Do advanced photo tricks, for free. It's possible, thanks to The GIMP.

The GNU Image Manipulation Program, or GIMP, is a capable open source and free alternative to Photoshop. While it's not quite as easy or powerful as Photoshop, you can still make anything happen with GIMP, some know-how, and a bit of elbow grease. If you'd like to keep yourself from burning a major hole in your wallet in exchange for a bit more work, grab a copy of GIMP and check out these seven great Photoshop tricks you can do with it!

Layer Styles

http://www.youtube.com/watch?v=RuqPIo4s6BM

Layer styles are various effects that you can apply to layers, including shadows, borders, an emboss effect, and more. You can find these in the Filters menu and the Script-Fu menu. The above video is a tutorial of various layer styles from the Script-Fu menu which you can apply to your layers.

Content-Aware Rescaling

http://www.youtube.com/watch?v=SBWvi1EtXq8

One of the most touted features of Photoshop CS5 was content-aware resizing. Content-aware resizing allowed a person to take a picture (to remain uniform with the video, let's say a boat in the middle of a body of water) and resize it in a way where the aspect ratio of the picture has changed, but the boat wouldn't look squashed or stretched out. Instead, Photoshop would be smart enough to recognize that the water is the background and to remove or add as much of it as possible while resizing.

While this rescaling is awesome, it's not a Photoshop exclusive – liquid rescaling is a plugin available for GIMP which performs the same task. The above video is a great tutorial on how to use liquid rescaling correctly to achieve superb results.

Reflections

http://www.youtube.com/watch?v=dRuP9bpsuKM

Reflections can be added with Photoshop and GIMP. Sadly, however, it's harder to accomplish with GIMP than it is in Photoshop. Instead of a quick menu selection, you'll actually need to do each step on your own, namely duplicating the layer, applying a transparency gradient, and maybe a few other effects to make the reflection look real.

The above video is another great tutorial on how to accomplish this, and it will make you feel like you've done something "the hard way"...because you have! No one ever said that doing things in GIMP would be just as easy as in Photoshop, but you're definitely still able to do them.

Face Swap

http://www.youtube.com/watch?v=rtDmP8aHZlI

The face swap is a classic Photoshop trick, where you can place one face on another body, and apply those skills to various other scenarios. The procedure in GIMP is very similar to Photoshop in that you need to create an outline of the face on your own and then copy it, but you'll just have to press different buttons for ultimately the same thing.

The above video is a great walkthrough on how to do a face swap, and how to make it look realistic on the new body. You can also take a look at my own face swap tutorial, which describes the general concepts rather than how to make it look as realistic as possible.

Change the Color of Objects

http://www.youtube.com/watch?v=v2_887Lw-vo

Have you ever wanted to change the color of objects in images? You can actually do this with just a few steps in GIMP, which is very similar to what you would need to do in Photoshop. The above video outlines the process so you can soon be changing the color of just about anything!

Create an animated GIF

http://www.youtube.com/watch?v=f-9_HwRcd1A

Did you know that you can create animated GIFs with Photoshop, completely from scratch? GIMP can do the same, but it uses a different concept for creating them. In Photoshop,  the concept of frames is used to create animated GIFs – this makes it very easy to slightly move layers bit by bit to create the animation.

GIMP treats each layer as a frame for animated GIF creation, which makes it a bit more difficult. In order to accomplish this, you'll need to duplicate all layers you're currently using, and then when everything is in place you need to flatten/merge the layers together into one. So, you'd start with one set of layers, make duplicates of them all so that you have two sets of the same layers, then flatten/merge the first set to create the first frame and you'll still have the second set to manipulate for the next frame. Just don't forget to duplicate that set before flattening/merging the layers. The above video should help you visualize this process. Matt also wrote a guide on doing this.

http://www.youtube.com/watch?v=-sZYGwfcJ3A

If you want to convert a video into a animated GIF, you need another application to do this. The above video will explain this in detail. Don't forget that you can delete frames you don't need once the video has been converted.

Cartoonify

gimp-cartoonify

Another neat feature of Photoshop is the ability to easily "cartoonify" an image. GIMP also has a quick way of accomplishing the same feat. Jessica wrote an excellent guide on how to do this.

Conclusion

As you can see, GIMP is capable of plenty and is worthy of serious consideration. Best of all, GIMP is totally free, so why not take a look at it when it can do almost everything that Photoshop can without the huge hole in your wallet?

What's your most favorite GIMP trick? Is there anything Photoshop can do that GIMP can't? Let us know in the comments!