> For the complete documentation index, see [llms.txt](https://docs.apryse.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.apryse.com/xamarin/get-started/samples/optimizertest.md). # Optimizer This guide will walk you thorugh how to compress PDF file using C#. WebViewer makes it easy to reduce images, Unembed fonts, Remove unused objects with C# Sample C# code for using Apryse SDK to reduce PDF file size by removing redundant information and compressing data streams using the latest in image compression technology. Learn more about our [Xamarin SDK](/core/get-started/frameworks/dotnet.md). {% tabs %} {% tab title="C#" %} {% code lineNumbers="true" %} ```csharp //--------------------------------------------------------------------------------------- // Copyright (c) 2001-2021 by PDFTron Systems Inc. All Rights Reserved. // Consult legal.txt regarding legal and license information. //--------------------------------------------------------------------------------------- using System; using System.IO; using pdftron; using pdftron.Common; using pdftron.Filters; using pdftron.SDF; using pdftron.PDF; using NUnit.Framework; namespace MiscellaneousSamples { [TestFixture] public class OptimizerTest { /// /// The following sample illustrates how to reduce PDF file size using 'pdftron.PDF.Optimizer'. /// The sample also shows how to simplify and optimize PDF documents for viewing on mobile devices /// and on the Web using 'pdftron.PDF.Flattener'. /// /// @note Both 'Optimizer' and 'Flattener' are separately licensable add-on options to the core PDFNet license. /// /// ---- /// /// 'pdftron.PDF.Optimizer' can be used to optimize PDF documents by reducing the file size, removing /// redundant information, and compressing data streams using the latest in image compression technology. /// /// PDF Optimizer can compress and shrink PDF file size with the following operations: /// - Remove duplicated fonts, images, ICC profiles, and any other data stream. /// - Optionally convert high-quality or print-ready PDF files to small, efficient and web-ready PDF. /// - Optionally down-sample large images to a given resolution. /// - Optionally compress or recompress PDF images using JBIG2 and JPEG2000 compression formats. /// - Compress uncompressed streams and remove unused PDF objects. /// /// ---- /// /// 'pdftron.PDF.Flattener' can be used to speed-up PDF rendering on mobile devices and on the Web by /// simplifying page content (e.g. flattening complex graphics into images) while maintaining vector text /// whenever possible. /// /// Flattener can also be used to simplify process of writing custom converters from PDF to other formats. /// In this case, Flattener can be used as first step in the conversion pipeline to reduce any PDF to a /// very simple representation (e.g. vector text on top of a background image). /// [Test] public static void Sample() { const string input_path = "TestFiles/"; string input_filename = "newsletter"; //-------------------------------------------------------------------------------- // Example 1) Simple optimization of a pdf with default settings. // try { using (PDFDoc doc = new PDFDoc(Utils.GetAssetTempFile(input_path + input_filename + ".pdf"))) { doc.InitSecurityHandler(); Optimizer.Optimize(doc); doc.Save(Utils.CreateExternalFile(input_filename + "_opt1.pdf"), SDFDoc.SaveOptions.e_linearized); } } catch (PDFNetException e) { Console.WriteLine(e.Message); Assert.True(false); } //-------------------------------------------------------------------------------- // Example 2) Reduce image quality and use jpeg compression for // non monochrome images. try { using (PDFDoc doc = new PDFDoc(Utils.GetAssetTempFile(input_path + input_filename + ".pdf"))) { doc.InitSecurityHandler(); Optimizer.ImageSettings image_settings = new Optimizer.ImageSettings(); // low quality jpeg compression image_settings.SetCompressionMode(Optimizer.ImageSettings.CompressionMode.e_jpeg); image_settings.SetQuality(1); // Set the output dpi to be standard screen resolution image_settings.SetImageDPI(144,96); // this option will recompress images not compressed with // jpeg compression and use the result if the new image // is smaller. image_settings.ForceRecompression(true); // this option is not commonly used since it can // potentially lead to larger files. It should be enabled // only if the output compression specified should be applied // to every image of a given type regardless of the output image size //image_settings.ForceChanges(true); // use the same settings for both color and grayscale images Optimizer.OptimizerSettings opt_settings = new Optimizer.OptimizerSettings(); opt_settings.SetColorImageSettings(image_settings); opt_settings.SetGrayscaleImageSettings(image_settings); Optimizer.Optimize(doc, opt_settings); doc.Save(Utils.CreateExternalFile(input_filename + "_opt2.pdf"), SDFDoc.SaveOptions.e_linearized); } } catch (PDFNetException e) { Console.WriteLine(e.Message); Assert.True(false); } //-------------------------------------------------------------------------------- // Example 3) Use monochrome image settings and default settings // for color and grayscale images. try { using (PDFDoc doc = new PDFDoc(Utils.GetAssetTempFile(input_path + input_filename + ".pdf"))) { doc.InitSecurityHandler(); Optimizer.MonoImageSettings mono_image_settings = new Optimizer.MonoImageSettings(); mono_image_settings.SetCompressionMode(Optimizer.MonoImageSettings.CompressionMode.e_jbig2); mono_image_settings.ForceRecompression(true); Optimizer.OptimizerSettings opt_settings = new Optimizer.OptimizerSettings(); opt_settings.SetMonoImageSettings(mono_image_settings); Optimizer.Optimize(doc, opt_settings); doc.Save(Utils.CreateExternalFile(input_filename + "_opt3.pdf"), SDFDoc.SaveOptions.e_linearized); } } catch (PDFNetException e) { Console.WriteLine(e.Message); Assert.True(false); } //------------------------------------------------------------------------------- // Example 4) Use Flattener to simplify content in this document // using default settings try { using (PDFDoc doc = new PDFDoc(Utils.GetAssetTempFile(input_path + "TigerText.pdf"))) { doc.InitSecurityHandler(); Flattener fl = new Flattener(); // The following lines can increase the resolution of background // images. //fl.SetDPI(300); //fl.SetMaximumImagePixels(5000000); // This line can be used to output Flate compressed background // images rather than DCTDecode compressed images which is the default //fl.SetPreferJPG(false); // In order to adjust thresholds for when text is Flattened // the following function can be used. //fl.SetThreshold(Flattener.Threshold.e_keep_most); // We use e_fast option here since it is usually preferable // to avoid Flattening simple pages in terms of size and // rendering speed. If the desire is to simplify the // document for processing such that it contains only text and // a background image e_simple should be used instead. fl.Process(doc,Flattener.FlattenMode.e_fast); doc.Save(Utils.CreateExternalFile("TigerText_flatten.pdf"), SDFDoc.SaveOptions.e_linearized); } } catch (PDFNetException e) { Console.WriteLine(e.Message); Assert.True(false); } //------------------------------------------------------------------------------- // Example 5) Optimize a PDF for viewing using SaveViewerOptimized. try { using (PDFDoc doc = new PDFDoc(Utils.GetAssetTempFile(input_path + input_filename + ".pdf"))) { doc.InitSecurityHandler(); ViewerOptimizedOptions opts = new ViewerOptimizedOptions(); // set the maximum dimension (width or height) that thumbnails will have. opts.SetThumbnailSize(1500); // set thumbnail rendering threshold. A number from 0 (include all thumbnails) to 100 (include only the first thumbnail) // representing the complexity at which SaveViewerOptimized would include the thumbnail. // By default it only produces thumbnails on the first and complex pages. // The following line will produce thumbnails on every page. // opts.SetThumbnailRenderingThreshold(0); doc.SaveViewerOptimized(Utils.CreateExternalFile(input_filename + "_SaveViewerOptimized.pdf"), opts); } } catch (PDFNetException e) { Console.WriteLine(e.Message); Assert.True(false); } } } } ``` {% endcode %} {% endtab %} {% endtabs %} --- # Agent Instructions This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. 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