root/as3/Study/BilateralFilter/BilateralFilter.as

/**
* ...
* @author Default
* @version 0.1
*/

package {
        import flash.display.BitmapData;
        import flash.geom.Rectangle;
        
        public class BilateralFilter {
                public function BilateralFilter() {
                }
                
                public static const SIGMA_R:Number = 0.0425;
                public var cx:int = 5;
                public var cy:int = 5;
                
                public function filter1(src:BitmapData, x:int, y:int):uint {
                        var fo:Number = Number(src.getPixel(x, y) & 0xFF) / 255;;
                        var ue:Number = 0;
                        var shita:Number = 0;
                        var sigma_d:Number = 0.01;
                        var sigma_r:Number = SIGMA_R;
                        var dx:Number = 1.0 / src.width;
                        
                        for (var v:int = -cy; v <= cy; ++v) {
                                for (var u:int = -cx; u <= cx; ++u) {
                                        var f:Number = Number(src.getPixel(x + u, y + v) & 0xFF) / 255;
                                        var ww:Number = get_w(fo, f);
                                        var e:Number = get_e(u, v);
                                        ue += e * ww * f * dx;
                                        shita += e * ww * dx;
                                }
                        }
                        
                        var ups:int = (int)(ue / shita * 255);
                        if (ups < 0) ups = 0;
                        else if (ups > 255) ups = 255;
                        return ups | (ups << 8) | (ups << 16);
                }
                
                public function filter(bd:BitmapData):BitmapData {
                        var w:int = bd.width;
                        var h:int = bd.height;
                        var out:BitmapData = new BitmapData(w, h);
                        
                        bd.lock();
                        out.lock();
                        for (var y:int = 0; y < h; ++y) {
                                for (var x:int = 0; x < w; ++x) {
                                        out.setPixel(x, y, filter1(bd, x, y));
                                }
                        }
                        bd.unlock();
                        out.unlock();
                        
                        return out;
                }
                
                public function get_w(fo:Number, f:Number):Number {
                        return Math.exp(-0.5 * (fo - f) * (fo - f) / (SIGMA_R * SIGMA_R));
                }
                
                public function get_e(u:int, v:int):Number {
                        return Math.exp(-0.5 * (u * u + v * v) / (cx * cy));
                }
        }
}