Sharpening & Smoothing refer to the digital manipulations
used to analyze values of pixels of similar color shades and applying
changes to these color shades. We can apply various filters to
directionally sharpen or soften images, to accentuate edge details
without affecting the rest of the image area, to highlight edges among
areas of different colors and shades, to enhance defined areas of an
image, to diffuse or smear colors to create a smooth appearance, to tone
down differences between adjacent pixels without loss of detail,
With sharpness adjustments, we can make blemishes disappear, soften
the midday sun on a baby's face, or freeze a "bullet-train".