How to change the file size of PDF with images
Environment
| Version | Product | Author |
|---|---|---|
| 2024.1.305 | RadPdfProcessing | Yoan Karamanov |
Description
This article shows how to change the file size of a PDF with images by changing the image compression and image quality.
Solution
The size of the exported PDF file depends on the value of the ImageQuality and ImageCompression properties of the PDF Export Setting. You can try different combinations with these values in order to achieve different results.
This example showcases all four ImageCompression options and how each option behaves with a different ImageQuiality. In general, lowering the image quality will lower the file size.
The result file sizes seen in the comments are based on a sample document and should be just used as reference.
using Telerik.Windows.Documents.Fixed.FormatProviders.Pdf;
using Telerik.Windows.Documents.Fixed.FormatProviders.Pdf.Export;
using Telerik.Windows.Documents.Fixed.Model;
//Required in .NET Standard
//Telerik.Windows.Documents.Extensibility.JpegImageConverterBase defaultJpegImageConverter = new Telerik.Documents.ImageUtils.JpegImageConverter();
//Telerik.Windows.Documents.Extensibility.FixedExtensibilityManager.JpegImageConverter = defaultJpegImageConverter;
RadFixedDocument document;
PdfFormatProvider pdfFormatProvider = new PdfFormatProvider();
using (Stream input = File.OpenRead("input.pdf"))
{
document = pdfFormatProvider.Import(input);
}
var settings = new PdfExportSettings();
#region ImageCompression - None
// 182,000 KB file size ||
settings.ImageCompression = new ImageFilterTypes[] { ImageFilterTypes.None };
// ImageQuality has no effect if this is set
#endregion
#region ImageCompression - FlateDecode
// 114,000 KB file size || default ImageQuality is High
settings.ImageCompression = new ImageFilterTypes[] { ImageFilterTypes.FlateDecode };
// 114,000 KB file size - no difference with the default setting
settings.ImageQuality = ImageQuality.High;
// 71,000 KB file size
settings.ImageQuality = ImageQuality.Medium;
// 27,000 KB
settings.ImageQuality = ImageQuality.Low;
#endregion
#region ImageCompression - Default
//around 35,500 KB || default ImageQuality is High
settings.ImageCompression = new ImageFilterTypes[] { ImageFilterTypes.Default };
//around 35,500 KB - no difference with the default setting
settings.ImageQuality = ImageQuality.High;
//around 1,000 KB file size
settings.ImageQuality = ImageQuality.Low;
//around 3,600 KB file size
settings.ImageQuality = ImageQuality.Medium;
#endregion
#region ImageCompression - DCTDecode
// 34,500 KB file size || default ImageQuality is High
settings.ImageCompression = new ImageFilterTypes[] { ImageFilterTypes.DCTDecode };
// 34,500 KB file size - no difference with the default setting
settings.ImageQuality = ImageQuality.High;
// 1,000 KB
settings.ImageQuality = ImageQuality.Low;
// 3,600 KB
settings.ImageQuality = ImageQuality.Medium;
#endregion
pdfFormatProvider.ExportSettings = settings;
using (Stream output = File.OpenWrite("output.pdf"))
{
pdfFormatProvider.Export(document, output);
}