Blur filter takes every pixel and set his new color as average of colors around a certain radius. With ranges below youcan modify the radius length.

Since RGB is a space stored as square root of the brightness of each channel, the average should be calculated as average of squares. The linear average slightly darkens the image and the edges, but is more rapid than the real average. The various blurs here proposed are in couple: first the quadratic average (*q.a.*), second the linear average (*l.a.*).

For clarity, the blur title (constant, linear...) refers to the weight applied to the pixels around the radius. For example, the constant blur applies a coefficient *1.0* to all the pixel in the circle, when the quadratic one applies *-d/(R ^{2}+1)+1 >= 0* (where

*This alghoritm is really performance hitting, you are warned!*

Image:

Constant blur (sharp edges)

Blur ^{(q.a.)} > Time:

Blur ^{(l.a.)} > Time:

Circular blur (a bit softened edges)

Blur ^{(q.a.)} > Time:

Blur ^{(l.a.)} > Time:

Inverse Quadratic blur (soft effect)

Blur ^{(q.a.)} > Time:

Blur ^{(l.a.)} > Time:

Linear blur (very soft effect)

Blur ^{(q.a.)} > Time:

Blur ^{(l.a.)} > Time: