EDAD660 (2010)

This tutorial is based largely on a PhotoShop tutorial set authored by John Kuiphoff.  The original version of this tutorial, including directions on how to accomplish these tasks within Photoshop, can be found here.  The materials referenced in this exercise can be downloaded here (ZIP File).  You can download a free copy of Gimp by clicking here.

Tutorial #1: Rotating an Image

This is probably the most basic task that you’ll be called upon when working with digital images.  You can easily rotate the entire canvas of an image in Gimp by doing the following:

1. Open an image
2. Click on the Image menu
3. Highlight the Transform submenu
4. Select the operation you wish to use (i.e. Flip Horizontally, rotate 90 degrees clockwise, etc.)
5. Save your image (File -> Save As)
6. If the image is photographic in nature, save it as a JPEG.  If not, save it as a PNG file.  Adjust the JPEG quality settings as necessary.

Tutorial #2:  Resizing an Image

Modern digital cameras take ultra high quality photographs that print out beautifully. However, using these high quality photos in an online environment, such as your blog, is generally not advised. Larger image sizes take much longer to load in, and they will eat up your available space on Globalblogs, Edublogs or any of the other major blogging services. Here’s how you can resize your image to be a bit more manageable:

1. Open an image
2. Click on the Image menu
3. Click Scale Image
4. Type in a new size in the width and height boxes.  Changing one value will change both, so your image stays in proportion.

Web images generally work best in the 300-700 pixel range.  Images on our class blog are generally shrunk down to about 300 pixels to minimize load time.

Tutorial #3:  Levels

Adjusting the color levels of a photograph is probably the easiest thing you can do to improve the quality of your picture.  Here’s how you can get started:

1. Open an image
2. Click on the Colors menu
3. Click on Levels
4. Here you will see a graph of the color values present in your image.  At the bottom of the graph are three sliders.  Grab the first sliders and move it such that it appears close to the beginning of the graph.
5. Grab the last slider and move it so that it is near the end of the graph.
6. Like magic, your image quality will improve – sometimes dramatically!

Tutorial #4:  Contrast

Sometimes you need to make an image “pop out” a bit more.  Adjusting the contrast can sometimes help.  Here’s how to get started:

1. Open an image
2. Click on the Colors menu
3. Click on Brightness – Contrast
4. Adjust the sliders accordingly

Tutorial #5:  Color Adjustment

You can easily adjust the color balance of an image to add more red, green and blue colors into the environment by doing the following:

1. Open an Image
2. Click on the Colors menu
3. Click on Color Balance
4. Adjust the sliders accordingly

Tutorial #6:  Fixing Damaged Photographs

Sometimes you need to “clean up” an image that has been (physically) scratched or damaged.  Here’s how to use the “virtual skin graft” tool to do this

1. Open an image
2. Click on the “clone tool” (looks like a rubber stamp)
3. Identify a rip that you would like to fix
4. Hold down the CONTROL key and select an area that appears to be undamaged close by the ripped area
5. Click on this area
6. Release the CONTROL key
7. Now move your mouse over to the ripped area and hold down your mouse.  Move it around to cover the area.

This technique works best if you zoom very close into the image.  You can zoom by using the percentage drop down box that is located at the very bottom of your image.

Tutorial #7:  iWarp

iWarp is a distortion tool that lets you exaggerate, shrink, move and spin portions of an image.  Here’s how to get started

1. Open an image
2. Click on Filters -> Distorts -> iWarp
3. Use the tools in the iWarp menu to modify your image.  For example, to make someone’s eyes bigger, simply click on the ‘Grow’ button and then click on their eyes.  Make sure that you click on the small preview image inside the iWarp menu and not your main image.
4. When you are finished click the OK button to apply the changes to your image

Here’s the Dove video that we watched in class that illustrates some of these techniques in action:

Tutorial #8:  Filters

Gimp has some built-in special effects that can be used to create interesting effects on top of your image.  Here’s how to get started:

1. Open an image
2. Click on the Select Menu and choose All
3. Click on the Filters menu and select a filter.  Each filter operates in a slightly different way, but in the end the filter will apply a new effect to your image.
4. Filters can be combined and layered on top of one another to create a wide range of interesting effects

Tutorial #9: Combining Two Images

You can easily combine elements from multiple images into the same image using Gimp – here’s how:

1. Open up two images – we will copy content from one image and bring it into another. In my example in class I used one file that contained 8 fish and another that contained a small aquarium scene.
2. Use the lasso tool (third tool in the first row) and select a portion of the first image (the fish) – try and stay as close as possible to the image to create a smooth cut-out.
3. When you are finished, connect your beginning and end stroke.
4. Click on the Edit menu, and then on Copy
5. Switch over to your second image (the aquarium)
6. Click on Edit -> Paste as Layer
7. Use the move tool (third row of tools, second tool in) to move your object around.
8. Use the scale tool (fourth row of tools, first tool in) to resize your item.  Click the Scale button in the pop-up dialog box to accept the resizing once you are happy with it.