Worksheet to Image Conversion

27 Jul 20267 minutes to read

Assemblies Required

Refer to the following links for the assemblies and NuGet packages required to convert a worksheet to an image, per platform:

NOTE

Worksheet-to-image conversion can be performed by referring to the Syncfusion.XlsIORenderer.Net.Core NuGet package in UWP platform.

Convert as bitmap

The following code shows how to convert a specified range of rows and columns in the worksheet to a bitmap image. The four integer parameters are firstRow, firstColumn, lastRow, and lastColumn (1-based).

// The following snippet assumes `application` and `worksheet` are already initialized
// (see the "Complete code" tab below for the full setup).
// Initialize XlsIORenderer
application.XlsIORenderer = new XlsIORenderer();

// Create a new memory stream to save the image
using (Stream stream = new MemoryStream())
{
    // Convert worksheet to image and save it to the stream.
    worksheet.ConvertToImage(1, 1, 10, 20, stream);
}
// The following snippet assumes `sheet` is already initialized (see the
// "Complete code" tab below for the full setup).
// Convert as bitmap
Image image = sheet.ConvertToImage(1, 1, 10, 20);
image.Save("Sample.png", ImageFormat.Png);
'The following snippet assumes `sheet` is already initialized (see the
'"Complete code" tab below for the full setup).
'Convert as bitmap
Dim image As Image = sheet.ConvertToImage(1, 1, 10, 20)
image.Save("Sample.png", ImageFormat.Png)

Save as stream

The following code snippet shows how to save a sheet as a stream. On Windows, you can choose the output ImageType (such as Bitmap, Metafile, or EMF); on .NET Standard the format is controlled by ExportImageOptions (see the Customizing the output image section below). After ConvertToImage(...) writes to a stream, the stream’s position is at the end; set stream.Position = 0 if you need to read from it afterwards.

// The following snippet assumes `application` and `sheet` are already initialized
// (see the "Complete code" tab below for the full setup).
// Initialize XlsIORenderer
application.XlsIORenderer = new XlsIORenderer();

// Convert and save as a stream (default image format on cross-platform is PNG).
using (MemoryStream stream = new MemoryStream())
{
    sheet.ConvertToImage(1, 1, 10, 20, stream);
}
// Convert and save as a stream with a specific ImageType
using (MemoryStream stream = new MemoryStream())
{
    sheet.ConvertToImage(1, 1, 10, 20, ImageType.Metafile, stream);
}
'Convert and save as a stream with a specific ImageType
Using stream As MemoryStream = New MemoryStream()
    sheet.ConvertToImage(1, 1, 10, 20, ImageType.Metafile, stream)
End Using

The complete code snippet of the previous options is given below.

using (ExcelEngine excelEngine = new ExcelEngine())
{
	IApplication application = excelEngine.Excel;
	application.DefaultVersion = ExcelVersion.Xlsx;

	// Open the input workbook.
	using (FileStream inputStream = new FileStream(Path.GetFullPath(@"Data/InputTemplate.xlsx"), FileMode.Open, FileAccess.Read))
	{
		IWorkbook workbook = application.Workbooks.Open(inputStream);
		IWorksheet sheet = workbook.Worksheets[0];

		//Initialize XlsIORenderer
		application.XlsIORenderer = new XlsIORenderer();

		#region Save
		// Save the used range of the worksheet as a PNG image.
		using (FileStream outputStream = new FileStream(Path.GetFullPath("Output/Image.png"), FileMode.Create, FileAccess.Write))
		{
			sheet.ConvertToImage(sheet.UsedRange, outputStream);
		}
		#endregion
	}
}
using (ExcelEngine excelEngine = new ExcelEngine())
{
  IApplication application = excelEngine.Excel;
  application.DefaultVersion = ExcelVersion.Xlsx;
  IWorkbook workbook = application.Workbooks.Open("Sample.xlsx", ExcelOpenType.Automatic);
  IWorksheet sheet = workbook.Worksheets[0];

  // Convert the worksheet range to a bitmap image and save it as PNG.
  Image image = sheet.ConvertToImage(1, 1, 10, 20);
  image.Save("Sample.png", ImageFormat.Png);

  // Convert the worksheet range to a Metafile image and save it to a stream.
  using (MemoryStream stream = new MemoryStream())
  {
    sheet.ConvertToImage(1, 1, 10, 20, ImageType.Metafile, stream);
  }
}
Using excelEngine As ExcelEngine = New ExcelEngine()
  Dim application As IApplication = excelEngine.Excel
  application.DefaultVersion = ExcelVersion.Xlsx
  Dim workbook As IWorkbook = application.Workbooks.Open("Sample.xlsx", ExcelOpenType.Automatic)
  Dim sheet As IWorksheet = workbook.Worksheets(0)

  ' Convert the worksheet range to a bitmap image and save it as PNG.
  Dim image As Image = sheet.ConvertToImage(1, 1, 10, 20)
  image.Save("Sample.png", ImageFormat.Png)

  ' Convert the worksheet range to a Metafile image and save it to a stream.
  Using stream As MemoryStream = New MemoryStream()
    sheet.ConvertToImage(1, 1, 10, 20, ImageType.Metafile, stream)
  End Using
End Using

A complete working example to convert an Excel worksheet to an image in C# is present on this GitHub page.

NOTE

  1. Instance of XlsIORenderer class is mandatory to convert the worksheet to image using .NET Standard assemblies.
  2. In .NET Standard, the Image format and quality can be specified using the ExportImageOptions class. By default the ImageFormat is set to PNG and ScalingMode is set to Best.
  3. Worksheet to image conversion is supported from .NET Framework 2.0 and .NET Standard 1.4 onwards.

Non-Supported Features:

  • Subscript/Superscript
  • Shrink to fit
  • Complex conditional formatting

See also