// On window load. This waits until images have loaded which is essential
$(window).load(function(){
	if ($.browser.webkit || ($.browser.mozilla && $.browser.version.slice(0,3) >= "1.9") || ($.browser.msie && $.browser.version.slice(0,3) >= "8.0")) {
		// Fade in images so there isn't a color "pop" document load and then on window load
		$("img.grayscale").fadeIn(500);
	
		// clone image
		$('img.grayscale').each(function(){
			var el = $(this);
			//el.css({"position":"absolute"}).wrap("<div class='img_wrapper' style='display: inline-block'>").clone().addClass('img_grayscale').css({"position":"absolute","z-index":"998","opacity":"0"}).insertBefore(el).queue(function(){
			el.wrap("<div class='img_wrapper' style='display: inline-block'>").clone().addClass('img_grayscale').css({"position":"absolute","z-index":"998","opacity":"0"}).insertBefore(el).queue(function(){
				var el = $(this);
				el.parent().css({"width":this.width,"height":this.height});
				el.dequeue();
			});
			this.src = grayscale(this.src);
		});
	
		// Fade image
		$('img.grayscale').mouseover(function(){
			$(this).parent().find('img:first').stop().animate({opacity:1}, 1000);
		})
		$('.img_grayscale').mouseout(function(){
			$(this).stop().animate({opacity:0}, 1000);
		});
	}
});

// Grayscale w canvas method
function grayscale(src){
	var canvas = document.createElement('canvas');
	var ctx = canvas.getContext('2d');
	var imgObj = new Image();
	imgObj.src = src;
	canvas.width = imgObj.width;
	canvas.height = imgObj.height;
	ctx.drawImage(imgObj, 0, 0);
	var imgPixels = ctx.getImageData(0, 0, canvas.width, canvas.height);
	for(var y = 0; y < imgPixels.height; y++){
		for(var x = 0; x < imgPixels.width; x++){
			var i = (y * 4) * imgPixels.width + x * 4;
			var avg = (imgPixels.data[i] + imgPixels.data[i + 1] + imgPixels.data[i + 2]) / 3;
			imgPixels.data[i] = avg;
			imgPixels.data[i + 1] = avg;
			imgPixels.data[i + 2] = avg;
		}
	}
	ctx.putImageData(imgPixels, 0, 0, 0, 0, imgPixels.width, imgPixels.height);
	return canvas.toDataURL();
}