Computes a edge-enhanced image by convolving with a sharpening kernel.
The sharpening kernel is based upon the circular kernel used in
BlurImg, but with different weights. The weight for all "count" of the
kernel elements inside the circle is -Sharpen, except for the center,
which gets a weight of
1 + Sharpen * (count - 1)
so that the weights sum to unity. Sharpen must lie in the range
[0..1]. This edge detection method is described in:
Digital Image Processing, Gonzales, R.C., Wintz, P.,
Addison Wesley, Second Edition, 1987, pp 176--186.
Port: Img In
Port: Img Out
© The Numerical Algorithms Group Ltd, Oxford UK. 2000