Wendy, Steve, and Emma’s Blog

When GIMP starts up it opens three windows by default. These windows show up in your taskbar (at the bottom of your screen) as “GIMP”, “Layers, Channels, Paths, Undo  | FG/BG, Brushes, Patterns, Gradients” and “GIMP Tip of the Day”. The “GIMP Tip of the Day” dialog has a checkbox on it that asks if you want to show this window the next time you start up. Personally, I uncheck this box on every program that has a similar window, but before closing it I click on “Next Tip” and read every tip until I get through them all or until I’ve gone through a good amount of them. Often the tips provide great information about functionality that you would never have known existed before. I definitely recommend doing this with GIMP because its tips are actually quite good at giving you a heads up to how GIMP works.

And don’t ever forget to use a program’s help menu and to use Google. If you come across a word that you don’t understand (such as “Alpha Channel”) just use the help menu and if that doesn’t help then use Google.

Opening an Image in GIMP 

You’ll need to upload the pictures from your camera to your computer. I have to assume you know how to do this. When you do this, be sure to put the pictures in a place on your computer that makes sense (perhaps in a folder called “Photographs” and be sure you know how to navigate to this place using Windows Explorer).

Now use GIMP to open your picture for editing. Do this by clicking on the GIMP window’s “File” menu and selecting “Open”. Then double click the left-hand set of nodes (one node will say “C:\”, for example) to navigate to the image you want to edit on your hard drive and double click it or select it and click “Open”. Notice that when you select a picture it shows up in the right hand “Preview” section of the window.

When you open the picture it opens in a new window that is dedicated to that picture. One nice thing you’ll see right away is that on the outskirts of the picture will be what looks like a ruler. There is one that runs vertically on the left side of the picture and one that runs along the top of the picture. This tells you the number of pixels (the tiny little dots on screen that form your image) that make up your image. If you’ve opened up a freshly uploaded image from your camera the numbers will likely be pretty large. In my current window I have opened up a newly uploaded image and its size is roughly 1800 pixels wide by 1800 pixels tall.

This is a good example of a picture that is really too large for sending to people and certainly too large for putting on a digital picture frame. Instead of leaving the image like this we’ll resize it. However, before resizing it there is something you should understand: Creating a copy of the original image.

Tips For Saving the Original Image  

We first want to save the image as another image so that we preserve the original picture.  This way if we make a mistake we still have the original picture to start fresh from again. So, in the window displaying the picture click on the File menu and click “Save As…” A new dialog box will open that asks you the name of the file you want to save, and it will automatically save it in the same directory (folder) on your computer that you opened the picture up from. Give the picture a sensible name so that by viewing it you’ll know what it is. It’s a good idea to give it a name without any whitespaces in it. So, instead of giving it a name such as “Emma at Christmas”, give it a name of “EmmaAtChristmas”. The trick is to capitalize the first letter of every word. Saving files like this is a good practice because if you put whitespaces in file names some programs have difficulty with the file….and you want to avoid headaches that you don’t understand, don’t you? The other trick to naming image files that I follow is that I always put a number on the end of them. For instance, if I’m saving a Christmas shot of Emma, I would call it something like “EmmaChristmasOne” because I’m likely to have other Christmas shots of Emma and this way I can have a list of them with similar names.

If you accept the default name of the image that GIMP puts in the box for you, it will actually overwrite the file that you opened at the beginning—which is something we don’t want to do because we’re trying to leave the original image file undisturbed.

Tip: Image Quality Greatly Affects the Image File’s Size 

Before GIMP saves the image it asks you the quality of the image you want to save. This is very important because the higher the quality the larger the file will be…and part of what we are doing here is trying to save the smallest file while also maintaining acceptable image quality. Until you are completely done working with the picture, always choose 100% because then GIMP will not decrease the quality of the picture while you are working on it (you want to work with the best quality picture you can have). Once you are done working with the picture you can then play around with the quality to get the smallest size file that also pleases you in terms of quality. Fool around with this dialog a little this first time through by checking the “Show preview in image window” checkbox and adjusting the quality slider (or clicking on the up and down arrows in the tick box at the upper right). Checking the “Show preview in image window” causes your quality adjustment to display on the image you are working with, which is helpful when you’re trying to determine where the “sweet spot” of quality is.  Also pay close attention to the size of what the saved file is, which is shown right above the “Show preview in image window” checkbox. Pull the slider all the way to 100%, look at the file size, and then move the slider to 50% and compare the file size. In my window at 100% I have an image that is 1061.4 KB; when I move the slider to 50% it is 133.1 KB. However, when I look at the difference between the two in terms of what the image looks like, I can barely tell at all. Yet the size of the file at 50% is 12% of the file size at 100%. This is a great example of how much smaller you can get a picture but still retain perfectly acceptable quality.  Just think, by playing with quality like this we just allowed a digital picture frame, for instance, to hold eight times the number of pictures than it would hold if we saved everything at 100% picture quality…and on the picture frame you’ll never even notice a difference.

Note: KB stands for “Kilobyte” and means “one thousand bytes”. In my example above this means at 100% quality I had 1,061,400 bytes and at 50% quality I had 133,000 bytes. A byte is a unit of storage on the computer, so instead of saving over 1,000,000 bytes I could potentially only save 133,000 bytes, which is a huge difference.

Also, once you have successfully saved the file and given it a new name, at any time while you are working you can click on “Ctrl-s” (type the Ctrl key and the ‘s’ key at the same time) and it will be saved for you. As you’re working with the image do this a lot so that you don’t lose your work. (You can also go to the File menu and click “Save” but using the keys is a lot faster).

Note: The following section uses the ‘|’ character as a way of drilling down into menus. For instance, at the top of your screen containing your loaded image you’ll see an “Image” menu. If you click on it you will then see a “Transform” menu item, which when hovered over will show you another menu. If I am instructing you to rotate an image 90 degrees clockwise, instead of writing a lot of words to instruct you how to do this I will instead write “Image | Transform | Rotate 90 Degrees Clockwise”.

Note: Any action you take in the program (or just about any program) can be undone using the Ctrl-z keystroke combination. For example, if you rotate an image in the wrong direction, don’t worry!  Just type the keys Ctrl and z at the same time and the action will be reverted. You can also choose the Edit | Undo menu item but it takes longer.

Now Down to the Fun: The Most Important Ways to Manipulate the Image

1. Rotating the Image: Since the image you are looking at might not be rotated correctly (depending on how you took the picture), you can use the Image menu’s Transform menu to rotate the image. Image | Transform | Rotate <direction of rotation>
2. Zooming In/Out: In order to “touch up” a picture, it is often very helpful to zoom way in to a specific part of the image so that you get a really close up view.  To do this type the ‘+’ key (using the Shift key at the same time) and to zoom out use the ‘-‘ key.
3. Moving the Image: Okay, so now you’ve zoomed in on a face but you’re looking at a hand instead of eyes? Click on the GIMP window’s “Move” button (remember, there is a window on your taskbar at the bottom of your screen that says “GIMP”, and this is the GIMP window). The move button has what looks like a ‘+’ character, only it’s fancier looking and it has points on each end. After you’ve clicked on this button, bring the mouse cursor to the image, hold down the mouse button, and drag the mouse and you’ll see the image move.  Now you can move the image so you can see the eyes. If you’re not happy with your move remember that you can type Ctrl-z to undo it!
4. Cropping the Image: To crop your image, use the GIMP window’s crop button. The button sort of looks like the tip of a grayed out highlighter pen (hover over any button so that you can see its name).  After you click this button you’ll click and drag the mouse to form a rectangular region around the portion of the image you like (and the rest will be discarded). When you’re done dragging the mouse, let go of the mouse button and you’ll see a rectangle. If you type the “Enter” key at this point only what’s in the rectangle will be left in your image. This is a good way to get rid of the outer boundaries of the image that you don’t want.
5. Pencil/Paintbrush/Airbrush/Ink Tool: Use these tools to draw on the image. To select a color to draw with, click on the patch of color below the buttons (it’s square and is probably black unless you’ve already changed it). This brings up a color dialog where you can select the color you want to draw with. Fool around and don’t be afraid. Remember, every time you draw you can undo what you did with a simple stroke of Ctrl-z. To draw just click on the image, don’t let up on the mouse button, drag the mouse, and then let up on the mouse button.
6. Changing the Brush: A little below the tool buttons you’ll see a “Brush” button. Click it and you can select a wide array of brushes. I use this most often to control the size of the brush I’m about to touch up with. So, if I want to tweak a very, very small area in the picture I will select the smallest brush possible. A larger tweak requires a larger brush.
7. Blurring and Smudging: You can even blur or smudge the image using the blur or smudge tool. Zoom way in somewhere (or it will probably be hard to see the results), click either of these buttons, and find a distinct part of the picture that isn’t already fuzzy.  Then drag the mouse over this part of the image a few times and if you pay close attention you’ll see the image blur or smudge. Don’t forget you can hit Ctrl-z at any time to undo your changes.
8. Color Picker Tool: This tool is priceless because you can select any part of the image and it automatically determines the color where you clicked and puts it on your color swatch so that when you use the Pencil, Paintbrush, Airbrush, or Ink Tool you’ll use this color.  Very cool.
9. Text: Click on the text tool (looks like an ‘A’) and click on the image and type a message and close the window. You’ll see the text on your image. You can select the font and color of text after you click the text tool from the controls underneath the buttons.

Layers

One of the things that new users have a hard time fully grasping is the concept of layers. Think of a layer as a transparent sheet that is placed over your picture. On each layer you can do something, but each layer is individual from other layers. For example, when you type text on your image a new layer is automatically created. Try this out now…just select the text tool, click on the image, type in some text in the dialog, and select close. If you then look at the “Layers, Channels, etc.” window you’ll see that a new layer was created. If you click and type text again another new layer will be created and you’ll then have three layers. What’s confusing about this is that if you then try the move tool and move the picture, only the currently selected layer will move—sort of like moving one of those transparent sheets in the stack. If you want to move everything at once you have a few options:

1. Hover over a layer in the Layers, Channels, etc. window, hold down the shift key, and click on the box that appears to the right of the eye symbol. This will put a lock in all the boxes in all the layers, meaning that the layers are “locked” together. You can now move everything at once, and when you’re done you can then do the same action to remove the locks from all layers.

2.  If you only want to move a subset of all the layers, just individually click on the lock boxes in each layer and then move them.

3.  If you want to “merge” all the layers together, click on “Image | Flatten Image” or if you want to only merge the visible layers click on “Image | Merge Visible Layers”

Removing Red Eye 

I’ve followed a few tutorials on the web on removing red-eye and some are quite complicated. The best results I’ve found so far is to do the following:

1. Select the View | New View menu item. This brings up another view of your image identical to the first.

2.  In the new view, zoom way in on the eye(s) you want to remove the red from. Now you can see a zoomed in view and a normal view, so anything we do in the zoomed in view you’ll be able to immediately see a normal perspective of the picture.

3. Click on the color swatch so that you can tweak the color.

4. Give the color the following red, green, and blue components: 43; 18; 22.  This is a warm, dark brown.

5. Select the Paintbrush tool

6. Select the appropriately sized brush

7. Color over the red, being very careful not to touch anything else in the image but the red…especially the twinkle in the eye if there is one. Be extra careful around the twinkle and don’t try to get too close. Get the red out but no more.

8. Click on the color swatch so that you can tweak the color.

9. Give the color the following red, green, and blue components: 36; 36; 34.

10. Select the Airbrush tool

11. Slowly click on the mouse as if you’re quickly triggering an airbrush tool. You want to leave some of the warmer color in the eye or it will end up looking too gray. Pay attention to the unzoomed view until you are happy with it. Remember, it’s the view people will have of the picture that is important, not the zoomed in view.

12. You may have to tweak the above colors a little bit.  I did this with Emma’s red-eye and when done we couldn’t tell that there ever was red-eye.

13. You might have to eliminate some red-eye from over the iris.  Just use the color picker tool to select from the iris color and then use the Paintbrush tool.  You may have to then pick a second color and dab the touch up with the airbrush tool.

That’s pretty much all you need to know to do basic image manipulation, which covers 95% of what you’ll ever want to do with a picture.  Play around with other functionality, though, and you’ll be amazed at what you can do.

And don’t forget the undo keys: Ctrl-z.