GIMP Tutorial: Crop Circle Effect

Written by Marc Roberge | 19 January 2010

How To GIMP Crop Circle Effect

How to create a crop circle effect with GIMP.

We start by opening a suitable background image. As crop circles generally “appear” in farmers fields, we will be using this photo: field.

Open “field.jpg” in GIMP.

To create the “crop circle”, we want to use a black and white image or logo. Black and white ClipArt images work great. If you want to use something else, you will need to convert your image to black and white first and then with the Brightness/Contrast tool (Colors>Brightness-Contrast) you can try driving the brightness all the way down and the contrast all the way up. I will be using this image: linux.

We want to open this one as a layer. From the menu, select “File>Open As Layer…”

From the Layers panel, right-click your new layer and choose “Add Alpha Channel” from the menu.

From the toolbox, choose the “Select by color” tool. Click on the white portion of your image, because we want to keep the dark logo, and press your Delete key. Finally, press Ctrl+A to remove the selection.

Now, we need to adjust our logo perspective in order to match it to our perspective view of the field. As it is, our field handily has tractor lines which will help us align our logo. From the toolbox, choose the “Perspective” tool. Click the image once and use the corner handles to align the edges of your image to the tractor lines and click OK.

Now we need to create a copy of our logo. From the layers panel, click the “Duplicate Layer” button.

At this point, we will need to open our “Brightness-Contrast” tool (Colors>Brightness-contrast from the menu) and dial both brightness and contrast sliders all the way to the left. This will give us a gray copy of our logo.

Now we will nudge this gray layer over just a tad to create an outline with the underlying black logo. To do this, select the “Move” tool from the toolbox, click on the gray logo once and use your keyboard arrows to move the layer right and down like this:

Go to the layers panel and right-click on the top layer. Choose “Merge down” from the menu.

We are back down to 2 layers. Click the top layer to make sure it is selected and from the drop-down “Mode” menu, select “Overlay”.

In this final step, from the menu, select “Colors>Colorize”. Slide Hue and Saturation values all the way to the left and adjust “Lightness” only slightly to the left.