Joshua Pruitt and Ramona Pruitt

Teach Yourself

GIMP

in24Hours

A Division of Macmillan Computer Publishing 201 West 103rd Street, Indianapolis, Indiana 46290

Sams Teach Yourself GIMP in

24 Hours

Copyright © 1999 by Sams Publishing

All rights reserved. No part of this book shall be reproduced, stored in a retrieval system, or transmitted by any means, electronic, mechanical, photocopying, recording, or otherwise, without written permission from the publisher. No patent liability is assumed with respect to the use of the information contained herein. Although every precaution has been taken in the preparation of this book, the publisher and authors assume no responsibility for errors or omissions. Neither is any liability assumed for damages resulting from the use of the information contained herein.

International Standard Book Number: 0-672-31509-2

Library of Congress Catalog Card Number: 98-87919

Printed in the United States of America

First Printing: March 1999

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Trademarks

All terms mentioned in this book that are known to be trademarks or service marks have been appropriately capitalized. Sams cannot attest to the accuracy of this information. Use of a term in this book should not be regarded as affecting the validity of any trademark or service mark.

Warning and Disclaimer

Every effort has been made to make this book as complete and as accurate as possible, but no warranty or fitness is implied. The information provided is on an as is basis. The authors and the publisher shall have neither liability or responsibility to any person or entity with respect to any loss or damages arising from the information contained in this book or from the use of the CDROM or programs accompanying it.

EXECUTIVE EDITOR

Brad Koch

ACQUISITIONS EDITOR

Dustin Sullivan

DEVELOPMENT EDITOR

Tom Dinse

MANAGING EDITOR

Brice Gosnell

PROJECT EDITOR

Gretchen Uphoff

COPY EDITOR

Pamela Woolf

INDEXER

Bruce Clingaman

PROOFREADER

Billy Fields

TECHNICAL EDITOR

Zach Beane

SOFTWARE DEVELOPMENT

SPECIALIST

Jack Belbot

INTERIOR DESIGN

Gary Adair

COVER DESIGN

Aren Howell

LAYOUT TECHNICIANS

Branden Allen

Stacey DeRome

Timothy Osborn

Staci Somers

Contents at a Glance

	Introduction	1
Hour 1	Installation and Configuration	5
2	Getting Started	17
3	Basic GIMP Tools	31
4	Using Brushes and Patterns in Depth	43
5	Working with Selections	55
6	Transformations	73
7	Working with Color	85
8	Introduction to Layers	107
9	Hands-on Layering	121
10	Using Masks	133
11	Special Effects	145
12	Using Filters to Improve or Distort Images	159
13	Artistic Filters	171
14	Cool Text Effects	189
15	Web Graphics	201
16	Photo Compositing	215
17	Photo Restoration and Enhancement	229
18	Digital Painting	241
19	About Plug-ins	253
20	Using More Plug-ins and Extensions	261
21	What the Heck Is Script-Fu	279
22	More with Script-Fu	293
23	Animations	301
24	Using Peripherals with Linux	311
	Index	319

Contents
INTRODUCTION	1
HOUR 1 INSTALLATION AND CONFIGURATION	5
Bring Out the GIMP ................................................................................................	5
Installing Linux—A Primer ....................................................................................	6
System Requirements for Running GIMP ..............................................................	8
About GTK ........................................................................................................	8
Graphics Libraries ..............................................................................................	9
Other Things ......................................................................................................	9
Installing GIMP ....................................................................................................	10
Binary Installation ............................................................................................	10
Source Installation ............................................................................................	12
Summary ................................................................................................................	15
Q&A ......................................................................................................................	16
Exercise ............................................................................................................	16
HOUR 2 GETTING STARTED	17
Your First GIMP Session ......................................................................................	17
The GIMP Interface ..............................................................................................	20
Creating a New File ..............................................................................................	20
File Size ............................................................................................................	21
Image Type ......................................................................................................	21
Fill Type............................................................................................................	21
Opening Files ........................................................................................................	21
File Formats ..........................................................................................................	22
Closing and Saving Files ......................................................................................	25
Other Toolbox Menu Options ................................................................................	26
About ................................................................................................................	26
Tip of the Day ..................................................................................................	27
Dialogs..............................................................................................................	27
Preferences........................................................................................................	27
The Xtns Menu ......................................................................................................	27
Exiting the GIMP ..................................................................................................	28
Summary ................................................................................................................	28
Q&A ......................................................................................................................	28
Exercise..................................................................................................................	29

Contents

v

HOUR 3 BASIC GIMP TOOLS	31
Using the Basic Tools ............................................................................................	31
Selection Tools ................................................................................................	32
Transformation Tools........................................................................................	33
Artistic Tools ....................................................................................................	34
The Color Tools ................................................................................................	35
Text Tool ..........................................................................................................	38
Summary ................................................................................................................	41
Q&A ......................................................................................................................	42
Exercise..................................................................................................................	42
HOUR 4 USING BRUSHES AND PATTERNS IN DEPTH	43
Using Brushes ........................................................................................................	44
The Brush Settings ..........................................................................................	44
Tool Options ....................................................................................................	45
Making Custom Brushes ..................................................................................	47
Using Patterns ........................................................................................................	49
The Pattern Dialog............................................................................................	49
Using the Fill Tool with Patterns ....................................................................	50
Custom Patterns................................................................................................	50
Seamless Tiling ................................................................................................	51
Saving Patterns ................................................................................................	52
Summary ................................................................................................................	53
Q&A ......................................................................................................................	53
Exercise..................................................................................................................	53
HOUR 5 WORKING WITH SELECTIONS	55
The Selection Tool Icons ......................................................................................	56
Tool Options ..........................................................................................................	56
Setting the Basic Options ................................................................................	56
Viewing a Selection ..............................................................................................	58
Making a Selection ................................................................................................	58
Extra Selections ................................................................................................	59
Adding to a Selection ......................................................................................	59
Subtracting from a Selection ............................................................................	60
Intersecting the Selections................................................................................	60
Deactivating a Selection ..................................................................................	61
Shape Tool Extras ..................................................................................................	61
Lasso Selections ....................................................................................................	62
Fuzzy Select ..........................................................................................................	62

vi	Sams Teach Yourself GIMP in 24 Hours

The Bézier Tool ....................................................................................................	63
Setting as a Selection........................................................................................	64
Putting the Bézier to Work ..............................................................................	65
Intelligent Scissors ................................................................................................	66
Intelligent Scissors Options..............................................................................	67
The Selection Menu Options ................................................................................	68
Toggle ..............................................................................................................	68
Invert ................................................................................................................	68
All ....................................................................................................................	68
None..................................................................................................................	68
Float ..................................................................................................................	68
Feather ..............................................................................................................	69
Sharpen ............................................................................................................	69
Border ..............................................................................................................	69
Grow and Shrink ..............................................................................................	69
Save to Channel................................................................................................	69
Select by Color ................................................................................................	69
The Stroke..............................................................................................................	69
Using Guides with Selections................................................................................	70
Editing Selections ..................................................................................................	71
Moving a Selection ..........................................................................................	71
Copying and Pasting Selections ......................................................................	71
Summary ................................................................................................................	72
Q&A ......................................................................................................................	72
Exercise..................................................................................................................	72
HOUR 6 TRANSFORMATIONS	73
Transformation Tools ............................................................................................	74
Move ................................................................................................................	74
Magnify ............................................................................................................	75
Crop........................................................................................................................	76
Transform ..............................................................................................................	77
Rotation ............................................................................................................	77
Scaling ..............................................................................................................	78
Shearing ............................................................................................................	80
Perspective........................................................................................................	80
Flip....................................................................................................................	81
Tutorial ..................................................................................................................	81
Summary ................................................................................................................	84
Q&A ......................................................................................................................	84
Exercise..................................................................................................................	84

Contents

vii

HOUR 7 WORKING WITH COLOR	85
The GIMP and Color ............................................................................................	86
Color Models ........................................................................................................	86
RGB Model ......................................................................................................	86
HSV Model ......................................................................................................	87
Indexed Model..................................................................................................	88
Grayscale ..........................................................................................................	89
CMYK Model ..................................................................................................	89
Color Channels ......................................................................................................	90
Working with Transparencies ................................................................................	91
Other Color Options ..............................................................................................	94
Equalize ............................................................................................................	94
Posterize............................................................................................................	95
Threshold ..........................................................................................................	95
Color Balance ..................................................................................................	95
Brightness/Contrast ..........................................................................................	96
Hue/Saturation ..................................................................................................	96
Curves ..............................................................................................................	97
Levels................................................................................................................	98
A Few Others....................................................................................................	98
Gradients ................................................................................................................	99
Gradient Editor ....................................................................................................	103
Summary ..............................................................................................................	104
Q&A ....................................................................................................................	105
Exercise................................................................................................................	105
HOUR 8 INTRODUCTION TO LAYERS	107
What Are Layers? ................................................................................................	108
The Layer Dialog Box....................................................................................	108
Adding and Deleting Layers ..........................................................................	109
Selecting and Moving Layers ........................................................................	110
The Layer Dialog Menu ................................................................................	111
Aligning Layers ..............................................................................................	113
Tutorials ..........................................................................................................	113
Summary ..............................................................................................................	119
Q&A ....................................................................................................................	119
Exercise ................................................................................................................	119
HOUR 9 HANDS-ON LAYERING	121
Blend Modes ........................................................................................................	121
Blend Modes Quick Reference Guide............................................................	122
Examples ........................................................................................................	123

viii	Sams Teach Yourself GIMP in 24 Hours

Tutorials ..............................................................................................................	127
Working with Color........................................................................................	127
Working with Black and White ......................................................................	129
Blending Images ............................................................................................	130
Summary ..............................................................................................................	131
Q&A ....................................................................................................................	131
Exercise................................................................................................................	132
HOUR 10 USING MASKS	133
What Are Masks? ................................................................................................	134
Creating Masks ..............................................................................................	134
Viewing the Mask ..........................................................................................	137
Applying the Mask ........................................................................................	137
Masks with Selections and Channels ............................................................	137
Mask Tutorials ....................................................................................................	138
Gradient Masks ..............................................................................................	138
Photo Edge Masks ..........................................................................................	139
Text Mask ......................................................................................................	142
Summary ..............................................................................................................	143
Q&A ....................................................................................................................	143
Exercise................................................................................................................	144
HOUR 11 SPECIAL EFFECTS	145
Tips and Tricks ....................................................................................................	145
Creating Sharp Images from Scratch ..................................................................	146
Simple and Complex Shapes..........................................................................	146
Drop Shadows and Glows ..............................................................................	148
Imitating Real Objects in 3D..........................................................................	150
Stained Glass Effect ......................................................................................	155
Summary ..............................................................................................................	158
Q&A ....................................................................................................................	158
Exercise................................................................................................................	158
HOUR 12 USING FILTERS TO IMPROVE OR DISTORT IMAGES	159
What Exactly Are Filters?....................................................................................	159
Using Filters ........................................................................................................	160
Filters that Come with the GIMP ........................................................................	160
Blur and Sharpen Filters ......................................................................................	161
Blur 2.0 ..........................................................................................................	161
Gaussian Blur ................................................................................................	162
Pixelize ..........................................................................................................	162
Motion Blur ....................................................................................................	163

Contents

ix

Enhancing Your Images ......................................................................................	164
Sharpen ..........................................................................................................	165
Despeckle........................................................................................................	165
NL Filter ........................................................................................................	166
Destripe ..........................................................................................................	167
Noise Filters ........................................................................................................	167
Noisify ............................................................................................................	167
Randomize ......................................................................................................	167
Spread ............................................................................................................	168
Obtaining Filters ..................................................................................................	169
Summary ..............................................................................................................	170
Q&A ....................................................................................................................	170
Exercise................................................................................................................	170
HOUR 13 ARTISTIC FILTERS	171
Using Filters Artistically......................................................................................	171
GIMPressionist ..............................................................................................	172
IWarp ..............................................................................................................	178
Cubism............................................................................................................	180
Mosaic ............................................................................................................	180
Whirl and Pinch..............................................................................................	181
Waves..............................................................................................................	181
Apply Canvas and Apply Carpet....................................................................	182
Light Effects ..................................................................................................	182
Miscellaneous Effects ....................................................................................	184
Alien Map ......................................................................................................	184
User Filters ....................................................................................................	184
Summary ..............................................................................................................	186
Q&A ....................................................................................................................	187
Exercise................................................................................................................	187
HOUR 14 COOL TEXT EFFECTS	189
Working with the Text Tool ................................................................................	190
Dazzling Text Effects from Scratch ....................................................................	190
Beveled Text ..................................................................................................	190
Metallic Text ..................................................................................................	194
Cutout Text ....................................................................................................	196
Easy Emboss ..................................................................................................	197
Summary ..............................................................................................................	198
Q&A ....................................................................................................................	198
Exercise................................................................................................................	199

x	Sams Teach Yourself GIMP in 24 Hours

HOUR 15 WEB GRAPHICS		201
	File Size ..............................................................................................................	201
	File Formats ........................................................................................................	202
	JPEG ..............................................................................................................	202
	GIF..................................................................................................................	202
	Web-Safe Palettes—Necessary or Outdated? ......................................................	203
	Making Good Looking Web Sites Quickly and Effectively................................	205
	Backgrounds ..................................................................................................	205
	Buttons, Bars, and Bullets ..............................................................................	209
	Consoles..........................................................................................................	211
	Summary ..............................................................................................................	213
	Q&A ....................................................................................................................	213
	Exercise................................................................................................................	213
HOUR 16	PHOTO COMPOSITING	215
	What Is a Composite?..........................................................................................	215
	Creating Composites............................................................................................	216
	Using Selections in Composites ....................................................................	216
	Using Feathering ............................................................................................	218
	Opacity............................................................................................................	220
	Blend Modes ..................................................................................................	221
	Gradients ........................................................................................................	222
	Framing Photos ....................................................................................................	224
	Summary ..............................................................................................................	227
	Q&A ....................................................................................................................	227
	Exercise................................................................................................................	228
HOUR 17 PHOTO RESTORATION AND ENHANCEMENT		229
	“This Photo Looks Bad! Is It Salvageable?” ......................................................	230
	Tips and Tricks for Working with Old Photos ..............................................	230
	Removing Flaws ............................................................................................	230
	Color Manipulation ........................................................................................	234
	Edge Effects ........................................................................................................	238
	Summary ..............................................................................................................	239
	Q&A ....................................................................................................................	240
	Exercise................................................................................................................	240
HOUR 18	DIGITAL PAINTING	241
	Simulating Painting..............................................................................................	242
	Lesson 1—Watercolor ....................................................................................	242
	Lesson 2—Landscape ....................................................................................	244
	Lesson 3—Spacescape ..................................................................................	248

Contents

xi

Summary ..............................................................................................................	251
Q&A ....................................................................................................................	252
Exercise................................................................................................................	252
HOUR 19 ABOUT PLUG-INS	253
So, What Exactly Are Plug-ins? ..........................................................................	253
How to Obtain and Install New Plug-ins ............................................................	255
Why Compile?................................................................................................	255
Installing the Easy Way ..................................................................................	256
./configure && make && make install......................................................	256
The DB Browser ..................................................................................................	257
Summary ..............................................................................................................	258
Q&A ....................................................................................................................	258
Exercise................................................................................................................	259
HOUR 20 USING MORE PLUG-INS AND EXTENSIONS	261
Gfig ......................................................................................................................	262
GUASH................................................................................................................	266
IfsCompose ..........................................................................................................	267
Fractal Explorer ..................................................................................................	271
Screen Shot ..........................................................................................................	274
Inroot....................................................................................................................	274
Crypto Tools ........................................................................................................	275
Encrypt/Decrypt..............................................................................................	275
Stegano ..........................................................................................................	276
Summary ..............................................................................................................	277
Q&A ....................................................................................................................	277
Exercise................................................................................................................	277
HOUR 21 WHAT THE HECK IS SCRIPT-FU?	279
Using Script-Fu....................................................................................................	280
Script-Fu Examples ........................................................................................	280
Summary ..............................................................................................................	290
Q&A ....................................................................................................................	290
Exercise................................................................................................................	291
HOUR 22 MORE WITH SCRIPT-FU	293
Using Script-Fu in Combination with Your Own Effects ..................................	293
Dissecting the Image ......................................................................................	294
Script-Fu as a Tool ..............................................................................................	295
Brushes Revisited ..........................................................................................	295
Rounded Selections ........................................................................................	295
Script-Fu—A Look Ahead ..................................................................................	297

xii	Sams Teach Yourself GIMP in 24 Hours

Procedural Database ............................................................................................	298
Net-Fu ..................................................................................................................	298
Summary ..............................................................................................................	299
Q&A ....................................................................................................................	299
Exercise................................................................................................................	299
HOUR 23 ANIMATIONS	301
Creating a Simple Animation ..............................................................................	302
Building Animations for the Web ........................................................................	305
A Word About GIF89a ..................................................................................	305
Size Issues............................................................................................................	306
Optimizing Animations........................................................................................	307
Summary ..............................................................................................................	309
Q&A ....................................................................................................................	310
Exercise................................................................................................................	310
HOUR 24 USING PERIPHERALS WITH LINUX	311
Digital Scanners ..................................................................................................	311
Digital Cameras ..................................................................................................	314
Color Printers ......................................................................................................	314
Wacom Pens and Other Pointing Devices ..........................................................	316
A Word About Video Editing ..............................................................................	317
Summary ..............................................................................................................	317
Q&A ....................................................................................................................	318
Exercise................................................................................................................	318
INDEX	319