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Sharpness
We define sharpness as the difference of brightness (the pixel's L
component in HSL color space) from a pixel to its neighboring pixels.
Sharpness for each pixel is calculated based on the values of immediately surrounding it pixels, only the luma component L
is used for this calculation.
A pixel's new value is calculated based on the simple matrix (see below) with a little twist: the central coefficient of 5 is adjusted based on the new value of sharpness as follows: coef_5 = 5 + sharpness
, where sharpness
is in range [-1..+1]
.
0 | -1 | 0 |
-1 | coef_5 | -1 |
0 | -1 | 0 |