How to Create a Thumbnail Using C#

Creating image thumbnails provides a visual representation or preview of an image, video, or webpage. Thumbnails are typically smaller in size and help users quickly understand the topic or essence of the content before jumping into it. Thumbnails grab attention and play a vital role in attracting visitors to your website. With Aspose.SVG for .NET API, you can programmatically create thumbnails quickly and efficiently!

C# code example to create a thumbnail

A thumbnail is a small picture that is a miniature version of a larger image. You can create an image thumbnail with a few lines of code:

Create a Thumbnail – C#

// Declare an SVG thumbnail generation function
SVGDocument CreateThumbnail(string imagePath, int width, int height)
    // Initialize a new instance of SVGDocument
    var document = new SVGDocument();

    // Create image element with specified size
    var image = (SVGImageElement)document.CreateElementNS("", "image");
    image.Href.BaseVal = imagePath;
    image.Width.BaseVal.Value = width;
    image.Height.BaseVal.Value = height;

    // Append the image element to the document

    return document;

// Define thumbnail parameters
string source = "";
int thumbnailWidth = 200;
int thumbnailHeight = 200;

// Create an svg thumbnail
using (var svg = CreateThumbnail(source, thumbnailWidth, thumbnailHeight))
    // 1) Save thumbnail to an SVG file

    // 2) Save thumbnail to an image file
    var options = new ImageRenderingOptions
        Format = ImageFormat.Png,
        PageSetup = { Sizing = SizingType.FitContent }
    using (var device = new ImageDevice(options, "image-thumbnail.png"))

Steps to Create a Thumbnail in C#

  1. Declare an SVG thumbnail generation function using CreateThumbnail().
  2. Initialize a new instance of the SVGDocument class.
  3. Use the CreateElementNS(namespaceURI, qualifiedName) method of the SVGDocument class to create an image instance.
  4. To add the <image> element to the document, use AppendChild() method.
  5. Define thumbnail parameters – image source, thumbnail width and height.
  6. Use the CreateThumbnail() method to create an SVG thumbnail and set the image’s attributes.
  7. Use one of the ImageRenderingOptions() constructor to initialize a new instance of the ImageRenderingOptions class. You can customize the rendering process by specifying the SizingType , image format, etc. PNG is used as the default image format.
  8. Create an instance of ImageDevice using the ImageDevice() constructor.
  9. Call the RenderTo(device) method to send the current document to the output rendering device.
  10. The image thumbnail will be saved into an image file on the specified path. Also, you can use Save() method to save the thumbnail as an SVG file.

Aspose.SVG C# library allows .NET developers to create thumbnails quickly and efficiently. The Aspose.Svg.Rendering.Image namespace provides specific device classes as well as a few rendering options classes responsible for rendering to raster formats: JPEG, PNG, BMP, GIF, and TIFF. Please visit our Documentation to learn more about using Aspose.SVG API functions.


1. What is a thumbnail in coding?

A thumbnail is a reduced-size representation of an image that allows users to quickly understand the topic or essence of the content before deciding to interact with the page and follow a link, which is why they play a vital role in bringing visitors to your site.

2. In what formats can the thumbnail creation result be saved?

Aspose.SVG allows you to create thumbnails from JPG, PNG, BMP, GIF, or TIFF images and save the result in the most common image formats such as JPG, PNG, BMP, GIF, TIFF, etc.

3. Why create a thumbnail for the Web?

Thumbnailing enhances visual presentation, provides information, draws attention, facilitates navigation, and optimizes content for different devices. Applying thumbnails helps users understand what they can expect and make informed choices about which content to explore. Additionally, thumbnails optimize loading times, ensuring a smoother browsing experience. By utilizing thumbnails, you can enhance your content’s visual appeal, organization, and discoverability.

4. How to create a thumbnail in C#?

You can use Aspose.SVG for .NET API and the provided C# code to programmatically create a thumbnail from an image. Copy the C# code and use it on your own application.

Get Started with .NET SVG API

If you are interested in developing scalable vector graphics and their application, install our flexible, high-speed Aspose.SVG for .NET API with a powerful set of interfaces for C# and other .NET programming languages.
Install from command line as nuget install Aspose.SVG or via Package Manager Console of Visual Studio with Install-Package Aspose.SVG. Alternatively, get the offline MSI installer or DLLs in a ZIP file from downloads. Aspose.SVG for .NET API is a standalone library and does not depend on any software for SVG document processing.
For more details about C# library installation and system requirements, please refer to Aspose.SVG Documentation.

Other Supported Aspose.SVG for .NET API Features

Use the Aspose.SVG C# library to convert, merge, edit SVG documents, convert color codes, vectorize images and more!