Section:

ImageExtract

Sample C# code for using Apryse SDK to extract images from PDF files, along with their positioning information and DPI. Instead of converting PDF images to a Bitmap, you can also extract uncompressed/compressed image data directly using element.GetImageData() (described in the PDF Data Extraction code sample). Learn more about our Server SDK and PDF Data Extraction SDK Capabilities.

1//
2// Copyright (c) 2001-2024 by Apryse Software Inc. All Rights Reserved.
3//
4
5using System;
6using System.Drawing;
7using System.Drawing.Imaging;
8
9using pdftron;
10using pdftron.Common;
11using pdftron.PDF;
12using pdftron.SDF;
13using pdftron.Filters;
14
15namespace ImageExtractTestCS
16{
17	class Class1
18	{
19		/// <summary>
20		///-----------------------------------------------------------------------------------
21		/// This sample illustrates one approach to PDF image extraction 
22		/// using PDFNet.
23		/// 
24		/// Note: Besides direct image export, you can also convert PDF images 
25		/// to GDI+ Bitmap, or extract uncompressed/compressed image data directly 
26		/// using element.GetImageData() (e.g. as illustrated in ElementReaderAdv 
27		/// sample project).
28		///-----------------------------------------------------------------------------------
29		/// </summary>
30
31		private static pdftron.PDFNetLoader pdfNetLoader = pdftron.PDFNetLoader.Instance();
32		static Class1() {}
33
34		static int image_counter = 0;
35
36		// Relative path to the folder containing test files.
37		static string input_path =  "../../../../TestFiles/";
38		static string output_path = "../../../../TestFiles/Output/";
39
40		static void ImageExtract(PDFDoc doc, ElementReader reader) 
41		{
42			Element element; 
43			while ((element = reader.Next()) != null)
44			{
45				switch (element.GetType()) 
46				{
47					case Element.Type.e_image:
48					case Element.Type.e_inline_image:
49					{
50						Console.WriteLine("--> Image: {0}", ++image_counter);
51						Console.WriteLine("    Width: {0}", element.GetImageWidth());
52						Console.WriteLine("    Height: {0}", element.GetImageHeight());
53						Console.WriteLine("    BPC: {0}", element.GetBitsPerComponent());
54
55						Matrix2D ctm = element.GetCTM();
56						double x2=1, y2=1, y1=ctm.m_v;
57						ctm.Mult(ref x2, ref y2);
58						// Write the coords to 3 decimal places.
59						Console.WriteLine("    Coords: x1={0:N2}, y1={1:N2}, x2={2:N2}, y2={3:N2}", ctm.m_h, ctm.m_v, x2, y2);
60						pdftron.PDF.Image image = null;
61						if (element.GetType() == Element.Type.e_image) 
62						{
63							image = new pdftron.PDF.Image(element.GetXObject());
64
65							string fname = output_path + "image_extract1_" + image_counter.ToString();
66							image.Export(fname);  // or ExporAsPng() or ExporAsTiff() ...
67						}
68						break;
69					}
70					case Element.Type.e_form: // Process form XObjects
71					{
72						reader.FormBegin(); 
73						ImageExtract(doc, reader);
74						reader.End(); 
75						break; 
76					}
77				}
78			}
79		}
80
81		static void Main(string[] args)
82		{
83			PDFNet.Initialize(PDFTronLicense.Key);
84			
85			// Example 1: 
86			// Extract images by traversing the display list for 
87			// every page. With this approach it is possible to obtain 
88			// image positioning information and DPI.
89			try	
90			{
91				using (PDFDoc doc = new PDFDoc(input_path + "newsletter.pdf"))
92				using (ElementReader reader = new ElementReader())
93				{
94					doc.InitSecurityHandler();
95					PageIterator itr;
96					for (itr=doc.GetPageIterator(); itr.HasNext(); itr.Next())	
97					{				
98						reader.Begin(itr.Current());
99						ImageExtract(doc, reader);
100						reader.End();
101					}
102
103					Console.WriteLine("Done.");
104				}
105			}
106			catch (PDFNetException e)
107			{
108				Console.WriteLine(e.Message);
109			}
110
111			Console.WriteLine("----------------------------------------------------------------");
112
113			// Example 2: 
114			// Extract images by scanning the low-level document.
115			try	
116			{
117				using (PDFDoc doc = new PDFDoc(input_path + "newsletter.pdf"))
118				{
119					doc.InitSecurityHandler();
120					image_counter = 0;
121
122					SDFDoc cos_doc = doc.GetSDFDoc();
123					int num_objs = cos_doc.XRefSize();
124					for (int i=1; i<num_objs; ++i)
125					{
126						Obj obj = cos_doc.GetObj(i);
127						if (obj!=null && !obj.IsFree()&& obj.IsStream()) 
128						{
129							// Process only images
130							DictIterator itr = obj.Find("Subtype");
131							if (!itr.HasNext() || itr.Value().GetName() != "Image") 
132								continue; 
133
134							itr = obj.Find("Type");
135							if (!itr.HasNext() || itr.Value().GetName() != "XObject") 
136								continue;
137
138							pdftron.PDF.Image image = new pdftron.PDF.Image(obj);
139
140							Console.WriteLine("--> Image: {0}", ++image_counter);
141							Console.WriteLine("    Width: {0}", image.GetImageWidth());
142							Console.WriteLine("    Height: {0}", image.GetImageHeight());
143							Console.WriteLine("    BPC: {0}", image.GetBitsPerComponent());
144
145							string fname = output_path + "image_extract2_" + image_counter.ToString();
146							image.Export(fname);  // or ExporAsPng() or ExporAsTiff() ...
147
148							// Convert PDF bitmap to GDI+ Bitmap...
149							//Bitmap bmp = image.GetBitmap();
150							//bmp.Save(fname, ImageFormat.Png);
151							//bmp.Dispose();
152
153							// Instead of converting PDF images to a Bitmap, you can also extract 
154							// uncompressed/compressed image data directly using element.GetImageData() 
155							// as illustrated in ElementReaderAdv sample project.
156						}
157					}
158					Console.WriteLine("Done.");
159				}
160			}
161			catch (PDFNetException e)
162			{
163				Console.WriteLine(e.Message);
164			}
165			PDFNet.Terminate();
166
167		}
168	}
169}

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