Drawing in gimp
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Drawing in GIMP. GIMP User Manual. Lesson Overview. Understand how new graphical content can created by combining free-hand techniques with existing image content Become familiar with some common graphics terminology: dithering, anti-aliasing, haloing, color modes, and alpha transparency

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Drawing in GIMP

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Drawing in gimp

Drawing in GIMP

GIMP User Manual

Lesson overview

Lesson Overview

  • Understand how new graphical content can created by combining free-hand techniques with existing image content

  • Become familiar with some common graphics terminology: dithering, anti-aliasing, haloing, color modes, and alpha transparency

  • Learn how to use the basic drawing tools and options of a graphical application like GIMP

  • Extend the capability of GIMP to create vector like shapes using the Gfig dialog

Some drawing terminology

Some Drawing Terminology

  • Dithering

  • Anti-aliasing

  • Haloing

  • Color Modes

  • Alpha Transparency



  • Dithering is a technique used in computer graphics to create the illusion of more colors when displaying an image which has a low color depth

  • The missing colors are reproduced by a certain arrangement of pixels in the available colors

    • The human eye perceives this as a mixture of the individual colors

  • Dithering increases the size of an indexed formatted image

  • The Gradient Tool in GIMP uses dithering

Dithering and indexed format

Dithering and Indexed Format

  • When converting a GIMP image from RGB format to Indexed Format you may choose dithering to smooth banding effects

  • Both GIF and PNG formats can use indexed color

Anti aliasing


  • When rendering an edge at an angle, it will look “jagged” because of the nature of pixels

  • Anti-aliasing tries to make the edges look smoother by giving the boundary pixels a color between the image and the background image

  • The human eye then blends the two colors on either side

  • Good for text in graphics

  • Adds to the file size



  • Haloing is undesirable effect that is created when using transparency

  • Caused because the edges of an anti-aliased object, such as text, are not purely the background color, they have been blurred

  • When the background is made transparent, these blurred pixels still show up

Preventing haloing

Preventing Haloing

  • If possible, set background color to your planned web page background color

  • If you want transparency in the background, set this before drawing any shapes or text

  • You can also turn off anti-aliasing for a drawing tool or selection tool

Color modes in gimp

Color Modes in GIMP

  • True Color (RGB)

    • Millions of colors

  • Grayscale

    • The grayscale mode uses one channel to display a gray image

  • Indexed Color

    • The image consist of pixels picked from a palette of up to 256 colors

    • By converting to this mode you are reducing the color depth of an image

Color mode menus

Color Mode Menus

  • Menu items for color modes:

    • Image > Mode > RGB

    • Image > Mode > Grayscale

    • Image > Mode > Indexed

Alpha transparency

Alpha Transparency

  • Regardless of the mode, images can have an optional alpha channel for transparency

  • By enabled by alpha channel, you can create a picture by stacking several layers on top of each other, save images for the web, or create images for 3D graphics that have holes or semi-opaque areas

  • Use GIF as a Web format to supports fully opaque or fully transparent images

Alpha transparency menus

Alpha Transparency Menus

  • Menu items for alpha channel:

    • Layer > Transparency > Add Alpha Channel

    • Layer > Transparency > Remove Alpha Channel

    • Layer > Transparency > Add to Selection

Drawing in gimp1

Drawing in GIMP

  • Most drawings begin with a blank canvas

  • Choose the image size and background color

  • Always create a layer for each figure in your drawing

    • This allows you to duplicate figures and change background color if necessary

    • Name each layer for the main figure on the layer

Drawing techniques in gimp

Drawing Techniques in GIMP

  • Drawing lines and curves

  • Changing colors and brushes

  • Drawing circles, rectangles, and other shapes

    • Using a filter to draw temporary vector graphical objects

  • Outlining and filling regions

  • Filling with patterns and gradients

New image

New Image

  • Always start with an existing or a new image

  • Set the background color or make it transparent

  • Create a new layer for each functional unit of your drawing

  • Name the layer with a meaningful name

Drawing lines and curves

Drawing Lines and Curves

  • Use the Pencil tool to create hard-edged lines

  • To draw a free hand line, hold down the left mouse button and drag the mouse where you want.

  • To draw a straight line, click the first point, hold down the shift key, then click the last point.

  • The pencil will have a round point determined by the brush that is selected

    • To turn off the brush size in the cursor, go to Edit=>Preferences=>Image Window and set Mouse Pointer Pointer Mode to be Tool Icon with crosshair or just crosshair

Pencil line drawing

Pencil Line Drawing



  • Changing the brush gives you control of the width and shape of the lines you draw with any of the GIMP drawing tools

  • There are several ways to change brushes

    • Click on the brush circle in the toolbox brush icon or choose to show the brushes panel from the Windows=>Dockable Dialogs=>Brushes menu

Change brushes

Change Brushes

  • Changing a brush type is easy

  • Just click on the brush icon to bring up the Brushes Panel

Click to View

Brushes panel

Brushes Panel

  • There are many types of brushes to choose from

  • Just click to choose a different brush

Animated image brushes

Animated Image Brushes

  • Some built in animated image brushes can be selected

  • You can vary the spacing

  • The fixed color ignores current foreground or background colors

Importing abobe brushes

Importing Abobe Brushes

  • There are many brushes available on the Internet

  • One standard format that can be imported into GIMP are Abobe brushes.

    • These are usually available in zipped files

    • The extension are .abr for Adobe brushes

  • Loading too many brushes will make GIMP take a long time to start

Brusheezy com

Brusheezy.com –

  • This web site has many Adobe brushes available with unrestricted use requirements

  • Download the zipped file

  • Extract the .abr files

  • Place in your GIMP brushes area:

    • C:/ProgramFiles/GIMP-2.0/share/gimp//2.0/brushes/

Custom brushes

Custom Brushes

  • Custom brushes you load can be drawn like a line or stamped to create an individual image

  • You can usually size the brush, choose a color, set opacity or other brush attributes

  • Don’t be afraid to experiment with these custom brushes, you can always undo and try again

Image made with adobe brushes

Image made with Adobe Brushes

Parametric brushes

Parametric Brushes

  • Parametric brushes are based on a mathematical representation of a shape like round, diamond, or square

  • Use the Brush Editor dialog to create a new brush with the following:

    • Radius

    • Hardness

    • Aspect Ratio

    • Angle

    • Spacing

Drawing tool options

Drawing Tool Options

  • All the line drawing tools have similar options:

    • Opacity – percentage of transparency

    • Mode – special drawing modes

    • Fade out – line fades over a distance

    • Incremental- only if opacity is < 100%, will make a line darker if repeated

    • Use color from gradient – Uses gradient instead of current foreground color

Pencil drawing options

Pencil Drawing Options

  • Chose to use color from gradient

Special layer drawing modes

Special Layer Drawing Modes

  • Normal

  • Dissolve

  • Behind and Color Erase modes needs a top layer with an alpha channel (transparency)

Fuzzy or smooth lines

Fuzzy or Smooth Lines?

  • The pencil tool draws hard-edged lines but has jagged edges

    • Not anti-aliased by default

  • The paintbrush tool draws fuzzy lines with the brushes

    • These lines are anti-aliased

    • The edges are semi-transparent and are blended with the background color

  • The paintbrush can also use hard-edged brushes

Aliased or anti aliased lines

Aliased or Anti-Aliased Lines



Airbrush tool

Airbrush Tool

  • This tool always draws a fuzzy edge, even if a hard-edged brush is selected

  • The airbrush is time sensitive, the slower you go, the darker it draws

    • The Rate controls how sensitive the tool is to movement

    • The Pressure controls the darkness. Think of this as the amount of paint the airbrush is spraying

The calligraphic brush

The Calligraphic Brush

  • This tool mimics a real calligraphic pen or brush

  • Choose the airbrush tool, then select a calligraphic brush

  • The path of the line changes depending of the orientation of the brush

  • Uses the same options as the airbrush tool, rate and pressure

Ink pen tool

Ink Pen Tool

  • This tool emulates an old fashioned fountain pen

  • Has different shaped nibs or point types

  • Ignores other brushes

  • Has its own notion of a brush

The ink pen tool

The Ink Pen Tool

  • Adjustment controls the width of the nib and its angle

  • Sensitivity controls how much ink is released

  • Type controls shape of nib

  • TheShape box allows dragging of square to change shape

The eraser tool

The Eraser Tool

  • If the current layer has an alpha channel, the layer supports transparency, then the eraser will work

  • The eraser uses the current brush to affect its shape

  • You can zoom to magnify the image to control erasing at the pixel level

  • Can erase with a hard edge or a soft edge

The erase tool

The Erase Tool

Drawing shapes

Drawing Shapes

  • GIMP is not a vector graphic drawing program

  • The Gfig Filter allows some vector graphic shape drawing capability (More later on this!)

  • Use a selection tool and then fill or stroke the selection to make your own shapes

Outlining selections stroking

Outlining Selections: Stroking

  • Draw a selection with either the rectangle, ellipse selection tools

  • Open the Stroke Selection dialog once the selection is active by Edit=>Stroke Selection

  • Set the Line Width, the Line Style or choose a paint tool if wanted

  • Then click the Stoke button

Stroking a selection

Stroking a Selection

  • Rectangle selection

  • Line Width 12

  • Line Style was a wood grain Pattern

Free select with the lasso

Free Select with the Lasso

  • Draw any shape with the Lasso tool

  • You can use the Stoke Selection dialog to stroke the edge of the selected area

  • Use Edit=>Fill with FG Color to fill the selection with the current foreground color

  • You can also fill a selection by dragging the forecolor or background color pattern swatches into the image

Free select tool selection

Free Select Tool Selection

  • Create selection using the Free Select Tool (also called Lasso)

  • Stroke Selection using Paintbrush

  • Fill color using Fill with FC Color

Fuzzy selection tool

Fuzzy Selection Tool

  • Also called the Magic Wand

  • This tool allows selection based on color similarity

  • The Threshold option can be used to broaden the selection to touching pixels

Selection using fuzzy select

Selection using Fuzzy Select

Paths tool

Paths Tool

  • The Paths Tool allows you to create complex selection known as Bezier Curves

  • You can edit your curve, add or delete points

Paths tool example

Paths Tool Example

Bucket fill tool

Bucket Fill Tool

  • Use this tool for more complicated color filling

  • Opacity and Mode are the same as with other tools

  • Fill Type lets you fill with FG, BG, or Pattern

  • Holding <Ctrl> will reverse fill type

Bucket tool affected area

Bucket Tool – Affected Area

  • Check to Fill similar colors

  • The Threshold slides controls just how similar the colors will be

  • This may take some experimenting to get it right



  • A Pattern is just an image

  • Patterns are usually tileable, repeatable

  • Use the Pattern swatch to set the Pattern you want

  • Patterns can be edited and saved as a new Pattern

Adding new patterns

Adding New Patterns

  • Create your own pattern and save it with a .pat extension

  • Find a pattern with a .pat extension such as those at www.Brusheezy.com

  • Place in your pattern file in this area:

    • C:/ProgramFiles/GIMP-2.0/share/gimp//2.0/patterns/

  • Open GIMP again and the pattern should be available



  • The Blend tool is another way to fill areas

  • Set the Opacity or Mode

  • Choose a Gradient

  • Choose a Shape and Offset



  • With the blend tool selected, mouse down in a selection and drag in the direction you want the gradient to flow

Reverse gradient

Reverse Gradient

  • Use a selection tool like the lasso to draw the selection

  • Choose a Gradient and then click the Reverse box

  • Use your mouse to drag the direction you want

Vector graphics with gfig

Vector Graphics with Gfig

  • A special filter called Gfig can be used to create a layer with vector graphics

  • After drawing your shapes, close the Gfig editor and you will now have a layer in your drawing

  • You can save your Gfig drawing and reopen it at another time

  • Go to the Filter=>Render=>Gfig

Vector graphics converted

Vector Graphics Converted

  • After closing the Gfig editor

  • The vector graphics are converted into raster graphics

  • They have their own layer

Modify gfig layer

Modify Gfig Layer

  • The Gfig shapes are now just pixels on a layer

  • They can be selected, transformed and moved



  • Use the various tools and brushes to create the drawing you want

  • Fill the shapes and add stroking to control the edges

  • Use the Gfig filter to draw vector graphic shapes if you need to

  • You can use these techniques to draw anything you can think of, with patience and a lot of layers

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