Does bitmapdata.copyPixels reduce image quality? - actionscript-3

Question

I am using a pair of classes to process and use Sprite Sheets but i have a slight problem, in comparison to the Bitmap class my SpriteSheetClips look very ugly, I scale both, Bitmap and SpriteSheetClip up and down using exactly the same image loaded and they look very different Bitmap looks smooth and nice while my SpriteSheetClips look pixelated with white borders, what is wrong with my classes that is causing this problem?
SpriteSheet (contains the cut bitmapDatas to be used for the clip):
package src {
import flash.display.BitmapData;
import flash.geom.Rectangle;
import flash.geom.Point;
public class SpriteSheet {
private var frames:Array = new Array();
public function SpriteSheet(spriteSheet:BitmapData, spriteSheetXML:XML)
{
var tileAmount:int = spriteSheetXML.SubTexture.length();
var rect:Rectangle;
var point:Point = new Point(0, 0);
var frame:BitmapData;
for (var a:int = 0; a < tileAmount ; a++)
{
frame = new BitmapData(spriteSheetXML.SubTexture[a].#width, spriteSheetXML.SubTexture[a].#height);
rect = new Rectangle(spriteSheetXML.SubTexture[a].#x, spriteSheetXML.SubTexture[a].#y, spriteSheetXML.SubTexture[a].#width, spriteSheetXML.SubTexture[a].#height);
frame.copyPixels(spriteSheet, rect, point);
frames.push(frame);
}
}
public function getTile(tileNum:int):BitmapData
{
return frames[tileNum-1];
}
public function get length():int
{
return frames.length;
}
}
}
SpriteSheetClip:
package src {
import flash.display.Sprite;
import flash.display.Bitmap;
import flash.events.Event;
public class SpriteSheetClip extends Sprite{
private var spriteSheet:SpriteSheet;
public var frame:Bitmap;
private var _currentFrame:int = 1;
private var _isPlaying:Boolean = true;
public var isLooping:Boolean = true;
private var frames:Array = new Array();
public function SpriteSheetClip(spriteSheetUsed:SpriteSheet)
{
spriteSheet = spriteSheetUsed;
frame = new Bitmap(spriteSheet.getTile(1), "auto", true);
this.addChild(frame);
for (var a:int = 0; a < totalFrames; a++)
{
frames.push({labelName:"", action:""});
}
this.addEventListener(Event.ENTER_FRAME, onFrameLoop, false, 0, true);
}
public function get currentFrame():int
{
return _currentFrame;
}
public function get totalFrames():int
{
return spriteSheet.length;
}
public function get isPlaying():Boolean
{
return _isPlaying;
}
public function start()
{
_isPlaying = true;
}
public function stop()
{
_isPlaying = false;
}
public function addFrameLabel(frameNum:int, labelName:String)
{
if (frameNum == 0)
{
return;
}
frames[frameNum-1].frameLabel = labelName;
}
public function addConnection(frameLabel:*, connectedFrameLabel:*)
{
var frameNum:int = frameNumber(frameLabel);
if (frameNum == 0)
{
return;
}
frames[frameNum-1].action = connectedFrameLabel;
}
private function frameNumber(frameLabel:*):int
{
if (int(frameLabel) <= totalFrames && int(frameLabel) > 0)
{
return int(frameLabel);
}
for (var a:int = 0; a < frames.length; a++)
{
if (frames[a].frameLabel == frameLabel)
{
return (a+1);
}
}
return 0;
}
public function gotoAndStop(frameLabel:*)
{
var frameNum:int = frameNumber(frameLabel);
if (frameNum > 0 && frameNum <= totalFrames)
{
_currentFrame = frameNum;
}
updateFrame();
stop();
}
public function gotoAndPlay(frameLabel:*)
{
var frameNum:int = frameNumber(frameLabel);
if (frameNum > 0 && frameNum <= totalFrames)
{
_currentFrame = frameNum;
}
updateFrame();
start();
}
private function updateFrame()
{
frame.bitmapData = spriteSheet.getTile(currentFrame);
}
public function nextFrame()
{
frame.bitmapData = spriteSheet.getTile(currentFrame);
if (frames[currentFrame-1].action != "")
{
this.gotoAndPlay(frames[currentFrame-1].action);
return;
}
_currentFrame++;
if (currentFrame > totalFrames)
{
if (isLooping)
{
_currentFrame = 1;
}
else
{
_currentFrame = totalFrames;
_isPlaying = false;
}
}
}
private function onFrameLoop(e:Event)
{
if (isPlaying)
{
nextFrame();
}
}
}
}