GIMP Tutorial: How To Use Gimp to Create a Cool Moving Train Sunset Wallpaper for Your Mac

In this lesson, I am going to show you how to use GIMP to turn a photo from day into evening, afternoon, and night.  I am also going to show you how to take those photos, and put them together, to make a cool wallpaper (if you’re running a Mac).

My Picasa page has the final photos available for download if you would like to simply skip the tutorial, and create the background.  Here is the link to the photos

Suggested Prerequisites:
Layer Mask Gimp Video Tutorial
Layer Mode Gimp Video Tutorial
Adjusting Colors Using Gimp
Layers and Selections Gimp Video Tutorial
Suggested Items:
Wacom Tablet (For Shading and Masking)
My eBook on Layer Masks - This short and inexpensive book focuses on one thing -getting you insanely good at making Layer Masks.  If you get good at layer masking, you'll get good at Gimp.

Here’s the photo we’re going to work with:

The photo can also be downloaded Here

I took this photo on a cloudy day.  This makes for a semi-dull photo.  We’re going to make that photo vibrant, full of color, and at different times of the day, like this:

This

And This

 

And This!

Part 1 – How to Edit The Skyline.

Getting the skyline is probably the most time-consuming, and tedious part of this tutorial.  Once it’s traced, we will be able to use our path throughout the rest of the project.

Zoom in on the left side of the photo, at the fence.  Using the path tool (shortcut key B), slowly trace the skyline, going around the fence, train, and everything else.  If a mistake is made, hit CTRL Z to undo your last click.

 

This part takes a while.  It's very important to get it right, otherwise your sky will look funny.  You can always hit CTRL+Z if you make a mistake.

Tweak completed path to perfection.

Using path tool (shortcut key B), trace the interior spaces around rails on the front of the train

Tweak completed interior paths to perfection.

Switch to paths tab, right-click on sklyine path, and click “path to selection”

Path to selection will create a selection off of the skyline path we created earlier.

Right click on each interior path, and click “add to selection”

Create a new layer

Right-Click on the new layer, click “add layer mask” set to “Black”

The layer mask will determine what is hidden, and what is visible within a layer.

Using the bucket tool, fill the selection white.  Your thumbnail in your layer mask should look something like this:

Deselect all by clicking select>>>>none or hit CTRL+SHIFT+A

Part 2 – How To Change The Skyline

Now that we have the layer mask in place, we can create the sky in several different ways with a gradient (called blend in GIMP.)

Be sure the proper layer is being edited (not the layer mask) and create a dark blue to light blue gradient using the blend tool (shortcut B).  Mine looks like this:

The sky looks vibrant, but something is still missing.

Create a new layer above the skyline gradient you just made.  Fill it with a sea-green color.

Set the layer mode to Overlay.  and adjust the opacity to something you’re happy with.  I set my opacity to 30.

Your afternoon train photo should look something like this:

Adding the slight sea-green tint helps.

Part 3 – How to Create the Evening Skyline

The Evening is probably the easiest part of this process, since you’re pretty much taking what you’ve already done with the afternoon photo, and replacing the blue gradient with an orange gradient.

Hide the skyline gradient, and the overlay layers that were previously created

Duplicate the skyline gradient layer that was previously created, and make the duplicated layer visible.

Using yellow, and orange colors – create a radial gradient for the evening skyline.  Mine looks like this:

With the power of the layer mask, changing the skyline is simple.

Create a new layer above the skyline gradient you just created.  Fill it with a bright-orange color.

Set the layer mode to Overlay, and adjust the opacity to something you’re happy with.  Again, I set my opacity to 30.

Your evening train should look something like this:

The orange overlay creates the "evening sun" look.

Part 4 – How To Edit The Photo To Make the Day into Night

Creating the night part consists of 4 layers, the skyline layer, overlay layer, and two darken layers. We’ll create the skyline and overlay layers first. The process is very similar to what we did with the evening.

Hide the skyline gradient, and the overlay layers that you just created

Duplicate the skyline gradient layer that you just created, and make the duplicated layer visible.

Click select>>>>all, or press CTRL+A.

Delete the skyline gradient from your duplicated layer.  Edit>>>clear, or press DELETE

Using very dark blue, and less-saturated dark blue – create a radial gradient for the night skyline.  Mine looks like this:

Now that we have the night skyline, let's see what we can do about making the rest of the photo look dark.

Create a new layer above the skyline layer you just created.  Fill it with a very dark blue (darker than navy blue).

Set the layer mode to Overlay, and adjust the opacity to something you’re happy with.  This time, I set my opacity to 90.  Mine looks like this:

The dark-blue overlay effectively added some of the shading, but the photo is still to bright.

Now we’ll create two more “night maker” layers.  One over the entire photo, and the other specifically for the ground.

Create a new layer.  Fill it with black.

Set the layer mode to Grain Merge, and adjust the opacity to something that makes the train as dark as you want it to be.  I set my opacity to 50.  Mine looks like this:

That's better, but the ground is still just a little too bright.

Right-click on any of the skyline layer masks, and click “mask to selection”

By turning our skyline mask into a selection, we have selected the sky.  We want to select everything but the sky, that's where invert selection comes in.

Invert the selection by clicking Select>>>>invert, or press CTRL+I

Create a new layer

Add a new layer mask, again setting it to black.

Fill your previously made selection with white.

Deselect all by clicking select>>>>none or hit CTRL+SHIFT+A

Using the lasso tool, create a rough selection, like the one below:

Thanks to the layer mask and how dark the photo is, there is no need to accurately select edges.

Ensuring that you’re filling the layer with color, not the mask, with Fill the selection with black.

Deselect all by clicking select>>>>none or hit CTRL+SHIFT+A

Your photo should look something like this:

Some people may argue this is too dark.  What do you think?  I thought it was, so I tweaked the opacity.

Adjust the layer’s opacity to something you’re happy with.  I set my opacity to 50.

Your final night photo should look something like this:

Now it's dark enough to get the "night" feeling, but not so dark that it washes detail out.

Part 5 - How to Dramatize the Photo

This part is entirely optional. We’re going to add four gradients to the edges, which sometimes will make a photo seem more exciting.

Hide all layers except for the background layer.

Create a new layer above all the rest, set its layer to overlay.

Set your foreground and background colors to black and white by clicking the button in the bottom-left corner of your tool palette.

Click on the blend tool (shortcut key: L)

Set the gradient to “FG to Transparent”

Darken the sides by creating 4 gradients over each of the four sides of the photo.  Hold in control to keep your gradient line straight.  Your photo should look something like this:

Notice the slightly darker edges.  This technique tends to pull the eye to the center of the photo.

Part 6 - How to Create the Background for your Mac

Now that all of the layers are created, it’s time to export each version of the train.

Create a folder to put the photos in.  Do not put any other photos in this folder.

Turn on the blue skyline, and the sea-green overlay layers.  It should look something like this:

Click File>>>Save As>>>>Save the file as: Train2.jpg inside the folder previously made.

Hide the blue skyline, and sea-green overlay layers.

Turn on the evening skyline, and the bright-orange overlay layers.  It should something look like this:

Click File>>>Save As>>>>Save the file as:  Train1.jpg inside the folder previously made.

Save this photo a second-time - Click File>>>Save As>>>>Save the file as:  Train3.jpg inside the folder previously made.

Adjust the opacity on the FG to Transparent blend layer previously created to 25

Hide the evening skyline, and the bright-orange overlay layers.

Turn on all four night layers.  The photo should look something like this:

Click File>>>Save As>>>>Save the file as: Train4.jpg inside the folder previously made.

Right-click on your deskop, and click “change desktop background”

Yes, that really is my wallpaper.  It glows.

Click on the “+” icon in the bottom-left corner of the window that appears.

Browse to the folder containing your photos

Click “choose”

Ensure that the check box beside “Change Picture” is checked

Ensure that the drop-down menu reads “Every 5 seconds”

Your window should look something like this:

Close the window.

That’s it!  Your desktop should now cycle through each photo, emulating morning, afternoon, evening, and night.

To my fellow GIMP users, how would you have done this?  How would you have edited this photo differently?