Boo, the sharpest dog in the world !

I do not like Matlab's unsharp filter. Aside from the fact that the name is stupid, this filter overshoots the edges.

Here is today's fun assignment: design a filter using linear combination of derivatives of the image that does not overshoot.

Here is the output where I sharpen Boo, without overshooting him.

Boo, the sharpest dog in the world

Compare the above image with the original below. There is a subtle change in the image, which I personally believe makes it pleasing to look at.

Original Boo