetition to a minimumand, when it was unavoidable, to explain thingsin a new way.

The chapters in the second part are arrangedin a logical order, but, because this part is in-tended as a reference manual, you certainly donot need to read the chapters in order. Weve

included cross-references to help you find whatyou need to move your project forward. Someof the chapters in the second part corresponddirectly with a chapter from the first part. Inthose cases, we recommend that you first readthe tutorial chapter and then refer to the rele-vant chapter(s) in the second part of the book.These paired chapters include 3 and 15, and 6and 18. Additionally, Chapters 9 to 14 presentsome basic concepts that are used regularly inlater chapters.

We used a bleeding-edge, developmental ver-sion of GIMP to ensure that everything wasup-to-date as of the books completion, andweve covered every aspect of GIMP as thor-oughly as possible, with the exception of thetools in the second half of the Image: Createmenu and those in the Image: Filters > Alpha tologo menu. We chose not to cover those toolsbecause theyre self-explanatory and have only afew parameters.

We struggled with the decision of whether tocover the many plug-ins and scripts that usershave added to GIMP. Many of them would re-quire an entire long chapter of their own. Wedecided to cover only one addition, the plug-inset called GIMP Animation Package (GAP), be-cause it adds a powerful capability that GIMPalone lacks. In Chapter 21, we mention a few ad-ditional plug-ins to give readers an idea of whatsavailable.

The Authors

Karine Delvare contributed to this book projectfrom the beginning. The concept, as well as theorganization and early drafts of the chapters,were created by both authors. But after pub-lishers were found (one for the French editionand one for the English edition) and the editingprocess began, Karine became pregnant anddecided that motherhood was her first prior-ity. Olivier offered her his full support and tookover themajority of book-related responsibilities


Introduction 0 xvii

after that. In the end, Karine wrote Chapters 3and 8, and Olivier wrote the rest. Karine gavebirth to a healthy, happy girl named Lina, andone year later she gave birth to a second babygirl, Sophie.

Karine is a freelance consultant in web de-velopment and lives in Mrignac, near Bor-deaux, France. She has a masters degree incomputer science, with a specialization in im-age and sound, and she has collaborated on theGIMP development project in various ways.

Olivier is a professor emeritus in computerscience at the University of Nice, France. He hasa doctorate and a Thse dtat in computer sci-ence. He has been a professor at the Universitiesof Grenoble, Montral, Lausanne, and Nice andhas taught many aspects of computer science, in-cluding algorithmics, programming, data struc-tures, compiling, programming language funda-mentals, and graphics processing. He lives inGrasse, a lovely town in the hills of the FrenchRiviera, and several of the photographs used asexamples in this book were taken from his houseor in his garden.

Production Notes

This book was typeset using LATEX, the document-preparation system developed by Leslie Lam-port and based on the TEX typesetting systemdeveloped by Donald Knuth. Olivier wrote aspecialized LATEX class for this book.

All the figures used in Chapters 3 and 8 werecreated by Karine. All the figures used in theother chapters were created by Olivier, unless acopyright designation indicates otherwise. Ap-propriate authorizations were obtained fromthe people whose photographs were used in thisbook.

Most screen shots were created on computersrunning the Debian distribution of GNU/Linuxwith the Glossy preference theme. You may seeminor differences in the appearance of windowson systems running other distributions or op-

erating systems or using different preferencethemes.

ConventionsGIMP was used to crop the window decorationout of most screen shots to save space and high-light the relevant information.

The notation Image: Colors > Curves meansthat you should click the Colors menu in thewindow of the image you are working on andthen click the entry called Curves. This typeof notation can include more menu levels, ofcourse. Similarly, Layers: right-click > Add anAlpha channelmeans that you should right-clickin the Layers dialog and choose Add an Alphachannel from the menu that appears.

The notation U means you should press thecorresponding key on the keyboard. CTRL+Umeans that you press and hold the Control keyand then press the U key.

Small caps, as in FEATHER, are used to denotethe name of an entry, a button, or a checkbox.

A monospace font like Abstract 1 is used todenote specific text that the user must type intoan input field.

AcknowledgmentsFrom the beginning, we wanted this book to befull color. We considered it a shame that mostbooks published about GIMP contained colorprints in a middle section onlyor no color atall. We are very grateful to both our publishersfor having agreed to print in full color, despitethe additional costs.

Our debt to the GIMP developers is immense:The work they did and are still doing is tremen-dous. Moreover, we had the opportunity toask them some questions, using the gimp-userand gimp-developer mailing lists and the #gimpIRC channel. They graciously responded to ourquestions with invaluable first-hand informationabout difficult aspects of GIMP. Wed especially

xvi Introduction

Free Select tool; support for selecting and tag-ging multiple objects in resource lists (brushes,gradients, and palettes); a new Text tool withon-canvas editing capabilities; a large set of newbrushes, brush dynamics, and tool presets; andmany other features that make the program eas-ier and more enjoyable to use. GIMP still lacksnondestructive editing, CMYK native support,and 16-bit depth color handling. Some of thesefeatures will likely appear in the next version,with support from the Generic Graphic Library(GEGL).

This book aims to fulfill two different pur-poses: to provide hands-on, task-oriented GIMPtutorials and to provide a comprehensive ref-erence manual. Because these two goals aredistinct, we designed the book in two parts. Inthe first part, eight independent chapters willwalk you through the main tasks you can per-form using GIMP. Each chapter begins with ahands-on tutorial and ends with exercises thatreinforce the concepts covered.

You might want to start with Appendix A,which explains the theory behind image repre-sentation, and Chapter 1,

Documents

The Book of GIMP - A Complete Guide to Nearly Everything