Simply defined, Fractal Interpolation, also referred to as Fractals, uses a method to closely match the edges of each pixel to the one closest to it, so that the integrity of the pixel is changed just enough to keep the blurred look at bay.

Using the free software offered by GIMP, available for download here:

https://www.google.com/webhp?sourceid=chrome-instant&rlz=1C1CHFX_enUS604US604&ion=1&espv=2&ie=UTF-8#q=gimp%20download

Open the image you want to resize in Gimp. Simply go to Image » Scale Image. Enter your desired dimensions. Under the Quality section choose Sinc (Lanczos3) as Interpolation method and click on the Scale Image button.