var imgBicubicInterpolation = new Class({

	initialize: function(elements){
		var _this=this;
		$$(elements).each(function(el) {
			if(el.get('tag') === "img" && !el.retrieve('bicubized')) {
				var src = el.src;
				if(src.split('.').pop()!='svg'){
					var imgW = el.width;
					var imgH = el.height;
					var can=new Element('canvas',{width:imgW,height:imgH}).setStyle('display','none').inject(el,'after');
					var callback = _this.drawHighResolutionImgThumbnail;
					_this.drawCanvas(can, imgW*8, imgH*8, src, callback, el, true);
				}
			}
		});
		
	},
    
	drawCanvas: function (can, imgW, imgH, src, callback, imgEl, crossOrigin) {
		var ctx = can.getContext('2d');
		var img = new Image();
		if(crossOrigin) {
		    img.setAttribute('crossOrigin', 'anonymous'); //tainted canvases may not be exported chrome, ie will also throw security error
		}
		
		var w = imgW;
		var h = imgH;

		img.onload = function() {
			
			// Step it down several times
			var can2 = document.createElement('canvas');
			can2.width = w;
			can2.height =h;
			var ctx2 = can2.getContext('2d');
			
			// Draw it at 1/2 size 3 times (step down three times)
			ctx2.drawImage(img, 0, 0, w/2, h/2);
			ctx2.drawImage(can2, 0, 0, w/2, h/2, 0, 0, w/4, h/4);
			ctx2.drawImage(can2, 0, 0, w/4, h/4, 0, 0, w/8, h/8);
			
			//ctx.drawImage(img, 0, 0, w/6, h/6);
			
			ctx.drawImage(can2, 0, 0, w/8, h/8, 0, 0, w/8, h/8);
			if(callback) {
				callback(can, this.src, imgEl);
				can.destroy();
			}
		};
	
		img.src = src;
	},
	
	drawHighResolutionImgThumbnail: function (can, attrSrc, imgEl) {
		$(imgEl).setProperty('src', can.toDataURL("image/png"));
		$(imgEl).setProperty('data-src', attrSrc);
		$(imgEl).store('bicubized',true);
	}

});