In this exercise we'll try out some basic photo editing using the commands available in the Menu Bar and Toolbox for GIMP. We'll end up with this very basic edited image:
Before we start I recommend you set up a folder on your computer to hold your files and work associated with these tutorials. If you're not comfortable setting up new folders though, just try to remember where you save the materials you are using/creating.
Now, we need a picture to work on. The one we'll be using is a free photo licensed under the Creative-Commons agreement, which means that we're not infringing on anyone's rights by using the photo for non-commercial purposes.
1. Go to Picasa's Featured Photos page to get the photo. The photo is named Vienna 2010 and looks like this:
2. You'll see a thumbnail image of the photo on the page I've linked you to. Click on the thumbnail to open the image, then right click on the image and select Save Image from the menu that pops up. Be sure to either save it in your new folder for these tutorials or to remember where else you've saved it.
3. In GIMP, click on File in the Menu Bar, then on Open in that menu. Navigate to where you saved the image and open it.
4. The first trick we're going to do is to crop the image to a specific area. Click on the Rectangle Select Tool in your Toolbox. Click and drag in the image to select a small area around the tail fins of the planes. The selection will appear as an area surrounded by dotted lines with squares (handles) on the corners and should look something like this:
5. Now that we have that area selected we will crop the photo to include only the selection. Click on Image in the Menu Bar and click on Crop to Selection in the menu there. You should now have this:
6. It's a very good idea to save your work as you go along. Click on File--Save As (from the Menu Bar) and save the new image as tail_fins.jpg in your tutorial work folder. A dialog box will pop up showing some options for JPG files. Just click on through it without changing any settings for now.
7. Now, we'll change the size of the image by scaling it. We'll be making it larger, but you can also make an image smaller using these same steps. Click on Image--Scale Image in the Menu Bar. This dialog box will pop up:
7. Now, we'll change the size of the image by scaling it. We'll be making it larger, but you can also make an image smaller using these same steps. Click on Image--Scale Image in the Menu Bar. This dialog box will pop up:
9. I am going to use the Clone Tool next. You may or may not need to depending on whether the cropped image you created has any flaws. I need to fix two areas in my image (the two black bumps that are showing up on the plane body under the fins):
10. Cloning is a little bit more complicated than what we've been doing, but give it a try. There is an Edit--Undo command in the Menu Bar you can use to undo anything you wish you hadn't done.
11. First you need to zoom in on the image so you can see what you're working on better. Click on View--Zoom--Zoom In from the Menu Bar and select 2:1 (200%) there.
12. You need to set a Brush Style to use with the Clone Tool. In the Toolbox, halfway down, are a row of icons for different dialogs that will appear in the bottom half of the Toolbox. (We talked about these in the previous tutorial.) Click on the one for the Brushes Dialog and select a medium sized round brush style.
13. Go to Tools--Paint Tools--Clone Tool in the Menu Bar to activate the Clone Tool.
14. Hold down CTRL and click on an area of the image near the flaw that you'd like to clone over the defect. Then click on the defect. If you don't eliminate the whole defect on the first click just move over the remaining defect and click on it. For my second defect, I again CTRL-Click near it, then click on the defect to get rid of it. If any of these steps go wrong for you, remember that you can use Edit--Undo from the Menu Bar to undo them. In fact you can undo several steps you have taken using that feature. After one undo, I got the defect out well enough to suit me, and here is the result:
15. I don't know about you but with all the changes and saves I've done my image is looking pretty pixelated (the square pixels are getting too distinct) and this is not good:
16. So, we'll fix the pixelation next. First I want to select just the tail fins and none of the background since they're mainly where I see the pixelation. In the Toolbox, click on the Fuzzy Select Tool to activate it. If you're not seeing settings for this tool in the bottom half of the Toolbox then click on the first icon of those dialog icons, and it will take you back to your Tool Options Dialog.
17. For the Fuzzy Select Tool, set the Threshold to about 40. Nothing else should need to be changed.
18. Click in the red area of the front fin. At this threshold setting a selection should appear around all the red on all the visible fins except for a small light red area at the bottom of the first fin.
19. Let's add that light red area to the selection. Hold down the Shift Key and click in the light red area. It will now be included in the overall selection.
20. To fix the pixelation in the selected area we're going to blur it. Click on Filters--Blur--Gaussian Blur in the Menu Bar. Set the horizontal and vertical radius for the blur to 10 in the dialog box that pops up and click on OK.
21. Click on Select--None and you should see a clearer, less-pixelated picture. It improved mine considerably:
In this tutorial you've learned how to crop your images, scale them to a different size and clean them up a bit using the clone tool and a gaussian blur. In the next tutorial, we'll move on up to some more advanced work to create an abstract picture starting with a blank canvas.
Here's a quick review of what we've covered in this tutorial:
1. You should create a folder on your computer to save your work on these tutorials.
2. Photos licensed under the Creative-Commons agreement may be used for non-commercial purposes without infringing on the creator's rights.
3. Picasa has a Featured Photos page where you can find photos to use.
4. Once you save a photo on your computer, you open it in GIMP using the File--Open command from the Menu Bar.
5. To crop out unwanted parts of an image, use the the Rectangle Select Tool from your Toolbox to select the area you want to keep. Then click on Image--Crop to Selection in the menu bar to remove all other parts of the image.
6. Save your work frequently in GIMP, using the File--Save As command. If you give the image a slightly different name as you progress, you'll be able to return to a previous version of the image if needed to correct errors...or if you want to try some other tricks on the image.
7. To make an image larger or smaller use the Menu Bar command Image--Scale.
8. If you want the image to be a different size but the same proportions when scaled, change the value in either the Width or Height box, and then just click in the other.
9. You can use the Edit--Undo command in the Menu Bar to step back through changes you've made since you last saved your image if you get an undesired result.
10. Zoom in on your image before using the Clone Brush so that you can more precisely see what you're doing. Use the Menu Bar command View--Zoom--Zoom In to do this. (Or you could use the status bar at the bottom of the window.)
11. In the Toolbox, when you want to use any paint tool (Paintbrush, Clone Tool, Airbrush, Pencil, etc.) You can set the brush style by switching to that dialog for the bottom half of the Tool Box.
12. To correct a defect using the Clone Tool, select the tool using the icon in the Toolbox, the CTRL-Click in an area that looks like what you want the corrected area looks like. Once you've done this, click on the flaw to cover it with the improved appearance.
13. You can select areas of your image that are the same color using the Fuzzy Select Tool.
14. By raising or lowering the threshold for the Fuzzy Select Tool you can change how sensitive it is to changes in color when selecting an area.
15. To add an area to a selection, Shift-Click on it while the select tool is active.
16. You can lessen pixelation in your image using the Menu Bar command Filters--Blur--Gaussian Blur.
17. To unselect a selected area in your image use the Menu Bar command Select--None.
9. You can fix flaws in your image using the Clone Brush.
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