Lesson 6

Image Manipulation


Introduction

Image editing software is another common requirement for educators. Whether you’re editing images for a presentation, a website, or teaching students digital photography – you’ll need an image editor. There are many choices, and your decision on what to use in your instruction will influence how students use software throughout their own careers.

The lesson addresses these topics:

  • Image Editors
  • GNU Image Manipulation Program

Advanced Organizer

During the lesson, look for answers to the following questions  –

  1. Why might individuals or organizations look for alternatives to Photoshop?
  2. What should be the criteria for selecting an image editor for school use?
  3. What are the image editing skills that students need to know?
  4. How do you phrase learning objectives so they are not software-specific?

Walk-through

1. Browse

Three FOSS projects to be aware of are Blender, Inkscape, and the GNU Image Manipulation Program (GIMP). All are available on Linux, Windows, and OSX.

Blender is a 3D graphics product used for animated films, visual effects, 3D modeling, and video games.

Inkscape is vector graphics editor – vector graphics, unlike photos, can be resized without any loss in quality.

GIMP is a raster graphics (photo) editor for retouching, editing, free-form drawing, format conversions and more.

paul-2016-228x2492. Read: A Parent’s (and Professor’s) Perspective

Adobe’s Photoshop product is so ingrained in our minds as the “industry standard” image editor that “photoshop” is frequently used as a verb. I find that even novice users insist that they must buy (or now rent!) a license. On closer examination, many of them don’t even know why they’re buying it – and their image editing needs are fairly simple. There are online image editors that easily meet their needs (Pixlr.com for instance), even without FOSS alternatives. For an educational institution, however, I have a hard time imagining why GIMP shouldn’t be the go-to solution (aside from its unfortunate synonym and a fairly lame mascot). GIMP is powerful, flexible, cross-platform, and supports all kinds of file formats – including Photoshop’s .psd files.

With Photoshop CS6+, Adobe has joined Microsoft in vying for a line-item in your budget. They don’t want a one-time purchase, they want a monthly payment. For someone like my brother-in-law who is a professional photographer, this might be acceptable. However, for most users, I think it’s completely unnecessary. Judging by the number of internet lists for “Photoshop alternatives”, others have concluded that the “industry standard” argument isn’t enough to keep them paying. GIMP, by the way, appears on every such list that I’ve found.

Photoshop isn’t likely to be unseated as the gold standard any time soon. Adobe adds some impressive features, and I know that most professional graphic designers are Photoshop users. However, I am not a professional graphic designer, and most of your students won’t be either. If they do take advanced graphic design courses, that might be time for a Photoshop subscription, but they can learn the majority of image editing principals and techniques in GIMP.

I have a daughter in a Hawaii public school. When she gets the opportunity to take photography or graphic design courses, I hope her teachers and technology coordinators are wise enough to instruct using GIMP or other FOSS tools. As a parent, I will be pretty peeved if my daughter informs me that I need to buy a Photoshop subscription so she can work on school projects. By teaching my daughter how to use GIMP, she’ll have skills with a powerful image editing tool for her lifetime. If she goes pro and wants to use Photoshop, she’ll have little trouble transferring those skills.


3. Read Introduction to GIMP for Educators

The core of this post is to point out three areas that GIMP can benefit educators:

“1) A free and relatively easy to use tool to edit images that you may use when building presentations, handouts, worksheets, tests, web content, or any other digital or print media. Since it runs on all platforms and is free, you can use it at home as well as at school. So even if your school has Apple and you have a PC at home (or vice versa) you can still get work done on your own terms.

2) A free tool that will work on any platform including older machines that you can use to teach students concepts of digital photography, image editing, or as a tool for students to edit images used in their own reports and presentations. As we move more and more into the age of WEB 2.0 students are going to be asked to create presentations, web pages, social media and report and publish their projects for others to see and use. A tool like the Gimp gives them a tool that will let them get this job done AND can teach them concepts they may one day need in their careers as they are called upon to create reports, publish content to a web page, or do more complex tasks.

3) A tool for scientific analysis of digital images taken for scientific purposes. It is possible to strip out certain color bands, adjust brightness and contrast, take measurements, and form conclusions based upon image data. Color analysis of pH indicators or from some other chemical reaction comes to mind. Spectral analysis may be another possibility.”


4. Read Wikipedia’s article on GNU Image Manipulation Program (GIMP)

Gimp logo

  • History
  • Development
  • Features

GIMP has been around since 1996 – an impressive lifespan for any software project. It is frequently compared with Adobe’s Photoshop and is popular among amateur artists and FOSS users. GIMP includes many advanced tools for selecting objects (for example, extracting one item from a larger photo), using layers (stacking “transparencies” to create a final image), and file conversions. There are many scripts and plugins available for automating tasks or adding new effects and filters.


5. Review the GIMP website

Here you will find the latest news about GIMP, full documentation, and downloads for Linux, Windows, and OSX. The release notes section provides details on the new features since the last release.

There are a hosts of GIMP tutorials available online. Our activity and assignments will take you through some basics, but please explore further if you are interested in photography or graphics.

Activity

  1. Install GIMP
  2. Review the GIMP User Manual
  3. Note the GIMP Glossary – especially useful if you’re unfamiliar with image editing

Assignments

Note: the below tutorial use GIMP 2.6 – it is extremely similar to the latest GIMP but you may notice small differences.

Watch GIMP Basics (GIMPTRICKS) and follow along in your own installation. Expand the video to full screen for best viewing. Pause it as needed, and reference the GIMP Glossary when you hear unfamiliar terms. Use your First and Last name as the text for your image, and be sure to save the results as a .xcf file. If you have difficulty, post in our Laulima Help forum – and if you’re already good at this, look there for an opportunity to coach others. This tutorial will quickly introduce you to:

  • GIMP’s primary windows:
    • toolbox + options,
    • image window,
    • layers/channels/paths dialogues
  • Foreground/background colors and selection
  • Several tools in the toolbox (blend, text, bucket fill)
  • Selections
  • Layers

I encourage you to also explore some other common tools on your own: especially the 7 selection tools, crop tool, and healing tool. Youtube is full of GIMP tutorials, and Google will serve you well too.

  1. Join the Jedi (or the Sith)
    1. Take a photo of yourself holding a golf club, baseball bat, or broom handle and give us your best Jedi pose. Now follow along with the above video, and transform that stick into a light saber!
    2. Save your file in GIMP’s native format, .xcf. Additionally, export it as a .jpg file.
    3. Post your .jpg file in your class Blog (this is optional and ungraded, but encouraged!).
    4. Submit both of your .xcf files (one from each tutorial) in Laulima’s Assignments tool: “GIMP files”.

Additional Material

  1. Rawstudio (HTML) – for photographers that work in RAW formats
  2. Darktable (HTML) – an open source photography workflow application and RAW developer
  3. Digikam (HTML) – a powerful FOSS image manager and editor that I like to use in conjunction with GIMP
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