Fallback fonts in Word to Image conversion

17 Dec 202521 minutes to read

During Word to image conversions, if a glyph of the input text is unavailable in the specified font, the text will not be rendered properly. To address this, the Syncfusion^® Word (DocIO) library allows users to specify fallback fonts. When a glyph is missing, the library will use one of the fallback fonts to render the text correctly in the output image.

Users can configure fallback fonts in the following ways:

Initialize default fallback fonts.
Set custom fonts as fallback fonts for specific script types, including Arabic, Hebrew, Chinese, Japanese, and more.
Set custom fonts as fallback fonts for a particular range of Unicode text.

NOTE

DocIO internally uses user-initialized or specified fallback fonts for Unicode characters during Word to Image conversion. Therefore, the specified fallback fonts must be installed in the production environment or embedded in the input Word document (DOCX). Otherwise, it will not render the text properly using the fallback fonts.

Initialize default fallback fonts

The following code example demonstrates how to initialize a default fallback fonts while converting a Word document to an Image. The InitializeDefault API sets the default fallback fonts for specific script types like Arabic, Hebrew, Chinese, Japanese etc.

C# [Cross-platform]
//Opens the file as stream.
using (FileStream inputStream = new FileStream("Template.docx", FileMode.Open, FileAccess.Read))
{
   //Loads an existing Word document file stream.
   using (WordDocument wordDocument = new WordDocument(inputStream, Syncfusion.DocIO.FormatType.Docx))
   {
      //Initialize the default fallback fonts collection.
      wordDocument.FontSettings.FallbackFonts.InitializeDefault();
      //Instantiation of DocIORenderer for Word to image conversion.
      using (DocIORenderer render = new DocIORenderer())
      {
         //Convert the entire Word document to images.
         Stream[] imageStreams = wordDocument.RenderAsImages(); 
         int i = 0;
         foreach (Stream stream in imageStreams)
         {
             //Reset the stream position.
             stream.Position = 0;
             //Save the stream as file.
             using (FileStream fileStreamOutput = File.Create("WordToImage_" + i + ".jpeg"))
             {
                stream.CopyTo(fileStreamOutput);
             }
             i++;
         }
      }
   }
}

You can download a complete working sample from GitHub.

Fallback fonts based on script type

The following code example demonstrates how a user can add fallback fonts based on the script types, which DocIO considers internally when converting a Word document to an Image.

C# [Cross-platform]
//Opens the file as stream.
using (FileStream inputStream = new FileStream("Template.docx", FileMode.Open, FileAccess.Read))
{
   //Loads an existing Word document file stream.
   using (WordDocument wordDocument = new WordDocument(inputStream, Syncfusion.DocIO.FormatType.Docx))
   {
      //Adds fallback font for "Arabic" script type.
      wordDocument.FontSettings.FallbackFonts.Add(ScriptType.Arabic, "Arial, Times New Roman");
      //Adds fallback font for "Hebrew" script type.
      wordDocument.FontSettings.FallbackFonts.Add(ScriptType.Hebrew, "Arial, Courier New");
      //Adds fallback font for "Hindi" script type.
      wordDocument.FontSettings.FallbackFonts.Add(ScriptType.Hindi, "Mangal, Nirmala UI");
      //Adds fallback font for "Chinese" script type.
      wordDocument.FontSettings.FallbackFonts.Add(ScriptType.Chinese, "DengXian, MingLiU");
      //Adds fallback font for "Japanese" script type.
      wordDocument.FontSettings.FallbackFonts.Add(ScriptType.Japanese, "Yu Mincho, MS Mincho");
      //Adds fallback font for "Thai" script type.
      wordDocument.FontSettings.FallbackFonts.Add(ScriptType.Thai, "Tahoma, Microsoft Sans Serif");
      //Adds fallback font for "Korean" script type.
      wordDocument.FontSettings.FallbackFonts.Add(ScriptType.Korean, "Malgun Gothic, Batang");
      //Instantiation of DocIORenderer for Word to image conversion.
      using (DocIORenderer render = new DocIORenderer())
      {
         //Convert the entire Word document to images.
         Stream[] imageStreams = wordDocument.RenderAsImages(); 
         int i = 0;
         foreach (Stream stream in imageStreams)
         {
             //Reset the stream position.
             stream.Position = 0;
             //Save the stream as file.
             using (FileStream fileStreamOutput = File.Create("WordToImage_" + i + ".jpeg"))
             {
                 stream.CopyTo(fileStreamOutput);
             }
             i++;
         }
      }
   }
}

You can download a complete working sample from GitHub.

Fallback fonts for symbols

The following code example demonstrates how a user can add fallback fonts for Symbols and Emojis, which DocIO considers internally when converting a Word document to image.

C# [Cross-platform]
//Opens the file as stream.
using (FileStream inputStream = new FileStream("Template.docx", FileMode.Open, FileAccess.Read))
{
   //Loads an existing Word document file stream.
   using (WordDocument wordDocument = new WordDocument(inputStream, Syncfusion.DocIO.FormatType.Docx))
   {
      //Adds fallback font for basic symbols like bullet characters.
      wordDocument.FontSettings.FallbackFonts.Add(ScriptType.Symbols, "Segoe UI Symbol, Arial Unicode MS, Wingdings");
      //Adds fallback font for mathematics symbols.
      wordDocument.FontSettings.FallbackFonts.Add(ScriptType.Mathematics, "Cambria Math, Noto Sans Math, Segoe UI Symbol, Arial Unicode MS");
      //Adds fallback font for emojis.
      wordDocument.FontSettings.FallbackFonts.Add(ScriptType.Emoji, "Segoe UI Emoji, Noto Color Emoji, Arial Unicode MS");   
      //Instantiation of DocIORenderer for Word to image conversion.
      using (DocIORenderer render = new DocIORenderer())
      {
         //Convert the entire Word document to images.
         Stream[] imageStreams = wordDocument.RenderAsImages(); 
         int i = 0;
         foreach (Stream stream in imageStreams)
         {
             //Reset the stream position.
             stream.Position = 0;
             //Save the stream as file.
             using (FileStream fileStreamOutput = File.Create("WordToImage_" + i + ".jpeg"))
             {
                 stream.CopyTo(fileStreamOutput);
             }
             i++;
         }
      }
   }
}

You can download a complete working sample from GitHub

Fallback fonts for range of Unicode text

Users can set fallback fonts for specific Unicode range of text to be used in Word to Image conversion.

The following code example demonstrates how users can add fallback fonts by using a specific Unicode range of text that DocIO considers internally while converting a Word document to an image.

C# [Cross-platform]
//Opens the file as stream.
using (FileStream inputStream = new FileStream("Template.docx", FileMode.Open, FileAccess.Read))
{
   //Loads an existing Word document file stream.
   using (WordDocument wordDocument = new WordDocument(inputStream, Syncfusion.DocIO.FormatType.Docx))
   {
      //Adds fallback font for "Arabic" specific unicode range.
      wordDocument.FontSettings.FallbackFonts.Add(new FallbackFont(0x0600, 0x06ff, "Arial"));
      //Adds fallback font for "Hebrew" specific unicode range.
      wordDocument.FontSettings.FallbackFonts.Add(new FallbackFont(0x0590, 0x05ff, "Times New Roman"));
      //Adds fallback font for "Hindi" specific unicode range.
      wordDocument.FontSettings.FallbackFonts.Add(new FallbackFont(0x0900, 0x097F, "Nirmala UI"));
      //Adds fallback font for "Chinese" specific unicode range.
      wordDocument.FontSettings.FallbackFonts.Add(new FallbackFont(0x4E00, 0x9FFF, "DengXian"));
      //Adds fallback font for "Japanese" specific unicode range.
      wordDocument.FontSettings.FallbackFonts.Add(new FallbackFont(0x3040, 0x309F, "MS Gothic"));
      //Adds fallback font for "Thai" specific unicode range.
      wordDocument.FontSettings.FallbackFonts.Add(new FallbackFont(0x0E00, 0x0E7F, "Tahoma"));
      //Adds fallback font for "Korean" specific unicode range.
      wordDocument.FontSettings.FallbackFonts.Add(new FallbackFont(0xAC00, 0xD7A3, "Malgun Gothic"));
      //Instantiation of DocIORenderer for Word to Image conversion.
      using (DocIORenderer render = new DocIORenderer())
      {
         //Convert the entire Word document to images.
         Stream[] imageStreams = wordDocument.RenderAsImages(); 
         int i = 0;
         foreach (Stream stream in imageStreams)
         {
             //Reset the stream position.
             stream.Position = 0;
             //Save the stream as file.
             using (FileStream fileStreamOutput = File.Create("WordToImage_" + i + ".jpeg"))
             {
                 stream.CopyTo(fileStreamOutput);
             }
             i++;
         }
      }
   }
}

You can download a complete working sample from GitHub.

Modify the exiting fallback fonts

The following code example demonstrates how user can modify or customize the existing fallback fonts using FontNames API while converting a Word document to an Image.

C# [Cross-platform]
//Opens the file as stream.
using (FileStream inputStream = new FileStream("Template.docx", FileMode.Open, FileAccess.Read))
{
   //Loads an existing Word document file stream.
   using (WordDocument wordDocument = new WordDocument(inputStream, Syncfusion.DocIO.FormatType.Docx))
   {
      //Initialize the default fallback fonts collection.
      wordDocument.FontSettings.FallbackFonts.InitializeDefault();
      FallbackFonts fallbackFonts = wordDocument.FontSettings.FallbackFonts;
      foreach (FallbackFont fallbackFont in fallbackFonts) 
      {
         //Customize a default fallback font name as "David" for the Hebrew script.
         if (fallbackFont.ScriptType == ScriptType.Hebrew)
            fallbackFont.FontNames = "David";
         //Customize a default fallback font name as "Microsoft Sans Serif" for the Thai script.
         else if (fallbackFont.ScriptType == ScriptType.Thai)
            fallbackFont.FontNames = "Microsoft Sans Serif";
      }
      //Instantiation of DocIORenderer for Word to Image conversion.
      using (DocIORenderer render = new DocIORenderer())
      {
         //Convert the entire Word document to images.
         Stream[] imageStreams = wordDocument.RenderAsImages(); 
         int i = 0;
         foreach (Stream stream in imageStreams)
         {
             //Reset the stream position.
             stream.Position = 0;
             //Save the stream as file.
             using (FileStream fileStreamOutput = File.Create("WordToImage_" + i + ".jpeg"))
             {
                 stream.CopyTo(fileStreamOutput);
             }
             i++;
         }
      }
   }
}

You can download a complete working sample from GitHub.

Supported script types

The following table illustrates the supported script types by the .NET Word library (DocIO) in Word to Image conversion.

Script types	Ranges	Default fallback fonts considered in InitializeDefault() API
Arabic	0x0600 - 0x06ff 0x0750 - 0x077f 0x08a0 - 0x08ff 0xfb50 - 0xfdff 0xfe70 - 0xfeff	Arial, Times New Roman, Microsoft Uighur
Hebrew	0x0590 - 0x05ff 0xfb1d - 0xfb4f	Arial, Times New Roman, David
Hindi	0x0900 - 0x097F 0xa8e0 - 0xa8ff 0x1cd0 - 0x1cff	Mangal, Utsaah
Chinese	0x4E00 - 0x9FFF 0x3400 - 0x4DBF 0xd840 - 0xd869 0xdc00 - 0xdedf 0xA960 - 0xA97F 0xFF00 - 0xFFEF 0x3000 - 0x303F	DengXian, MingLiU, MS Gothic
Japanese	0x30A0 - 0x30FF 0x3040 - 0x309F	Yu Mincho, MS Mincho
Thai	0x0E00 - 0x0E7F	Tahoma, Microsoft Sans Serif
Korean	0xAC00 - 0xD7A3 0x1100 - 0x11FF 0x3130 - 0x318F 0xA960 - 0xA97F 0xD7B0 - 0xD7FF 0xAC00 - 0xD7AF	Malgun Gothic, Batang
Tamil	0x0B80 - 0x0BFF	Latha, Nirmala UI, Arial Unicode MS
Bengali	0x0980 - 0x09FF	Vrinda, Arial Unicode MS, Nikosh, Siyam Rupali, Nirmala UI
Gujarati	0x0A80 - 0x0AFF	Shruti, Nirmala UI, Arial Unicode MS
Telugu	0x0C00 - 0x0C7F	Gautami, Nirmala UI, Arial Unicode MS
Malayalam	0x0D00 - 0x0D7F	Kartika, Nirmala UI, Arial Unicode MS
Kannada	0x0C80 - 0x0CFF	Tunga, Nirmala UI, Arial Unicode MS
Ethiopic	0x1200 - 0x137F 0x1380 - 0x139F	Nyala, Ebrima
Khmer	0x1780 - 0x17FF 0x19E0 - 0x19FF	MoolBoran, DaunPenh, Leelawadee, Leelawadee UI
Gurmukhi	0x0A00 - 0x0A7F	Raavi, Nirmala UI, Arial Unicode MS
Canadian	0x1400 - 0x167F	Euphemia, Gadugi
Cherokee	0x13A0 - 0x13FF 0xAB70 - 0xABBF	Plantagenet Cherokee, Gadugi, Arial Unicode MS
Yi	0xA000 - 0xA48F 0xA490 - 0xA4CF	Microsoft Yi Baiti, Arial Unicode MS
Tibetan	0x0F00 - 0x0FFF	Microsoft Himalaya, Nirmala UI, Arial Unicode MS
Thaana	0x0780 - 0x07BF	MV Boli, Nirmala UI, Arial Unicode MS
Syriac	0x0700 - 0x074F	Estrangelo Edessa, Segoe UI Historic, Arial Unicode MS
Odia	0x0B00 - 0x0B7F	Kalinga, Nirmala UI, Arial Unicode MS
Lao	0x0E80 - 0x0EFF	DokChampa, Lao UI, Leelawadee UI, Arial Unicode MS
Sinhala	0x0D80 - 0x0DFF	Iskoola Pota, Nirmala UI, Arial Unicode MS
Mongolian	0x1800 - 0x18AF	Mongolian Baiti, Microsoft YaHei, Arial Unicode MS
Vietnamese	0x00C0 - 0x00FF 0x0102 - 0x0103 0x0110 - 0x0111 0x0128 - 0x0129 0x0168 - 0x0169 0x01A0 - 0x01A1 0x01AF - 0x01B0 0x0300 - 0x036F	Times New Roman, Arial, Tahoma, Arial Unicode MS
Georgian	0x10A0 - 0x10FF 0x2D00 - 0x2D2F	Sylfaen, Arial Unicode MS
Armenian	0x0530 - 0x058F 0xFB13 - 0xFB17	Arial, Sylfaen, Arial Unicode MS
Buginese	0x1A00 - 0x1A1F	Leelawadee UI, Segoe UI Symbol
Bopomofo	0x3100 - 0x312F 0x31A0 - 0x31BF	Microsoft JhengHei, PMingLiU, SimSun, Arial Unicode MS
Javanese	0xA980 - 0xA9DF	Javanese Text, Segoe UI Symbol
Lisu	0xA4D0 - 0xA4FF	Segoe UI Symbol, Arial Unicode MS
Burmese	0x1000 - 0x109F 0xAA60 - 0xAA7F	Myanmar Text, Noto Sans Myanmar, Padauk
NKo	0x07C0 - 0x07FF	Ebrima, Arial Unicode MS
OlChiki	0x1C50 - 0x1C7F	Nirmala UI, Arial Unicode MS
Osmanya	0x10480 - 0x104AF	Ebrima, Noto Sans Osmanya
PhagsPa	0xA840 - 0xA87F	Phagspa, Microsoft PhagsPa, Noto Sans PhagsPa, Arial Unicode MS
SoraSompeng	0x110D0 - 0x110FF	Nirmala UI, Arial Unicode MS
TaiLe	0x1950 - 0x197F	Microsoft Tai Le, Arial Unicode MS
NewTaiLue	0x1980 - 0x19DF	Microsoft New Tai Lue, Arial Unicode MS
Tifinagh	0x2D30 - 0x2D7F	Ebrima, Arial Unicode MS
Symbols	0x2000 - 0x27BF 0x2300 - 0x23FF 0xF000 - 0xF104	Segoe UI Symbol, Arial Unicode MS, Wingdings
Mathematics	0x2200 - 0x2AFF 0x1D400 - 0x1D7FF	Cambria Math, Noto Sans Math, Segoe UI Symbol, Arial Unicode MS
Emoji	0x1F300 - 0x1FAFF 0xFE0F - 0xFE0F	Segoe UI Emoji, Noto Color Emoji, Arial Unicode MS

NOTE

In Azure Web Service and Azure APP Service, .NET GDI+ (System.Drawing) does not support the Metafile image (vector image). So, the image will be generated as Bitmap (raster image).

Creating an instance of the ChartToImageConverter class is mandatory to convert the charts present in the Word document to Image. Otherwise, the charts are not preserved in the generated image.

Total number of images may vary based on unsupported elements in the input Word document.

Word to Image conversion has the same limitations and unsupported elements of Word to PDF conversion.

Different styles of borders are known limitations in Word to Image conversion in ASP.NET Core, Xamarin, Blazor, WinUI, and .NET MAUI platforms.

In ASP.NET Core, Blazor, Xamarin, WinUI and .NET MAUI platforms, to convert Word document to images we recommend you to use Word to image assemblies or NuGet as a reference in your application.

DocIO supports Word to image conversion in UWP application using DocIORenderer.

In addition to the previous NuGet packages, we recommend to use SkiaSharp.NativeAssets.Linux v3.119.1 and HarfBuzzSharp.NativeAssets.Linux v8.3.1.2 NuGets to perform Word to Image conversion in Linux environment.

The .NET Word Library (DocIO) uses System.Drawing functionalities for Word to image conversion in .NET Framework applications. And System.Drawing itself uses a fallback font to preserve the Unicode text while drawing the text in the image. So, these Fallback fonts APIs are not supported in .NET Framework.

Search docs

Ask HelpBot

Search docs

Ask HelpBot

Fallback fonts in Word to Image conversion

Initialize default fallback fonts

Fallback fonts based on script type

Fallback fonts for symbols

Fallback fonts for range of Unicode text

Modify the exiting fallback fonts

Supported script types