The Blur filter produces an effect similar to that of an out of focus camera shot. To produce this blur effect, the filter takes the average of the present pixel value and the value of adjacent pixels and sets the present pixel to that average value. All pixels of the active layer or selection are not concerned by blurring. For each pixel, a random number is generated based on the seed value and compared against the randomization percentage. If the random value is less than the randomization percentage, then the pixel is blurred. A 100% randomization, blurs all the pixels and blurred pixel number is at the most equal to randomization percentage.
Random Seed controls the randomization element of the blur. The button will set the seed using the hardware clock of the computer. Using is the preferred method for initializing Blur as it will provide a higher chance of differing values over many uses.
The Randomization slider represents the percentage of pixels of the active layer or selection which may be blurred. Higher value result in more blurring.
The Repeat slider represents the number of times the active layer will be blurred. Higher values result in more blurring.