1.) User uploads photo (JPG, GIF, etc.)
2.) User is returned a manipulated photo
Manipulated photo should look exactly like the default 'Threshold' option in Photoshop (Image - Adjustments - Threshold..), which is _roughly_ equivilent to Decreasing the colors to 2 colors, black and white, with no diffusion - resulting in a kind of black and white sketch drawn look.