边缘检测的Canny算子与碰撞
上篇博文演示了下落的小球与WebCamera视频图像中边缘的碰撞效果，对于视频边缘的提取略显粗糙，使用Canny算子可以提取更为精细的边缘源代码：WebCamera_Canny
[code lang="as3"]
package{
import com.bit101.components.CheckBox;
import com.bit101.components.HUISlider;
import com.bit101.components.Panel;
import com.bit101.components.Style;
import com.coreyoneil.collision.CollisionList;
import com.quasimondo.bitmapdata.CameraBitmap;
import flash.display.Bitmap;
import flash.display.BitmapData;
import flash.display.Sprite;
import flash.display.StageAlign;
import flash.display.StageScaleMode;
import flash.events.Event;
import ru.inspirit.bitmapdata.CannyEdgeDetector;
[SWF(frameRate="31")]
public class WebCamera_Canny extends Sprite{
private var camera:CameraBitmap;
private var cannyBmpd:BitmapData;
private var cannyBmp:Bitmap;
private var cannyEdgeDetector:CannyEdgeDetector;
private var _bold:Boolean = false;
private var _binary:Boolean = true;
private var w:int = 400;
private var h:int = 300;
private var collisionList:CollisionList;
private var bubbles:Array;
private var gravity:Number = 1;
private var friction:Number = 0.95;
private var panel:Panel;
public function WebCamera_Canny(){
if(stage) init();
else addEventListener(Event.ADDED_TO_STAGE,init);
}
private function init(e:Event = null):void{
initStage();
camera = new CameraBitmap(w,h,25,true);
addChild(new Bitmap(camera.bitmapData));
camera.addEventListener(Event.RENDER,onRenderCamera);
cannyEdgeDetector = new CannyEdgeDetector(camera.bitmapData);
cannyEdgeDetector.lowThreshold = 0.03;
cannyEdgeDetector.highThreshold = 0.18;
cannyBmpd = new BitmapData(w,h,false,0);
cannyBmp = new Bitmap(cannyBmpd);
var refBmp:Bitmap = new Bitmap(cannyBmpd);
refBmp.x = w;
addChild(refBmp);
collisionList = new CollisionList(cannyBmp);
collisionList.excludeColor(0xff000000,255,0,0,0);
bubbles = new Array();
for(var i:int=0;i h){
bubble.y = 0;
bubble.vy = bubble.vx = 0;
bubble.x = Math.random() * w;
}
else if(bubble.x > w){
bubble.x = w - bubble.width/2;
bubble.vx *= -1;
}
else if(bubble.x < 0){
bubble.x = bubble.width/2;
bubble.vx *= -1;
}
}
}
private function initControls():void{
Style.PANEL = 0x333333;
Style.BUTTON_FACE = 0x333333;
Style.LABEL_TEXT = 0xF6F6F6;
panel = new Panel(this);
panel.width = w*2;
panel.height = 40;
panel.y = 300;
var slide:HUISlider = new HUISlider(panel, 90, 5, 'LOW THRESHOLD', onLowThresChange);
slide.setSliderParams(.01, .9, .03);
slide.labelPrecision = 3;
slide.width = 250;
slide = new HUISlider(panel, 90, 18, 'HIGH THRESHOLD', onHighThresChange);
slide.setSliderParams(.01, 1.0, .18);
slide.labelPrecision = 3;
slide.width = 250;
var checkbox:CheckBox = new CheckBox(panel, 350, 22, 'GET BOLD EDGES', onBoldChange);
checkbox.selected = false;
checkbox = new CheckBox(panel, 350, 9, 'NORMALIZE CONTRAST', onNormContrastChange);
checkbox.selected = false;
checkbox = new CheckBox(panel, 500, 9, 'BINARY IMAGE', onBinaryChange);
checkbox.selected = true;
}
private function onLowThresChange(e:Event):void{
cannyEdgeDetector.lowThreshold = HUISlider(e.currentTarget).value;
}
private function onHighThresChange(e:Event):void{
cannyEdgeDetector.highThreshold = HUISlider(e.currentTarget).value;
}
private function onBoldChange(e:Event):void{
_bold = CheckBox(e.currentTarget).selected;
}
private function onBinaryChange(e:Event):void{
_binary = CheckBox(e.currentTarget).selected;
}
private function onNormContrastChange(e:Event):void{
cannyEdgeDetector.doNormalizeContrast = CheckBox(e.currentTarget).selected;
}
}
}
[/code]
<img src="http://www.everyinch.net/wp-content/uploads/2011/10/WebCamera_Canny.jpg" alt="" title="WebCamera_Canny" width="798" height="339" class="aligncenter size-full wp-image-588" />