User Guide
GNU Image Manipulation Program
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15.3.9.2 Options
Figure 15.35: Options of the ‘Border Average Filter’
Border Size You can set there the border Thickness in pixels.
Number of Colors The Bucket Size lets you control the number of colors considered as similar and counted with the same
‘bucket’. A low bucket size value (i.e. a high bucket number) gives you better precision in the calculation of the average
color. Note that better precision does not necessarily mean better results (see example below).
15.3.9.3 Examples illustrating the ‘Border Average’ filter
Figure 15.36: Original image
Original image: colors are pure Red (255;0;0), pure Blue (0;0;255), and different but similar kinds of Green
(00******;11******;00******).
Figure 15.37: ‘Number of Colors’ is set to 8:
The resulting color is a Red (254,2,2).
The most frequent color on the image border is pure Red (255,0,0). Since the bucket size is low, the different Green tones are
not recognized as the same color. The resulting color is a nearly pure Red (254,2,2) and becomes the foreground color of the
Toolbox.
Figure 15.38: ‘Number of Colors’ is set to 64:
The resulting color is Green (32,224,32).