public SoftenPortraitEffect (int softness = 5, int lighting = 0, int warmth = 10)
{
if (softness < 0 || softness > 10)
throw new ArgumentOutOfRangeException ("softness");
if (lighting < -20 || lighting > 20)
throw new ArgumentOutOfRangeException ("lighting");
if (warmth < 0 || warmth > 20)
throw new ArgumentOutOfRangeException ("warmth");
this.softness = softness;
this.lighting = lighting;
this.warmth = warmth;
blur_effect = new GaussianBlurEffect (2);
bac_adjustment = new BrightnessContrastEffect (0, 0);
desaturate_op = new DesaturateOp ();
overlay_op = new OverlayBlendOp ();
}