In this article we'll cover some of the the most popular effects (I use most) for a variety of graphic works. Clearly this is a non-exhaustive list, filter after filter but perhaps we can do something interesting.

This list of filters just wants to be a overview of what you can easily do with Gimp.

1. Gaussian Blur

Filters – Blur – Gaussian Blur

A filter for simple if, and easy to understand. It is used and abused, thanks to this filter are possible multiple photographic manipulations that we see every day in magazines, on the tram or on billboards.

Can serve to change the depth of a photo:

In this photo the lawn has been blurred after

Or possess, joined to the mode “Luce forte” to add a glow that was not there before:

2. Disorder

Filters – Disorder – Chance

The Noise filter is very useful when we want to make a realistic picture, or maybe when necessary to operate on a photo quality is not excellent, making the work as realistic as possible.

3. Clouds

Filters – Render – Clouds – Solid Noise

It is a viable alternative “Filters” – “Render” – “Clouds” – “Fog”, using it with a metallic texture you can create the effect of smoke.

Here used in mode “Multiplier” background with a radial gradient with the center and red edges blacks.

4. Polar Coordinates

Filters – Distortions – Polar Coordinates

With the filter “Polar Coordinates” it is possible “iron” ideally a three-dimensional image, plane. Combining filters “Polar Coordinates” and “Wind”, starting from this:

We achieve this:

And with the mode “Burn” the end result is this:

5. Lens Flare

Filters – Luci ed ombre – Lens Flare

This filter can be lethal for those who are editing to make hasty. There is a risk that the result jobs are cheesy and unappealing.

I often use this filter with a black background mode “Fencing”, for example above the filter “Fog” we created earlier.

6. Sfocatura movement

Filters – Blur – Sfocatura movement

With the right coordinates, you can set an image so that the viewer feels catapulted into. A filter simple to use, but be careful not to abuse, after a while the door nausea.

7. Unsharp Mask

Filters – Improvement – Unsharp Mask

Another filter more than useful. Not having blurry photos (not because I do not ever came, but because I do not find) celebrate it as a sfocata. The filter “Unsharp Mask” enhances the edges of the photo, putting in better visibility the subject. I arrived at the final result starting from the blurry photo. Clearly the original photo was of much higher quality, but this seems like a good result.

The photos I downloaded

After the blur

After the "Unsharp Mask"

8. Mapping of polyhedron

Filters – Map – Map Object

With the mapping of object Gimp allows us to enter for a moment into the world of 3D. Its functions mapping and rendering 3d environment are very limited (Gimp is a raster image 2d), but it is possible, for example “map” an image to fit on to a plane, a sphere, a cube or a cylinder. Among other things, you can choose whether to give the new object a light, a directional light or no light.

The original

Mapping on the floor with light point in the lower left

Mapping to object sphere with the same point light

Mapping with cube object

Mapping to object cylinder

9. High Pass

Gimp Plugin Register

Another plugin is the plugin used and abused “High Pass”. It is usually used in conjunction with PhotoShop, but the operation is elementary, and developers must not have been difficult to create it for Gimp. Here you will find the plugin (to put in the plug-ins folder) Gimp, The following is a quick demonstration of what it does.

The original

After the High Pass

Changing the mode of this level is the result

For the curious here are explanation of one of the “guru” Gimp with the steps that led to the creation of the plugin.

10. Make Seamless

Filters – Map – Make Seamless

The last series filter allows the creation of so-called “pattern”, graphic elements which if repeated continuously give the illusion of infinity. Following the initial image:

The more observant will notice that the second picture has elements “overlapping”, if you want to do a job “up” you can correct these elements, but still alongside the image the eye is fooled in each case, as evidenced by the last image.

I wish you all good manipulations, obviously with Gimp.