Sharpen a Bitmap

This is an implementation of the unsharp masking method to sharpen an image.

The mathematical equation is

sharpened = original + (original-blurred(sigma))*weight

where the blurring is done using a Gaussian Blur with a given sigma in terms of pixels. The picture is from the wikipedia page.

Use the side panel to tweak the sigma and the weight. Drag the red line to see immediate result of the tweak.