How can I export an excel worksheet as image?

I'm triying to generate an image from an excel worksheet. After a lot of research, I'm using the following code, but at some point I get an exception:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using Microsoft.Office.Interop.Excel;

namespace ConsoleApplication1
{
    class Prueba
    {
        [STAThread]
        static void Main(string[] args)
        {
            var a = new Microsoft.Office.Interop.Excel.Application();

            try
            {
                Workbook w = a.Workbooks.Open(@"C:\SCRATCH\Libro2.xlsx");
                Worksheet ws = w.Sheets["Report"];
                ws.Protect(Contents: false);
                Range r = ws.Range["B2:H20"];
                r.CopyPicture(XlPictureAppearance.xlScreen, XlCopyPictureFormat.xlBitmap);
                a.DisplayAlerts = false;

                // System.Runtime.InteropServices.COMException Excepción de HRESULT: 0x80010105 (RPC_E_SERVERFAULT)
                ChartObject chartObj = ws.ChartObjects().Add(r.Left, r.Top, r.Width, r.Height); 

                chartObj.Activate();
                Chart chart = chartObj.Chart;
                chart.Paste();
                chart.Export(@"C:\SCRATCH\image.JPG", "JPG");
                chartObj.Delete();
                w.Close(SaveChanges: false);
            } 
            finally
            {
                a.Quit();                
            }

        }
    }
}

I'm using Office 2013, 64 bits, Windows 7 64 and .Net 4.5.

This worked for me in a WinForms project:

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using Excel = Microsoft.Office.Interop.Excel;
using ios = System.Runtime.InteropServices;

namespace ClipBoardTest
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        public void ExportRangeAsJpg()
        {
            Excel.Application xl;

            xl = (Excel.Application)ios.Marshal.GetActiveObject("Excel.Application");

            if (xl == null)
            {
                MessageBox.Show("No Excel !!");
                return;
            }

            Excel.Workbook wb = xl.ActiveWorkbook;
            Excel.Range r = wb.ActiveSheet.Range["A1:E10"];
            r.CopyPicture(Excel.XlPictureAppearance.xlScreen,
                           Excel.XlCopyPictureFormat.xlBitmap);

             if (Clipboard.GetDataObject() != null)
            {
                IDataObject data = Clipboard.GetDataObject();

                if (data.GetDataPresent(DataFormats.Bitmap))
                {
                    Image image = (Image)data.GetData(DataFormats.Bitmap, true);
                    this.pict1.Image = image;
                    image.Save(@"C:\_Stuff\test\sample.jpg",
                        System.Drawing.Imaging.ImageFormat.Jpeg);
                }
                else
                {
                    MessageBox.Show("No image in Clipboard !!");
                }
            }
            else
            {
                MessageBox.Show("Clipboard Empty !!");
            }  
        }

        private void button1_Click(object sender, EventArgs e)
        {
            ExportRangeAsJpg();
        }



    }
}

For a console app you need to see also: http://blog.another-d-mention.ro/programming/c/use-clipboard-copypaste-in-c-console-application/