Tag Archives: thumb

Resize an image and make a thumb !

Hey !
After two months without any article, I’m ready to start again activity on this blog ! For sure, it’s the start of the new school year !

So today, a little script really useful to make a thumb in ActionScript 3 !
EDIT : deleted my previous script, this one coming from Cult Creative is awesome :

/**
* fitImage
* @ARG_object   the display object to work with
* @ARG_width    width of the box to fit the image into
* @ARG_height   height of the box to fit the image into
* @ARG_center   should it offset to center the result in the box
* @ARG_fillBox  should it fill the box, may crop the image (true), or fit the whole image within the bounds (false)
**/
 
private function fitImageProportionally( ARG_object:DisplayObject, ARG_width:Number, ARG_height:Number, ARG_center:Boolean = true, ARG_fillBox:Boolean = true ):Bitmap {
 
    var tempW:Number = ARG_object.width;
    var tempH:Number = ARG_object.height;
 
    ARG_object.width = ARG_width;
    ARG_object.height = ARG_height;
 
    var scale:Number = (ARG_fillBox) ? Math.max(ARG_object.scaleX, ARG_object.scaleY) : Math.min(ARG_object.scaleX, ARG_object.scaleY);
 
    ARG_object.width = tempW;
    ARG_object.height = tempH;
 
    var scaleBmpd:BitmapData = new BitmapData(ARG_object.width * scale, ARG_object.height * scale);
    var scaledBitmap:Bitmap = new Bitmap(scaleBmpd, PixelSnapping.ALWAYS, true);
    var scaleMatrix:Matrix = new Matrix();
    scaleMatrix.scale(scale, scale);
    scaleBmpd.draw( ARG_object, scaleMatrix );
 
    if (scaledBitmap.width > ARG_width || scaledBitmap.height > ARG_height) {
 
        var cropMatrix:Matrix = new Matrix();
        var cropArea:Rectangle = new Rectangle(0, 0, ARG_width, ARG_height);
 
        var croppedBmpd:BitmapData = new BitmapData(ARG_width, ARG_height);
        var croppedBitmap:Bitmap = new Bitmap(croppedBmpd, PixelSnapping.ALWAYS, true);
 
        if (ARG_center) {
            var offsetX:Number = Math.abs((ARG_width -scaleBmpd.width) / 2);
            var offsetY:Number = Math.abs((ARG_height - scaleBmpd.height) / 2);
 
            cropMatrix.translate(-offsetX, -offsetY);
        }
 
        croppedBmpd.draw( scaledBitmap, cropMatrix, null, null, cropArea, true );
        return croppedBitmap;
 
    } else {
        return scaledBitmap;
    }
 
}

An other method coming from Thibault Imbert !

package {
 
	import flash.display.BitmapData;
	import flash.geom.ColorTransform;
	import flash.geom.Matrix;
 
	/**
	 * @author Maxime Cousinou
	 */
	public class BitmapManager {
 
		public static function reduceBitmapData(bmp:BitmapData, ratio:Number, transparent:Boolean = true):BitmapData {
 
			var bmpData:BitmapData = new BitmapData(Math.round(bmp.width * ratio), Math.round(bmp.height * ratio), transparent, 0x00FFFFFF);
			var scaleMatrix:Matrix = new Matrix(bmpData.width / bmp.width, 0, 0, bmpData.height / bmp.height, 0, 0);
			bmpData.draw(bmp, scaleMatrix);
 
			return bmpData;
		}
 
		public static function resizeBitmapData(bmp:BitmapData, ratio:Number, transparent:Boolean = true):BitmapData {
 
			var bmpData:BitmapData = new BitmapData(Math.round(bmp.width * ratio), Math.round(bmp.height * ratio), transparent, 0x00FFFFFF);
			var scaleMatrix:Matrix = new Matrix(bmpData.width / bmp.width, 0, 0, bmpData.height / bmp.height, 0, 0);
			var colorTransform:ColorTransform = new ColorTransform();
			bmpData.draw(bmp, scaleMatrix, colorTransform, null, null, true);
 
			return bmpData;
		}
 
		public static function resampleBitmapData(bmp:BitmapData, ratio:Number, transparent:Boolean = true):BitmapData {
 
			if (ratio >= 1) {
				return BitmapManager.resizeBitmapData(bmp, ratio, transparent);
			} else {
				var bmpData:BitmapData = bmp.clone();
				var appliedRatio:Number = 1;
 
				do {
					if (ratio < 0.5 * appliedRatio) {
						bmpData = BitmapManager.resizeBitmapData(bmpData, 0.5, transparent);
						appliedRatio = 0.5 * appliedRatio;
					} else {
						bmpData = BitmapManager.resizeBitmapData(bmpData, ratio / appliedRatio, transparent);
						appliedRatio = ratio;
					}
				} while (appliedRatio != ratio);
 
				return bmpData;
			}
		}
	}
}