如何使画布图像透明？

Question

I have used following code for creating a canvas image, but its not transparent. please let me know how can I get a transparent image

function capture(){
    $('#target').html2canvas({ 
        onrendered:function(canvas) {
            $('#img_val').val(canvas.toDataURL("image/png"));
            document.getElementById("myForm").submit();
        }
    });
}

Answer 1

Please try this for transparent image use CSS background color

function capture()
    {
    html2canvas($("#target"), {
            onrendered: function(canvas) {
                $('#img_val').val(canvas.toDataURL("image/png"));
                document.getElementById("myForm").submit();
            }
        });

Click [link] ( http://html2canvas.hertzen.com/documentation.html )