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GroupDocs.Viewer for Python allows you to render your PDF files in HTML, PNG, and JPEG formats. Use this library to implement a simple PDF viewer within your Python application (web or desktop).

Create a Viewer class instance to get started with the GroupDocs.Viewer API. Pass a document you want to view to the class constructor. You can load the document from a file or stream. Call one of the Viewer.view method overloads to convert the document to HTML or image format. These methods allow you to render the entire document or specific pages.

View PDF files online View demos and examples on GitHub

GroupDocs.Viewer supports the following PDF and Page Layout file formats:

• Portable Document Format (.PDF)
• Microsoft XML Paper Specification (.XPS)
• Open XML Paper Specification (.OXPS)
• LaTeX Source Document (.TEX)

Create an HtmlViewOptions class instance and pass it to the Viewer.view method to convert a PDF 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.

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("resume.pdf") as viewer:
    # Create an HTML files.
    # {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:

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("resume.pdf") as viewer:
    # Create an HTML file for each PDF 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.

By default, PDF and EPUB documents are rendered to HTML with fixed layout to ensure that the output HTML looks the same as a source document. Rendering to fixed layout means that all the HTML elements are absolutely positioned to the container element. And container element has a fixed size so browser window resizing will not have an effect on the position and size of elements in a document.

The following image demonstrates PDF document rendered HTML with fixed layout:

The HtmlviewOptions.pdf_options.image_quality methods allows you to specify the quality of images in the output HTML file. You can set this property to one of the following values:

• ImageQuality.LOW — The image resolution is low (96 DPI), and the image size is small. Use this value to increase the conversion performance.
• ImageQuality.MEDIUM — The image resolution is medium (192 DPI), and the image size is larger compared to the low quality images.
• ImageQuality.HIGH — The image resolution is high (300 DPI), and the image size is big. Use of this value may decrease the conversion performance.

The following code snippet shows how to set the medium image quality when rendering a PDF document to HTML:

with gv.Viewer("resume.pdf") as viewer:
    # Create an HTML files.
    # {0} is replaced with the current page number in the file name.
    viewOptions = gvo.HtmlViewOptions.for_embedded_resources("page_{0}.html")
    # Set image quality to medium.
    viewOptions.pdf_options.image_quality = gvo.ImageQuality.MEDIUM 
    viewer.view(viewOptions)

GroupDocs.Viewer supports the HtmlViewOptions.pdf_options.render_text_as_image option that allows you to render text as an image when you convert a PDF file to HTML. In this case, the layout of the output HTML file closely mirrors the layout of the source PDF document.

The following code snippet shows how to enable this option in code:

with gv.Viewer("resume.pdf") as viewer:
    # Create an HTML files.
    # {0} is replaced with the current page number in the file name.
    viewOptions = gvo.HtmlViewOptions.for_embedded_resources("text-as-image_{0}.html")
    # Enable rendering text as image.
    viewOptions.pdf_options.image_quality = gvo.ImageQuality.MEDIUM 
    viewOptions.pdf_options.render_text_as_image = True
    viewer.view(viewOptions)

The image below illustrates the result. PDF content is exported to HTML as an image, so users cannot select or copy document text.

When you convert a PDF file to HTML, GroupDocs.Viewer creates an HTML document with a single layer (the z-index is not specified for document elements). This helps increase performance and reduce the output file size. If you convert a PDF document with multiple layers and want to improve the position of document elements in the output HTML file, use the HtmlViewOptions.pdf_options.enable_layered_rendering method to render text and graphics in the HTML file according to their z-order in the source PDF document.

The following code snippet shows how to enable the multi-layer rendering:

with gv.Viewer("resume.pdf") as viewer:
    # Create an HTML files.
    # {0} is replaced with the current page number in the file name.
    viewOptions = gvo.HtmlViewOptions.for_embedded_resources("page_{0}.html")
    # Enable the multi-layer rendering.
    viewOptions.pdf_options.enable_layered_rendering = True
    viewer.view(viewOptions)

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

with gv.Viewer("resume.pdf") as viewer:
    # Create a PNG image for each PDF page.
    # {0} is replaced with the current page number in the image name.
    viewOptions = gvo.HtmlViewOptions("output_{0}.png")
    # Set width and height.
    viewOptions.width = 950
    viewOptions.height = 550
    viewer.view(viewOptions)

The following image demonstrates the result:

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

with gv.Viewer("resume.pdf") as viewer:
    # Create a JPG image for each PDF 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 = 950
    viewOptions.height = 550
    viewer.view(viewOptions)

When you render PDF documents as images, GroupDocs.Viewer calculates the optimal image size to achieve better rendering quality. If you want the generated images to be the same size as pages in the source PDF document, use the PdfOptions.render_original_page_size method of the PngViewOptions or JpgViewOptions class (depending on the output image format).

with gv.Viewer("resume.pdf") as viewer:
    # Create a PNG image for each PDF page.
    # {0} is replaced with the current page number in the image name.
    viewOptions = gvo.PngViewOptions("output_{0}.png")
    # Preserve the size of document pages.
    viewOptions.pdf_options.render_original_page_size = True
    viewer.view(viewOptions)

To adjust the display of outline fonts when you convert PDF documents to PNG or JPEG, use the PdfOptions.enable_font_hinting method, as shown below:

with gv.Viewer("resume.pdf") as viewer:
    # Create a PNG image for each PDF page.
    # {0} is replaced with the current page number in the image name.
    viewOptions = gvo.PngViewOptions("output_{0}.png")
    # Enable font hinting
    viewOptions.pdf_options.enable_font_hinting = True
    viewer.view(viewOptions)

Refer to the following article for more information on font hinting: Font hinting.

When you render PDF files in other formats, GroupDocs.Viewer groups individual characters into words to improve rendering performance. If your document contains hieroglyphic or special symbols, you may need to disable character grouping to generate a more precise layout. To do this, use the [PdfOptions.disable_chars_grouping]((https://reference.groupdocs.com/viewer/python-net/groupdocs.viewer.options/pdfoptions/#properties) method, as shown below:

with gv.Viewer("resume.pdf") as viewer:
    # Create a PNG image for each PDF page.
    # {0} is replaced with the current page number in the image name.
    viewOptions = gvo.PngViewOptions("output_{0}.png")
    # Disable character grouping.
    viewOption.pdf_options.disable_chars_grouping = True
    viewer.view(viewOptions)

Use the ViewOptions.render_comments method for a target view to display textual annotations (such as text comments, sticky notes, text boxes and callouts) in the output HTML, PNG, or JPEG files.

The code example below renders a PDF file with text comments as an image.

with gv.Viewer("resume.pdf") as viewer:
    # Create a PNG image for each PDF page.
    # {0} is replaced with the current page number in the image name.
    viewOptions = gvo.PngViewOptions("output_{0}.png")
    # Enable rendering comments.
    viewOptions.render_comments = True
    viewer.view(viewOptions)

The following image illustrates the result:

Follow the steps below to obtain information about a PDF file (the number of pages, page size, and printing permissions):

1. Create a ViewInfoOptions instance for a specific view.
2. Call the Viewer.get_view_info method, pass the ViewInfoOptions instance to this method as a parameter, and cast the returned object to the PdfViewInfo type.
3. Use the PdfViewInfo class properties to retrieve document-specific information.

import GroupDocs.Viewer as gv
import GroupDocs.Viewer.options as gvo
import GroupDocs.Viewer.results as gvr

with gv.Viewer("resume.pdf") as viewer:
    viewInfoOptions = gvo.ViewInfoOptions.for_html_view()
    view_info = viewer.get_view_info(viewInfoOptions)
    pdf_info = cast(gvr.PdfViewInfo, view_info)
    # Display information about the PDF document.
    print("File type:", pdf_info.file_type)
    print("The number of pages:", len(pdf_info.pages))
    print("Is printing allowed:", pdf_info.printing_allowed)

The following image shows a sample console output:

Use the ViewInfoOptions.extract_text method to enable PDF text extraction. Use the PdfViewInfo.pages methods to obtain the list of all document pages, and use the Page.lines method to retrieve text for each line.

import sys

with gv.Viewer("resume.pdf") as viewer:
    view_info_options = gvo.ViewInfoOptions.for_html_view()
    view_info_options.extract_text = True

    view_info = viewer.getViewInfo(view_info_options)

    # Retrieve text from the PDF file.
    sys.stdout.reconfigure(encoding='utf-8')

    for page in view_info.pages:
        print(f"Page: {page.number}")
        print("Text lines/words/characters:")

        for line in page.lines:
            text = str(line)
            encoded_line = text.encode('utf-8')
            sys.stdout.buffer.write(encoded_line)

            for word in line.words:
                print("\t" + word.value)
                for character in word.characters:
                    print("\t\t" + character.value)