This filter widens and enhances bright areas of the active layer or
selection.
For every image pixel, it brings the pixel Value (luminosity) into line
with the upper value (the brightest) of the 8 neighbouring pixels (3x3
matrix). So, a bright pixel is added around bright areas. An isolated
pixel on a brighter background will be deleted. A larger bright area
will dilate by one pixel in all directions.
On complex images, bright areas are widened and enhanced the same, and
somewhat pixellated.
On a solid background, this filter can delete noise:
