Gimp Image Processing

Gimp Image Processing Software
Gimp Image Processing
Gimp Image Processor

GIMP (/ ɡ ɪ m p / GHIMP; GNU Image Manipulation Program) is a free and open-source raster graphics editor used for image manipulation (retouching) and image editing, free-form drawing, transcoding between different image file formats, and more specialized tasks. GIMP is released under GPLv3+ license and is available for Linux, macOS, and Microsoft Windows. Gluas is a gimp plug-in providing a enviroment for testing algorithms for image processing. The environment contains a simple editor for entering the algorithms. It uses the lua interpreter. Gluas can be downloaded from Gluas download page, to be able to use gluas properly you also need an installation of The GIMP.

Photoshop isn't. Astrophotography can become an (expensive) obsession but it can also be a casual pleasure. Most (i.e., ALL) astrophotos need some gussying up. These steps are a start - the images straight out of the camera are not very impressive.
GIMP is a cross-platform image editor available for GNU/Linux, OS X, Windows and more operating systems. It is free software, you can change its source code and distribute your changes. Whether you are a graphic designer, photographer, illustrator, or scientist, GIMP provides you with sophisticated tools to get your job done.
Go to File Open in the Main Menu. The Open window will pop up. Navigate to any RAW image file you have, highlight it, and click Open. If a funky looking window opens up with your picture in it (looks like the image above), you already have UFRAW installed.

Beginner¶

GIMP Quickies
Use GIMP for simple graphics needs without having to learn advanced image manipulation methods.

Simple Floating Logo
This tutorial walks through some basic image and layer manipulation techniques.

Making a Circle-Shaped Image
How to create a circular-shaped image.

Layer Masks
An introduction to using layer masks to modify the opacity of a layer.

Basic Color Curves
A first look at the Curves tool and adjusting color tones in an image.

Gimp Image Processing Software

Your GIMP Profile (and You)
What the GIMP Profile is and how to use it.

Image Formats Overview
Selecting the best image format for your purposes.

Gimp Image Processing

Asset Folders
Extending GIMP with new plug-ins, scripts, brushes, and more.

Photo Editing¶

Digital B&W Conversion
Detailed conversion tutorial for generating a B&W result from a color image.

Luminosity Masks
Using multiple layer masks to isolate specific tones in your image for editing.

Tone Mapping with ‘Colors/Exposure'
Using high bit depth GIMP's ‘Colors/Exposure' operation to add exposure compensation to shadows and midtones while retaining highlight details.

Focus Group
Layer masking and creative filter applications.

Painting¶

Parametric Brushes
A look at the advantages and flexibility of using Parametric Brushes.

Gimp Image Processor

Programming¶

Basic GIMP Perl
Learn how to write simple perl scripts using the gimp-perl module (GNU/Linux users only).

Salmon hue lipstick. Automate Editing
Using GIMP Python to automate a workflow.

Automatic Creation of XCF from JPG
Import XCF images a directory at a time.

The list of legacy tutorials can be found found here:

Bear in mind that this list is being provided for legacy reasons only.

Table of Contents

Preface

1. Digital image representation

Vector images

Coordinate system
Defining shapes

Bitmap images

Sampling
Image compression

File formats and applications

2. The gluas environment

Installing gluas

Windows
In Linux, from source

Using gluas

The lua language
Setting and getting pixel values
Shadow buffer
Samples

A simple program

Gluas reference

Functions
Variables

Gluas compatible software

3. Visual Debugging Aids

Histogram
Chromaticity Diagram
Luminance Profile

4. Point operations

Threshold

Brightness

Contrast

Brightness + Contrast

Invert

Gamma

Levels

Curves

Lookup tables

Excercises

1. Exchange Red and Green
2. Value boost
3. Checkerboard
4. Position dependent contrast

5. Area operations

Sampling area

Edge handling

Convolution Matrix

Smoothing filters

Box blur
Gaussian blur
Speeding up blur by decomposing
Edge preserving

Rank/statistical filters

Median

Unsharp mask

Misc area filters.

Jitter

Excercises

1. Extend the convolve example
2. Adaptive blur
3. Circle

6. Resampling

Affine transformations

Translation
Rotation
Scaling

Other transformations

Perspective transform
Lens correction

Interpolation

Bilinear interpolation
Bicubic interpolation

Decimation

Trilinear interpolation

Excercises

1. Interpolation error visualization
2. Study the assignment

7. Automatic color adjustments

Contrast stretching

Automatic white balance

Grayworld assumption
Component stretching

Automatic spatial algorithms

Local Contrast Enhancement

Excercises

1. Problems with the Local Contrast Enhancement filter

8. Countering artifacts

Static sensor noise

Film grain

CCD sampling noise

Quantification

Interlacing

Line doubling
Linear blend
Temporal resampling

Aliasing

Color casts

A. Assignment, spring 2007

Introduction
Goal
Report
Dataset
Hints