Tento filtr rozšiřuje a zvýrazňuje světlé oblasti aktivní vrstvy nebo výběru.
For every image pixel, it brings the pixel Value (luminosity) into line with the upper value (the brightest) of the 8 neighboring pixels (3×3 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 pixelated.
On a solid background, this filter can delete noise: