IE9中的灰度

Question

我的画廊存在问题，我不知道如何解决这个问题。 我根据此网站建议（http://webdesignerwall.com/demo/html5-grayscale/）对我的照片使用灰度效果。在FF和Chrome中一切正常，但在IE中，所有图像都无法正确显示（重叠）。 / p>

我的代码是：

    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();
    }
                // Fade in images so there isn't a color "pop" document load and then on window load

    $(".item img").animate({opacity:1},0);

    // clone image
    $('a.thumb img').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(){
            var el = $(this);
            el.parent().css({"width":this.width,"height":this.height});
            el.dequeue();
        });
        this.src = grayscale(this.src);
    });

    // Fade image 
    $('a.thumb img').mouseover(function(){
        $(this).parent().find('img:first').stop().animate({opacity:1}, 0);
    })
    $('.img_grayscale').mouseout(function(){
        $(this).stop().animate({opacity:0}, 0);
    });

我还在IE9中附上了显示照片的图像（http://postimage.org/image/8w0hnqnbl/ 提前谢谢！