[Solved] Background image missing while exporting DIV to Image using html2canvas

hello

when i change background color to background image it does not export image kindly check the html

<div id="dvTable" style="width: 340px; background-image: url('https://image.freepik.com/free-photo/blue-denim-texture-background_87358-114.jpg') !important; padding: 5px">
    <u>Customer Records</u>
    <br />
    <br />
    <table cellspacing="0" rules="all" border="1" id="GridView1" style="border-collapse: collapse;">
        <tr>
            <th scope="col" style="width: 90px;">Customer Id
            </th>
            <th scope="col" style="width: 120px;">Name
            </th>
            <th scope="col" style="width: 120px;">Country
            </th>
        </tr>
        <tr>
            <td>1</td>
            <td>John Hammond</td>
            <td>United States</td>
        </tr>
        <tr>
            <td>2</td>
            <td>Mudassar Khan</td>
            <td>India</td>
        </tr>
        <tr>
            <td>3</td>
            <td>Suzanne Mathews</td>
            <td>France</td>
        </tr>
        <tr>
            <td>4</td>
            <td>Robert Schidner</td>
            <td>Russia</td>
        </tr>
    </table>
</div>
<br />
<asp:HiddenField ID="hfImageData" runat="server" />
<asp:Button ID="btnExport" Text="Export to Image" runat="server" UseSubmitBehavior="false"
    OnClick="ExportToImage" OnClientClick="return ConvertToImage(this)" />
<script type="text/javascript" src="https://ajax.googleapis.com/ajax/libs/jquery/1.8.3/jquery.min.js"></script>
<script type="text/javascript" src="https://cdnjs.cloudflare.com/ajax/libs/html2canvas/0.4.1/html2canvas.min.js"></script>
<script type="text/javascript">
    function ConvertToImage(btnExport) {
        html2canvas($('[id*=dvTable]')[0], {
            onrendered: function (canvas) {
                var base64 = canvas.toDataURL();
                $("[id*=hfImageData]").val(base64);
                __doPostBack(btnExport.name, "");
            }
        });
        return false;
    }
</script>