Tutorial: highpass filter con Gimp
Today we talk about “Highpass filter“, a technique widely used in modern advertising to make “soft” images.
Obviously for all the work will adopt Gimp as a program for image manipulation.
This tutorial applies to entities, faces, views and, as we shall see, is perhaps the most widely used technique in magazines advertising.
In this tutorial we work on a subject. The image comes from Flickr.
First, after you open the image in Gimp duplicate the layer “Background”.
We apply the Gaussian blur the first level “Filters” – “Blur” – “Gaussian“, I have set a radius of 7 pixel.
At this point invert the colors level “Colors” – “Invert“, appear as a negative image.
Now, tab from the levels, reduce the opacity the 50% to get our highpass.
At this point duplicate the first level (should still call “Background“) and We merge the two layers that make up the highpass: one with a negative blurred and the new copy of the background. Change the mode level just coined in “Grain Extract” with opacity 50% and the job is finished.
Obviously with a radius of blur you would get even softer contours, it all depends (always eats) from what we want to achieve.