CHAPTER 9 HOW SOFTWARE CHANGES PIXELS BY THE NUMBERS^149
Instead, blur functions calculate a
weightedaverage of neighboring
pixels that looks something like this.
The color of the pixel being consid-
ered (center) carries the most weight
in the averaging process.(^4) Pixels directly adjacent are
weighted less, and the weighting
falls off drastically after that.
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Different types of blur functions use different numbers to calculate the color value
of the pixels, or widen or narrow the radius of pixels being used. Some blur
functions use this method to change every pixel in the image, while others will
not make changes at perceived edges.
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