How to Rasterize a PDF to Images in C#

Where Are the Output Images Saved?

By default, output images are saved to the application's current working directory, typically the bin/Debug or bin/Release folder of your project. You can specify an absolute or relative path to save images to a custom location. For example, @"C:\Output\page_*.png" saves images to the C:\Output directory.

If form field values should be visible in output images, flatten the PDF before converting it to an image or pass true to the Flatten parameter of the method. Forms will not be detectable after using the Flatten method. Learn more about flattening PDFs to understand the process better.

Learn how to fill and edit PDF forms programmatically in the article: "How to Fill and Edit PDF Forms."

How Can I Generate High-Quality Bitmap Images?

To retain the original resolution of images when converting to a Bitmap, use ToBitmapHighQuality instead of ToBitmap. The ToBitmap method returns an image decoded from JPEG, while the ToBitmapHighQuality method returns an image decoded from the BMP format.

The BMP format stores raw pixel data, resulting in sharper images but larger file sizes. JPEG uses lossy compression, significantly reducing file size at the cost of slight blurriness. For most use cases like printing and viewing PDFs, JPEG image quality is sufficient. For PDFs requiring high visual fidelity, explore our guide on pixel-perfect HTML formatting.

:path=/static-assets/pdf/content-code-examples/how-to/rasterize-pdf-to-images-to-bitmap-high-quality.cs

using IronPdf;

PdfDocument pdf = PdfDocument.FromFile("url.pdf");

var image = pdf.ToBitmapHighQuality();
image[0].SaveAs("output.png");

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Which Image Formats Can I Export To?

Another parameter allows you to specify file types for output images. Supported formats include BMP, JPEG, PNG, GIF, TIFF, and SVG. Each type has a corresponding method that can be directly invoked from the PdfDocument object:

• ToBitmap: Rasterizes the PDF into individual AnyBitmap objects, one Bitmap per page.
• ToJpegImages: Renders PDF pages as JPEG files and saves to disk.
• ToPngImages: Renders PDF pages as PNG files and saves to disk.
• ToTiffImages: Renders PDF pages as single-page TIFF files and saves to disk.
• ToMultiPageTiffImage: Renders PDF pages as a single multi-page TIFF file.
• SaveAsSvg: Converts the PDF to SVG format and saves to the specified path.
• ToSvgString: Converts a specific PDF page to SVG format and returns as a string.

For working with vector graphics, explore our guide on using SVG graphics in PDF generation, which complements SVG export functionality.

:path=/static-assets/pdf/content-code-examples/how-to/rasterize-pdf-to-images-image-type.cs

How Do I Improve Image Clarity with DPI Settings?

The default DPI of 96 may produce blurry output images. To improve clarity, specify a higher DPI value when rasterizing. DPI (dots per inch) directly affects resolution and file size. Higher DPI values produce clearer images but result in larger file sizes.

Common DPI settings:

• 96 DPI: Standard screen resolution for web display
• 150 DPI: Good for general document viewing
• 300 DPI: High quality for printing
• 600 DPI: Professional printing quality

:path=/static-assets/pdf/content-code-examples/how-to/rasterize-pdf-to-images-dpi.cs

using IronPdf;

// Instantiate Renderer
ChromePdfRenderer renderer = new ChromePdfRenderer();

// Render PDF from web URL
PdfDocument pdf = renderer.RenderUrlAsPdf("https://en.wikipedia.org/wiki/Main_Page");

// Export images from PDF with DPI 150
pdf.RasterizeToImageFiles("wikipage_*.png", DPI: 150);

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How Do I Convert Specific Pages to Images?

You can specify which pages of the PDF document to rasterize into images. The example below generates images of PDF pages 1-3. This feature is useful for creating thumbnails of specific pages or when working with large PDF documents where only certain pages need to be images.

:path=/static-assets/pdf/content-code-examples/how-to/rasterize-pdf-to-images-page-indexes.cs

using IronPdf;
using System.Linq;

// Instantiate Renderer
ChromePdfRenderer renderer = new ChromePdfRenderer();

// Render PDF from web URL
PdfDocument pdf = renderer.RenderUrlAsPdf("https://en.wikipedia.org/wiki/Main_Page");

// Export images from PDF page 1_3
pdf.RasterizeToImageFiles("wikipage_*.png", Enumerable.Range(1, 3));

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For advanced page manipulation, explore our guides on adding, copying, and deleting pages or splitting PDFs.

How Do I Control Output Image Dimensions?

When converting PDF documents to images, you can customize the height and width of output images. The specified values represent maximum dimensions while preserving the aspect ratio of the original document. For a portrait PDF document, the specified height value will be exact, while the width adjusts to maintain the correct aspect ratio.

This feature is essential when images must fit specific dimensions for web display, thumbnails, or other applications requiring consistent sizing. Aspect ratio preservation ensures content doesn't appear stretched or distorted.

:path=/static-assets/pdf/content-code-examples/how-to/rasterize-pdf-to-images-image-dimensions.cs

using IronPdf;

// Instantiate Renderer
ChromePdfRenderer renderer = new ChromePdfRenderer();

// Render PDF from web URL
PdfDocument pdf = renderer.RenderUrlAsPdf("https://en.wikipedia.org/wiki/Main_Page");

// Export images from PDF
pdf.RasterizeToImageFiles("wikipage_*.png", 500, 500);

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What Happens to Aspect Ratios When Setting Dimensions?

Output image dimensions are specified using width by height format (width x height). IronPDF intelligently handles aspect ratio preservation to ensure images maintain original proportions.

Portrait

Landscape