This sample code creates a worksheet with chart and then Saves Excel chart as JPG. For more details refer to https://kb.aspose.com/cells/net/how-to-convert-excel-chart-to-jpg-in-csharp-without-interop/

Convert Excel Chart to JPG in CSharp without Interop.cs

using Aspose.Cells;
using Aspose.Cells.Charts;
using Aspose.Cells.Rendering;
namespace ConvertExcelChartToJPGInCSharpWithoutInterop
{
    class Program
    {
        static void Main(string[] args)
        {
            //Initialize the license object
            License license = new License();

            //Set license by providing path to license file
            license.SetLicense("Aspose.Cells.lic");

            //Initialize a workbook object
            Workbook ChartToImageWorkbook = new Workbook();

            //Get the first worksheet 
            Worksheet ChartWorksheet = ChartToImageWorkbook.Worksheets[0];

            //Insert sample data into worksheet
            ChartWorksheet.Cells[23, 2].PutValue(2014);
            ChartWorksheet.Cells[24, 2].PutValue(2015);
            ChartWorksheet.Cells[25, 2].PutValue(2016);
            ChartWorksheet.Cells[26, 2].PutValue(2017);
            ChartWorksheet.Cells[27, 2].PutValue(2018);
            ChartWorksheet.Cells[28, 2].PutValue(2019);
            ChartWorksheet.Cells[29, 2].PutValue(2020);

            ChartWorksheet.Cells[23, 3].PutValue(3);
            ChartWorksheet.Cells[24, 3].PutValue(4);
            ChartWorksheet.Cells[25, 3].PutValue(9);
            ChartWorksheet.Cells[26, 3].PutValue(13);
            ChartWorksheet.Cells[27, 3].PutValue(16);
            ChartWorksheet.Cells[28, 3].PutValue(3);
            ChartWorksheet.Cells[29, 3].PutValue(7);
            
            //Create a bar chart
            Chart chart = ChartWorksheet.Charts[ChartWorksheet.Charts.Add(ChartType.Bar , 1, 1, 22, 12)];

            //Add chart series and set its properties
            Series aSerie = chart.NSeries[chart.NSeries.Add("D24:D30", true)];
            chart.Title.Text = "Company Yearly Sales";
            aSerie.XValues = "C24:C30";
            aSerie.Name = "Sale in Millions";

            //Set image options 
            ImageOrPrintOptions imageOrPrintOptions = new ImageOrPrintOptions();
            imageOrPrintOptions.ImageType = Aspose.Cells.Drawing.ImageType.Jpeg;

            //Save the image as JPEG
            chart.ToImage("ExcelChartToJPG.jpg", imageOrPrintOptions);
        }
    }
}