Includes very basic tutorial for new GIMP users.
The first part of this tutorial is very easy and includes GIMP basics such as opening as layers & resizing (scaling). Tips work for all GIMP image editing not just making icons.
New GIMP users should start with part 1, all other users can skip to part 2.
If you have just installed the program, before starting, I advise you to have set up your GIMP windows so that from one of the docked tabs, you can view the Layers Dialog. From there you will be able to manage and adjust the layer properties to follow this tutorial. Also it would be helpful if you know the names of the tools in the Main Toolbox.
If you cannot view the layers dialog window, or docked tab, or you are totally unfamiliar with these items, just follow these easy instructions here http://docs.gimp.org/en/gimp-concepts-main-windows.html from GIMP.org to set up your main windows and to review the GIMP tool box.
It also will help to know where the "Undo" option is on the tool bar because almost everything can be undone when using Gimp.
Part I.) Creating a Simple Icon or an Icon Base for Beginners (Starting to Work with Templates and Layers)
1. Step one is to create a new image. Click on File>New and from the drop down list in the New Image Dialog, select your template.
Choose Icon (100x100pixels). Then click to view Advanced Options and be sure the Color Space is listed as RGB.
The image window will open with the blank icon. In the Layers palette this is automatically made the "Background".
2. Step two is to add your image to the background layer. There are two ways of doing this, you can add the image as a layer or open the image in it's own window, and copy and paste it into the background. For this tutorial I'll be using the first option because it my opinion is it easier.*
On the image window, click File>Open As Layers then select the image. You can now see the image is open on the Layers Dialog.
If you wish to rename the new layer you can do so by double clicking on it's current name, but it is not required.
Before the next step you can save your project as a .XCF (Gimp document). Go to File>Save As if you're saving often in between steps, you don't have to worry about losing your projects.
3. Step three is to "crop" or resize the image to fit the background. To do this you will use the Scale Tool.** Always be sure the layer you want to resize is the active (selected) layer (you can see what is selected by viewing it in the Layers Dialog). The GIMP default interpolation is Cubic, you can use that or change it to one of the other options. (I use Sync (Lanczos3) for shrinking large images because it seems to preserve image details better - at least on my monitor.)
Important: When resizing images, always check "Keep Aspect" or your images will not have the correct ratio and they will be distorted and stretched.
Now, with the Scale Tool selected, click on the image. The Scale options dialog will open. You can scale your image until you like how it fits in the background. You might need to switch between the Scale and Move tools to place the layer properly.*** (Our picture was scaled down quite a bit as seen below. I wanted to crop out the text so I positioned it as seen.)
4. Step four, is to flatten the layers of the image and so finalize the cropping of our layer. Click on Image>Flatten Image. You will see that there is now only a single background layer in the Layers Dialog.
Step 5. Now, you can save your new icon. Go to File>Save As> and type in a name and choose .PNG or .JPEG as the file type. Now you can use your icon on Livejournal!
You can continue with part two of the tutorial (coloring and enhancement) if you're ready or if you already know all about part one, you can start here.
Part II.) A Super Simple Color Enhancement in Seven Easy Steps
For step 6 of this tutorial you'll need to know how to make a color, or how to use the built-in Gimp Palettes.
This coloring works on images that have medium bright light levels and low or medium color saturation (see the examples below for more results).
This tutorial only uses the built-in default Gimp filters and color tools.
1. First, open and resize your base ( for this tutorial the base is same as the image in #5 above) and go to Layers>Duplicate Layer. Duplicate your base one time.
2. With the top layer selected Go to Colors>Auto>White Balance. (This is just to adjust the color levels really quickly).
3. Duplicate base three times. Select the top layer and go to Filters>Blur>Selective Gaussian Blur. Leave the default settings and apply the filter.
The results look like a smeared painting, but that is OK for now, it will look better later. From the Layers properties drop down list, set this layer to Overlay and adjust the opacity to 50 to 80 percent. This layer is meant to add color richness and depth and quickly smooth out skin tones and smooth pixelated images. For darker images less opacity on this layer is better.
4. Select the layer below the overlay one, and set it to Screen. Set the Opacity at 30 to 70 percent, depending on how bright you want the image. Keep in mind too much brightness would ruin the details of our subject's eyes and face. The effect should be a "shiny" soft glow when seen through the over-layed top layer. For bright base images, less opacity on the screen layer is better.
Again, flatten image.
5. Next is the fun part, coloring! Duplicate base three times. It looks all right, but I prefer to reduce the yellow of the image a bit and make it more "dramatic" and contrasted.
With the top layer selected, go to Colors>Auto>Color Enhance and then set the layer to screen at 40 to 50 percent opacity.
6. Edit Coloring. Create a New Layer from the Layers Menu on the tool bar or from the Layers Dialog. The layer should be (100x100 pixels and transparent). Now select the Bucket Fill it with Sky Blue 1 ( #87ceff) from the Named Colors Palette (or make this color yourself using the code given). Set this layer to Burn and set the Opacity at between 20-50 percent. This depends on how dark you want the blues and shadows to look.
7. The final step is to enhance by sharpening the image. Duplicate base twice. Go to Filters>Enhance Unsharp Mask (leave setting at default****). Next, use the Eraser Tool to erase all areas of this layer except for selected areas of the facial features (eyes, mouth), we want these parts of the image to look clear but not over contrasted. This will depend on your monitor display and your personal taste, etc. Now, lower the opacity of this layer to about 50 percent (or lower).
Save as .PNG or as a high quality .JPEG.
* Sometimes you might want to do the latter and edit it before adding to the background, but that is for another lesson.
** Alternate option is to go to Layers>Scale Layer
*** If the layer disappears on resize, just zoom out until you can see it's edge as a selection. Then use the Move tool to reposition it on the background.
****Unsharp Mask defaults are:
Here are a variety of before and after images, you see the results vary. (All of these images are television related but the tutorial should work and any kind of stock.)
Please feel free to leave questions and feedback. This is my first GIMP tutorial so if it's confusing, and tends to switch between first and second person, sorry. I will fix grammar errors later.
Credit for the Evangeline Lilly photo goes to lost-media.com