Render EBooks as HTML, PDF, and image files

GroupDocs.Viewer for Python via .NET allows you to render your EBooks (EPUB, MOBI) in HTML, PDF, PNG, and JPEG formats. You do not need to use any book reader to load and view EBooks within your .NET application (web or desktop).

To start using the GroupDocs.Viewer API, create a Viewer class instance. Pass a book you want to view to the class constructor. You can load the book from a file or stream. Call one of the Viewer.view method overloads to convert the EBook to HTML, PDF, or image format.

View EBookd online View demos and examples on GitHub

Supported EBooks file formats

GroupDocs.Viewer supports the following EBooks file formats:

GroupDocs.Viewer can detect the book format automatically based on information in the file header.

Render EBooks as HTML

Create an HtmlViewOptions class instance and pass it to the Viewer.View method to convert an EBook file to HTML. The HtmlViewOptions class properties allow you to control the conversion process. For instance, you can embed all external resources in the generated HTML file, minify the output file, and optimize it for printing. Refer to the following documentation section for details: Rendering to HTML.

Create an HTML file with embedded resources

To save all elements of an HTML page (including text, graphics, and stylesheets) into a single file, call the HtmlViewOptions.for_embedded_resources method and specify the output file name.

with gv.Viewer("abook.epub") as viewer:
    # Create an HTML file for each document page.
    # {0} is replaced with the current page number in the file name.
    viewOptions = gvo.HtmlViewOptions.for_embedded_resources("page_{0}.html")
    viewer.view(viewOptions)

The following image demonstrates the result:

Render an EBook to HTML

Create an HTML file with external resources

If you want to store an HTML file and additional resource files (such as fonts, images, and stylesheets) separately, call the HtmlViewOptions.for_external_resources method and pass the following parameters:

  • The output file path format
  • The path format for the folder with external resources
  • The resource URL format
with gv.Viewer("abook.epub") as viewer:
    # Create an HTML file for each document page.
    # Specify the HTML file names and location of external resources.
    # {0} and {1} are replaced with the current page number and resource name, respectively.
    viewOptions = gvo.HtmlViewOptions.for_external_resources("page_{0}.html", "page_{0}/resource_{0}_{1}", "page_{0}/resource_{0}_{1}")
    viewer.view(viewOptions)

The image below demonstrates the result. External resources are placed in a separate folder.

Place HTML resources in a separate folder

Render EBooks as PDF

Create a PdfViewOptions class instance and pass it to the Viewer.view method to convert an EBook to PDF. The PdfViewOptions class properties allow you to control the conversion process. For instance, you can protect the output PDF file, reorder its pages, and specify the quality of document images. Refer to the following documentation section for details: Rendering to PDF.

with gv.Viewer("abook.epub") as viewer:
    # Create a PDF file for the document.
    # Specify the PDF file name.
    viewOptions = gvo.PdfViewOptions("output.pdf")
    viewer.view(viewOptions)

The following image demonstrates the result:

Render an EBook to PDF

Render EBooks as PNG

Create a PngViewOptions class instance and pass it to the Viewer.view method to convert an EBook to PNG. Use the PngViewOptions.height and PngViewOptions.width properties to specify the output image size in pixels.

with gv.Viewer("abook.epub") as viewer:
    # Create a PNG image for each document page.
    # {0} is replaced with the current page number in the image name.
    viewOptions = gvo.PngViewOptions("output_{0}.png")
    # Set width and height.
    viewOptions.width = 800
    viewOptions.height = 900
    viewer.view(viewOptions)
The following image demonstrates the result:

Render an EBook to PNG

Render EBooks as JPEG

Create a JpgViewOptions class instance and pass it to the Viewer.view method to convert an EBook to JPEG. Use the JpgViewOptions.height and JpgViewOptions.width properties to specify the output image size in pixels.

with gv.Viewer("abook.epub") as viewer:
    # Create a JPEG image for each document page.
    # {0} is replaced with the current page number in the image name.
    viewOptions = gvo.JpgViewOptions("output_{0}.jpg")
    # Set width and height.
    viewOptions.width = 800
    viewOptions.height = 900
    viewer.view(viewOptions)