Optimizer

1//---------------------------------------------------------------------------------------
2// Copyright (c) 2001-2021 by PDFTron Systems Inc. All Rights Reserved.
3// Consult legal.txt regarding legal and license information.
4//---------------------------------------------------------------------------------------
5
6using System;
7using System.IO;
8
9using pdftron;
10using pdftron.Common;
11using pdftron.Filters;
12using pdftron.SDF;
13using pdftron.PDF;
14
15using NUnit.Framework;
16
17namespace MiscellaneousSamples
18{
19	[TestFixture]
20	public class OptimizerTest
21	{
22		
23		/// <summary>
24        /// The following sample illustrates how to reduce PDF file size using 'pdftron.PDF.Optimizer'.
25        /// The sample also shows how to simplify and optimize PDF documents for viewing on mobile devices 
26        /// and on the Web using 'pdftron.PDF.Flattener'.
27        ///
28        /// @note Both 'Optimizer' and 'Flattener' are separately licensable add-on options to the core PDFNet license.
29        ///
30        /// ----
31        ///
32        /// 'pdftron.PDF.Optimizer' can be used to optimize PDF documents by reducing the file size, removing 
33        /// redundant information, and compressing data streams using the latest in image compression technology. 
34        ///
35        /// PDF Optimizer can compress and shrink PDF file size with the following operations:
36		/// - Remove duplicated fonts, images, ICC profiles, and any other data stream. 
37		/// - Optionally convert high-quality or print-ready PDF files to small, efficient and web-ready PDF. 
38		/// - Optionally down-sample large images to a given resolution. 
39		/// - Optionally compress or recompress PDF images using JBIG2 and JPEG2000 compression formats. 
40		/// - Compress uncompressed streams and remove unused PDF objects.
41        /// 
42        /// ----
43        ///
44        /// 'pdftron.PDF.Flattener' can be used to speed-up PDF rendering on mobile devices and on the Web by 
45        /// simplifying page content (e.g. flattening complex graphics into images) while maintaining vector text 
46        /// whenever possible.
47        ///
48        /// Flattener can also be used to simplify process of writing custom converters from PDF to other formats. 
49        /// In this case, Flattener can be used as first step in the conversion pipeline to reduce any PDF to a 
50        /// very simple representation (e.g. vector text on top of a background image).
51		/// </summary>
52		[Test]
53		public static void Sample()
54		{
55
56			const string input_path =  "TestFiles/";
57			string input_filename = "newsletter";
58
59
60			//--------------------------------------------------------------------------------
61			// Example 1) Simple optimization of a pdf with default settings. 
62			//
63			try
64			{
65				using (PDFDoc doc = new PDFDoc(Utils.GetAssetTempFile(input_path + input_filename + ".pdf")))
66				{
67					doc.InitSecurityHandler();
68					Optimizer.Optimize(doc);
69					doc.Save(Utils.CreateExternalFile(input_filename + "_opt1.pdf"), SDFDoc.SaveOptions.e_linearized);
70				}
71			}
72			catch (PDFNetException e)
73			{
74				Console.WriteLine(e.Message);
75				Assert.True(false);
76			}
77				
78			//--------------------------------------------------------------------------------
79			// Example 2) Reduce image quality and use jpeg compression for
80			// non monochrome images.
81			try
82			{
83				using (PDFDoc doc = new PDFDoc(Utils.GetAssetTempFile(input_path + input_filename + ".pdf")))
84				{
85					doc.InitSecurityHandler();
86
87					Optimizer.ImageSettings image_settings = new Optimizer.ImageSettings();
88
89					// low quality jpeg compression
90					image_settings.SetCompressionMode(Optimizer.ImageSettings.CompressionMode.e_jpeg);
91					image_settings.SetQuality(1);
92
93					// Set the output dpi to be standard screen resolution
94					image_settings.SetImageDPI(144,96);
95
96					// this option will recompress images not compressed with
97					// jpeg compression and use the result if the new image
98					// is smaller.
99					image_settings.ForceRecompression(true);
100
101					// this option is not commonly used since it can 
102					// potentially lead to larger files.  It should be enabled
103					// only if the output compression specified should be applied
104					// to every image of a given type regardless of the output image size
105					//image_settings.ForceChanges(true);
106
107					// use the same settings for both color and grayscale images
108					Optimizer.OptimizerSettings opt_settings = new Optimizer.OptimizerSettings();
109					opt_settings.SetColorImageSettings(image_settings);
110					opt_settings.SetGrayscaleImageSettings(image_settings);
111
112					
113					Optimizer.Optimize(doc, opt_settings);
114
115					doc.Save(Utils.CreateExternalFile(input_filename + "_opt2.pdf"), SDFDoc.SaveOptions.e_linearized);
116				}
117			}
118			catch (PDFNetException e)
119			{
120				Console.WriteLine(e.Message);
121				Assert.True(false);
122			}
123
124
125			//--------------------------------------------------------------------------------
126			// Example 3) Use monochrome image settings and default settings
127			// for color and grayscale images. 
128			try
129			{
130				using (PDFDoc doc = new PDFDoc(Utils.GetAssetTempFile(input_path + input_filename + ".pdf")))
131				{
132					doc.InitSecurityHandler();
133
134					Optimizer.MonoImageSettings mono_image_settings = new Optimizer.MonoImageSettings();
135
136					mono_image_settings.SetCompressionMode(Optimizer.MonoImageSettings.CompressionMode.e_jbig2);
137					mono_image_settings.ForceRecompression(true);
138
139					Optimizer.OptimizerSettings opt_settings = new Optimizer.OptimizerSettings();
140					opt_settings.SetMonoImageSettings(mono_image_settings);
141
142					Optimizer.Optimize(doc, opt_settings);
143
144					doc.Save(Utils.CreateExternalFile(input_filename + "_opt3.pdf"), SDFDoc.SaveOptions.e_linearized);
145				}
146			}
147			catch (PDFNetException e)
148			{
149				Console.WriteLine(e.Message);
150				Assert.True(false);
151			}
152
153            //-------------------------------------------------------------------------------
154            // Example 4) Use Flattener to simplify content in this document
155            // using default settings
156
157	        try
158	        {
159		        using (PDFDoc doc = new PDFDoc(Utils.GetAssetTempFile(input_path + "TigerText.pdf")))
160                {
161		            doc.InitSecurityHandler();
162
163		            Flattener fl = new Flattener();
164
165		            // The following lines can increase the resolution of background
166		            // images.
167		            //fl.SetDPI(300);
168		            //fl.SetMaximumImagePixels(5000000);
169
170		            // This line can be used to output Flate compressed background
171		            // images rather than DCTDecode compressed images which is the default
172		            //fl.SetPreferJPG(false);
173
174		            // In order to adjust thresholds for when text is Flattened
175		            // the following function can be used.
176		            //fl.SetThreshold(Flattener.Threshold.e_keep_most);
177
178		            // We use e_fast option here since it is usually preferable
179		            // to avoid Flattening simple pages in terms of size and 
180		            // rendering speed. If the desire is to simplify the 
181		            // document for processing such that it contains only text and
182		            // a background image e_simple should be used instead.
183		            fl.Process(doc,Flattener.FlattenMode.e_fast);
184
185		            doc.Save(Utils.CreateExternalFile("TigerText_flatten.pdf"), SDFDoc.SaveOptions.e_linearized);
186                }
187	        }
188	        catch (PDFNetException e)
189	        {
190				Console.WriteLine(e.Message);	
191				Assert.True(false);
192	        }
193
194            //-------------------------------------------------------------------------------
195            // Example 5) Optimize a PDF for viewing using SaveViewerOptimized.
196
197            try
198            {
199                using (PDFDoc doc = new PDFDoc(Utils.GetAssetTempFile(input_path + input_filename + ".pdf")))
200                {
201                    doc.InitSecurityHandler();
202
203                    ViewerOptimizedOptions opts = new ViewerOptimizedOptions();
204
205                    // set the maximum dimension (width or height) that thumbnails will have.
206                    opts.SetThumbnailSize(1500);
207
208                    // set thumbnail rendering threshold. A number from 0 (include all thumbnails) to 100 (include only the first thumbnail) 
209                    // representing the complexity at which SaveViewerOptimized would include the thumbnail. 
210                    // By default it only produces thumbnails on the first and complex pages. 
211                    // The following line will produce thumbnails on every page.
212                    // opts.SetThumbnailRenderingThreshold(0); 
213
214                    doc.SaveViewerOptimized(Utils.CreateExternalFile(input_filename + "_SaveViewerOptimized.pdf"), opts);
215                }
216            }
217            catch (PDFNetException e)
218            {
219                Console.WriteLine(e.Message);
220                Assert.True(false);
221            }
222        }
223	}
224}