click image for a larger version

Gimp’s auto white balance has been pretty reliable to quickly set the correct tones in my grayish photos. See the results here:

click image for a larger version

And there you go – one click white balance correction in Gimp!

To view the Layer’s dialog box, press CTRL-L or from the Dialog menu.

Create a new layer:

Notice that in the dialog box for a new layer you can select different options. I use the “Transparent” option most of the time, so my new layer will overlay the background layer. Also notice the size of the new layer. This is where it gets tricky in GIMP. Leave it at the size of the image right now.

Next, draw a new selection on this new layer and fill it with a color. When you click on a tool in GIMP, the dialog box below the tools area will change to allow for options with that tool. Experiment a bit with that and you’ll find some cool effects.

Once you have created a new shape on the layer:

Click to see a bigger version of this screenshot

Click on the Bucket tool and fill it.

Great! You’ve created a shape that’s on it’s own layer! Now if you move that graphic around it will float independant of the lower and upper layers. Oh, wait a minute – if you move it around you’re moving a layer the size of the entire graphic, not just the shape you made. This can really get you at the end of your design when you go to print or export – you’ll have a layer that is “over the edge” of the background layer. Trust me when I say, this is pure GIMP chaos.

So, just as soon as I’m happy with a shape for that layer I use the Autocrop Layer to resize the layer to just around my shape. Then, when I move the shape around, the layer won’t go over the edges of the main background layer.

Click for a bigger version of this screenshot

Choose, Layer and then Autocrop Layer. Voila! Now, the layer is exactly the size of your shape. What’s awesome about the Autocrop Layer is if you had multiple shapes and lines on a layer it would Autocrop to the edges of all the elements.

Experiment with this and you’ll soon see Autocrop Layer is your best friend when working with complex graphic layers.

1) Click and drag a selection over the area that you want to remain as your image.

2) From the Image Menu, choose Crop To Selection

3)You now have a quickly cropped picture in GIMP!

Open Gimp and then open an image you want to try this out on, preferably a photo that needs correction and/or has a grey wash to it. If you need an image to practice on, you can download this one.

Within Gimp, on the Image’s menu bar, select Colors | Levels and this dialog box will open up.

Notice the granular adjustments you can do, however correcting most photos I’ve found can be done with just pulling in the slider triangles from each edge to the beginning of the color levels for each photo/image, like so:

What’s nice about this tool, and Gimp in general, is that as you slide the triangles the image will change accordingly. I start by pulling the triangles in to the edges of the image’s color levels and check the image. If it looks good, just click OK and there you go, easy color adjustment with the Levels tool.

Notice that on different images the Level Input area will be different, so just adjust the triangle sliders in from each side to the beginning of the color level for each photo/image for quick color correction:

Ok, now that you’ve got Gimp, lets rock the crop! Open an image you want to crop by choosing File | Open. Now, click on the Rectangle Select Tool from the main left toolbar, like so (click the image below to see a larger version):

Click and drag to select the area you want to crop to, or what you want the final image to look like. Let go of the click and you will see the dashed lines around the area. You can use the mouse, click and drag, to adjust these lines as needed. Just move your mouse to the edge of the dashed lines and the cursor will change to indicate you can drag and move the lines.

Here’s the important part – you have to invert the selection, so you can delete the area surrounding the final image you want. So, use the keyboard shortcut, CTRL-I (or you can select it off the menu by choosing Select | Invert) to invert the selection, so now you will have the area around the image crop you want selected. The dashed lines will now extend from the crop line to the edge of the image like this:

Next, we want to delete the now selected inverted area, so on the keyboard press CTRL-X to cut it away. I like to use Cut so I can undo if needed. Now you will have white space around the image crop:

Finally, to get rid of the white space and trim down to your cropped image, from the Image Menu (the menu right off the top of your image), choose Image | Autocrop Image

You will now have the picture cropped and can save accordingly.