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Today we do something a little more artistic, starting from a photo we extract the outline of subject and background, then we apply the random color to obtain a unique.

It is clear to everyone that this tutorial is not a photo, but a very strong image manipulation.

The following photo is our starting point, and the next arrival.

L'immagine originale

The original image

The final image changed

First, after opening the original photo we will make sure that the only colors are the white and the Black. Nothing grayscale, solo la black silhouette with white background. To do this go on “Colors” – “Threshold“, and apply the parameters in the figure.

This will be our partial result.

The two-color often tends to highlight the vignetting image (in this case visible in’in the top right corner). You can eliminate the effect of the instrument “Rubber after removed the “alpha channel” (“click with the right level” – “Remove Alpha Channel“).

It seems obvious that (being of only two colors) image not present antialiasing. We must now soften the edges, and to do that we will use Gaussian blur (“Filters” – “Blur” – “Gaussian“).

Now, to sharpen the contours, we will use the tool “Contrast” from the menu “Colors” – “Brightness contrast“.

And this will be our partial result.

Now that we have our silhouette color it randomly on the whole surface black, and to do that we will work to a new level on which will be the colors, then we will use the rendering engine of Gimp. “Filters” – “Render” – “Clouds” – “Plasma“.

When I use the tool “Plasma” I always prefer to leave the check mark “Randomize“, in this way it is difficult to have two equal in two different jobs.

At this point, to give a little’ of continuity to the color, we will act with the Gaussian blur with a radius quite high.

And now we are at the end. In the tab “Levels” we change the “Mode” the “Usual” a “Screen“.

Clearly with a different seed “Fortuity” filter “Plasma” get different colors. Here are some examples.


I keep this blog as a hobby by 2009. I am passionate about graphic, technology, software Open Source. Among my articles will be easy to find music, and some personal thoughts, but I prefer the direct line of the blog mainly to technology. For more information contact me.


TheJoe · 11 October 2011 at 7:13 PM

Thanks, Luigi. In fact, just do not know if the effect is replicated in Photoshop.

First, since there is no version for Linux, I do not have the option to install, secondly this blog is inspired by the open source movement, tutorials by me are collected and processed applicable (I can see giving it a quick read other articles) only to open source software. I have never written a line about closed source application, if not for comparing qualities and defects.

Forgive me for being too direct, but do not you think that a user willing to expend 1.450,79 EUR should at least have the skills necessary to achieve the desired effect from this tutorial?

louis · 11 October 2011 at 3:24 PM

Salve. Excellent effect! congratulations! but you can replicate on photoshop??there is the effect render – plasma….

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