Do it with the GIMPBasic Areal EffectsBlurDemo of a simple blur

4.1.2. Demo of a simple blur

Demo

  1. Open lena.png.
  2. Select <Image> Filters Generic "Convolution Matrix..."
  3. Set the 9 middle squares to 1, the other squares to 0 and the divisor to 9.
    (What we are doing is replacing every pixel with the average of its 3*3 neighbourhood.)
  4. Press the "OK" button.
  5. Repeat several times with Ctrl+F (or <Image> Filters "Repeat Last" ) to strengthen the effect.

Written by Shlomi Fish