About Syncfusion .NET Excel to Image Conversion

30 Aug 202614 minutes to read

To quickly start converting an Excel document to an image, see this short video: Convert an Excel worksheet to an image with XlsIO.

IMPORTANT: Before running the samples on this page, install the required NuGet package for your target platform and register your Syncfusion license key. For more information, see the Licensing overview.

Assemblies Required

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

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).

C# [Cross-platform]
C# [Windows-specific]
VB.NET [Windows-specific]
// 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
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.

C# [Cross-platform]
C# [Windows-specific]
VB.NET [Windows-specific]
// 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
using (MemoryStream stream = new MemoryStream())
{
    sheet.ConvertToImage(1, 1, 10, 20, stream);
    // stream.Position = 0; // reset before reading, if needed
}
// 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.

C# [Cross-platform]
C# [Windows-specific]
VB.NET [Windows-specific]
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 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 Excel worksheet to image in C# is present on this GitHub page.

Instance of XlsIORenderer class is mandatory to convert the worksheet to image using .NET Standard assemblies.

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.

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

Register custom fonts

The .NET Excel library allows TrueType (.ttf) and OpenType (.otf) font files to be registered as custom fonts. The registered fonts are used during Excel-to-Image conversion when the required fonts are not installed on the system.

The following code example shows how to register custom fonts and use them during Excel-to-Image conversion.

C# [Cross-platform]
C# [Windows-specific]
VB.NET [Windows-specific]
// Create a collection to store the custom font streams
List<Stream> fontStreams = new List<Stream>();

// Retrieve all font files from the specified directory
foreach (string file in Directory.GetFiles(Path.GetFullPath(@"Data/MyFonts")))
{
    string extension = Path.GetExtension(file);

    // Load only TrueType and OpenType font files
    if (extension.Equals(".ttf", StringComparison.OrdinalIgnoreCase) ||
        extension.Equals(".otf", StringComparison.OrdinalIgnoreCase))
    {
        // Read the font file and copy its content to a memory stream
        FileStream fileStream = new FileStream(file, FileMode.OpenOrCreate, FileAccess.Read);
        Stream stream = new MemoryStream();
        fileStream.CopyTo(stream);
        stream.Position = 0;
        fontStreams.Add(stream);
    }
}

// Register the custom fonts for use during Excel-to-Image conversion
FontManager.RegisterFonts(fontStreams);

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

    IWorkbook workbook = application.Workbooks.Open(Path.GetFullPath(@"Data/Input.xlsx"));
    IWorksheet sheet = workbook.Worksheets[0];

    application.XlsIORenderer = new XlsIORenderer();

    using (FileStream outputStream = new FileStream(Path.GetFullPath("Output/Image.png"), FileMode.Create, FileAccess.Write))
    {
        sheet.ConvertToImage(sheet.UsedRange, outputStream);
    }
}

// Clear the registered fonts and dispose their associated streams
FontManager.ClearRegisteredFonts(true);
// Create a collection to store the custom font streams
List<Stream> fontStreams = new List<Stream>();

// Retrieve all font files from the specified directory
foreach (string file in Directory.GetFiles(Path.GetFullPath(@"Data/MyFonts")))
{
    string extension = Path.GetExtension(file);

    // Load only TrueType and OpenType font files
    if (extension.Equals(".ttf", StringComparison.OrdinalIgnoreCase) ||
        extension.Equals(".otf", StringComparison.OrdinalIgnoreCase))
    {
        // Read the font file and copy its content to a memory stream
        FileStream fileStream = new FileStream(file, FileMode.OpenOrCreate, FileAccess.Read);
        Stream stream = new MemoryStream();
        fileStream.CopyTo(stream);
        stream.Position = 0;
        fontStreams.Add(stream);
    }
}

// Register the custom fonts for use during Excel-to-Image conversion
FontManager.RegisterFonts(fontStreams);

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

    IWorkbook workbook = application.Workbooks.Open(Path.GetFullPath("Data/Input.xlsx"));

    IWorksheet worksheet = workbook.Worksheets[0];

    // Convert the specified Excel range to an image
    Image image = worksheet.ConvertToImage(1, 1, 20, 7);
        
    image.Save(Path.GetFullPath("Output/Sample.jpeg"),ImageFormat.Jpeg);
        
    workbook.Close();
}

// Clear the registered fonts and dispose their associated streams
FontManager.ClearRegisteredFonts(true);
' Create a collection to store the custom font streams
Dim fontStreams As New List(Of Stream)()

' Retrieve all font files from the specified directory
For Each file As String In Directory.GetFiles(Path.GetFullPath("Data/MyFonts"))

    Dim extension As String = Path.GetExtension(file)

    ' Load only TrueType and OpenType font files.
    If extension.Equals(".ttf", StringComparison.OrdinalIgnoreCase) OrElse
extension.Equals(".otf", StringComparison.OrdinalIgnoreCase) Then

        ' Read the font file and copy its content to a memory stream
        Dim fileStream As New FileStream(file, FileMode.OpenOrCreate, FileAccess.Read)

        Dim stream As Stream = New MemoryStream()
        fileStream.CopyTo(stream)
        stream.Position = 0
        fontStreams.Add(stream)

        fileStream.Dispose()
    End If
Next

' Register the custom fonts for use during Excel-to-image conversion
FontManager.RegisterFonts(fontStreams)

Using excelEngine As New ExcelEngine()
    Dim application As IApplication = excelEngine.Excel
    application.DefaultVersion = ExcelVersion.Xlsx

    Dim workbook As IWorkbook = application.Workbooks.Open(Path.GetFullPath("Data/Input.xlsx"))

    Dim worksheet As IWorksheet = workbook.Worksheets(0)

    ' Convert the specified Excel range to an image
    Dim image As Image = worksheet.ConvertToImage(1, 1, 20, 7)

    ' Save the converted image in JPEG format
    image.Save(Path.GetFullPath("Output/Sample.jpeg"), ImageFormat.Jpeg)

    workbook.Close()
End Using

' Clear the registered fonts and dispose their associated streams
FontManager.ClearRegisteredFonts(True)

A complete working example of registering custom fonts in C# is present on this GitHub page.

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