How to export the chart as an image (PNG format) without displaying UI?

<input type="button" value="PNG" onclick="chartPng()" />

<ej-chart id="container" enable-canvas-rendering="true">

</ej-chart>

<script>

//To call export method and settings

    function chartPng(sender) {

        var chart = $("#container").ejChart("instance"),

         exporting = chart.model.exportSettings;

        exporting.fileName = "chart";

        exporting.angle = 0;

        exporting.action = "Home/ExportChart";

        type = "png";

        exporting.mode = "server";

        chart.export();

    }

</script>

// To specify corresponding folder

static string path = "D:\\";

// To export chart image in specified folder

public void ExportChart(string Data, string ChartModel)

        {

            ChartProperties obj = ConvertChartObject(ChartModel);

            string type = obj.ExportSettings.Type.ToString().ToLower();

            string fileName = obj.ExportSettings.FileName;

            string orientation = obj.ExportSettings.Orientation.ToString();

            Data = Data.Remove(0, Data.IndexOf(',') + 1);

            MemoryStream stream = new MemoryStream(Convert.FromBase64String(Data));

            using (FileStream fs = new FileStream(path + "CoreChart.png", FileMode.Create))

            {

                using (BinaryWriter bw = new BinaryWriter(fs))

                {

                    byte[] data = Convert.FromBase64String(Data);

                    bw.Write(data);

                    bw.Dispose();

                }

            }

        }

// To create chart properties

        private ChartProperties ConvertChartObject(string ChartModel)

        {

            var settings = new JsonSerializerSettings

            {

                NullValueHandling = NullValueHandling.Ignore,

                MissingMemberHandling = MissingMemberHandling.Ignore

            };

            ChartProperties chartProp = new ChartProperties();

            chartProp = JsonConvert.DeserializeObject<ChartProperties>(ChartModel, settings);

            return chartProp;

        }