GIMPGNU Image Manipulation Program

Tutorial

©Meghna Singh

Why GIMP ?

� Its FREE (open source)!

� Has all the capabilities of any other photo-editor, AND MUCH MORE!

� You can write your own filter scripts/editor tools and share with the rest of the world.

�GIMP is known to work on Linux, Windows, OpenBSD, NetBSD, FreeBSD, Solaris.

Where can I find it?

�http://www.gimp.org/

�Download

� http://www.gimp.org/windows/

� http://www.gimp.org/unix/

� http://www.gimp.org/macintosh/

�Tile Cache. 2/3 of the RAM available in your system.

GIMP interface

ToolBox Image Window

Some GIMP applications

� Image manipulation.

� Edge detection.

�Motion blurring.

� Script-Fu: A scripting language designed specifically for GIMP.

� Convolution.

� Image contrast.

� Resizing images – scaling, shearing, rotating.

� Angle finder.

Image Manipulation

??

Pick ‘knotted rope’ like tool

Ctrl C + Ctrl V

Edge detection in GIMP

Edge detection with GIMP -2

Motion blur in GIMP

Result of motion blurring

Script-Fu -- Alchemy

Script-Fu –Décor--Old photo

Filters – Artistic -- Oilify

Convolution in GIMP

Image contrast

Image Contrast-2

Image Contrast-3

Resizing images

Lock aspect ratio

Aspect ratio?? = width/height of an image

Resizing images-2

Linear interpolation

Changing the zoom

Image rotation

Basic Advanced

Image rotation -2

Image rotation -3

Image rotation - 4

Image shearing

x

y Shear in the x -direction

Shear in the y -direction

Image shearing -2

Angle finder

GIMP Layers

Layers

�Can be used very easily to animate.

�Color graphics.

�Use layers for more flexibility.

Opening the layers toolbox

Add a text layer

Add a text layer

Rotate and scale text layer

Add a pattern to an image

AIM: Make the girl run on water

1. Size the two images

�Girl image 683x1024

�Water image 2592x1944

Cut a section from the water image / scale it.

2. Open the girl image and then open

the water image as a layer

Open the layers menu

3. Before we can work with the

transparency, add alpha channel to the

background

•Click on the background layer (blue highlight)

•Right click

•Click on add alpha channel

Raise background to top of layer stack

Change the opacity of the top layer

Water from the lower layer begins to show through, BUT we don’t want water to show through the object

Add mask to top layer

�Duplicate the top layer

�Now we will work with the top most layer (copy)

Add layer mask -2

•Select the background grass region of the background copy

•From top menu click Layer�Mask�Add layer mask

•Select as shown below

Mask chosen is displayed

White = opaque

Black= transparent

Activate the rest of the layers

Get rid of the selection view

Change transparency of the middle layer

Opaque

Opaque

Opacity ~50%

Noise stems from the misc. spots in the layer mask

End result