image - 下采样位图图像像素 actionscript 3？

Question

我需要将图像中的像素从 480 X 480 减少到 30 X 30。这需要对像素进行下采样，我没有看到任何删除位图图像中单个像素的方法。

我需要这种下采样，因为我正在研究图像处理中的失真 - 简而言之。

对此的任何帮助将不胜感激。

Answer 1

package
{
    import flash.display.Bitmap;
    import flash.display.BitmapData;
    import flash.display.Loader;
    import flash.display.Sprite;
    import flash.events.Event;
    import flash.geom.Matrix;
    import flash.net.URLRequest;

    public class DownSampling extends Sprite
    {
        private var _loader : Loader;
        public function DownSampling()
        {
            _loader = new Loader;
            _loader.contentLoaderInfo.addEventListener(Event.COMPLETE, onImgLoaded);

            // Get the bitmap
            _loader.load(new URLRequest("https://appharbor.com/assets/images/stackoverflow-logo.png"));
        }

        private function onImgLoaded(e : Event) : void
        {
            var currentBitmapdata : BitmapData = Bitmap(_loader.content).bitmapData;
            var i : uint = 9;
            var downFactor : Number = 0.2;

            // this will reduce size by 20%
            var downMat : Matrix = new Matrix;
            downMat.scale(1 - downFactor, 1 - downFactor);

            while(--i)
            {
                // Create new bitmapdata but smaller
                var smallerImg : BitmapData = new BitmapData(currentBitmapdata.width * (1-downFactor), currentBitmapdata.height * (1-downFactor), true, 0);

                // Copy and apply scale
                smallerImg.draw(currentBitmapdata, downMat);

                // Add to stage and set alpha to 50%
                addChild(new Bitmap(smallerImg)).alpha = .5;

                // Apply the same transform next loop
                currentBitmapdata = smallerImg;
            }
        }

    }
}

结果 ：