Section:

Handwriting ICR to search PDFs and Extract Text - Java Sample Code

Requirements
View Demo
Server SDK
Package: OCR
Module: OCR

Sample code shows how to use the Apryse Server OCR module on scanned documents in multiple languages; provided in Python, C++, C# (.Net), Java, Node.js (JavaScript), PHP, Ruby and VB. The OCR module can make searchable PDFs and extract scanned text for further indexing.

Looking for OCR + WebViewer? Check out our OCR - Showcase Sample Code

Learn more about our Server SDK and OCR capabilities.

Implementation steps

To run this sample, you will need:

  1. Get started with Server SDK in your language/framework.
  2. Download ICR Module.
  3. Add the sample code provided below.

To use this feature in production, your license key will need the ICR Package. Trial keys already include this package.

1//---------------------------------------------------------------------------------------
2// Copyright (c) 2001-2026 by Apryse Software Inc. All Rights Reserved.
3// Consult legal.txt regarding legal and license information.
4//---------------------------------------------------------------------------------------
5
6import java.io.FileWriter;
7import java.io.BufferedWriter;
8import java.io.IOException;
9
10import com.pdftron.common.PDFNetException;
11import com.pdftron.pdf.*;
12import com.pdftron.sdf.SDFDoc;
13
14//---------------------------------------------------------------------------------------
15// The Handwriting ICR Module is an optional PDFNet add-on that can be used to extract
16// handwriting from image-based pages and apply them as hidden text.
17//
18// The Apryse SDK Handwriting ICR Module can be downloaded from https://dev.apryse.com/
19//---------------------------------------------------------------------------------------
20public class HandwritingICRTest {
21
22	static void writeTextToFile(String filename, String text) throws IOException
23	{
24		BufferedWriter writer = new BufferedWriter(new FileWriter(filename));
25		writer.write(text);
26		writer.close();
27	}
28
29	public static void main(String[] args) {
30		try {
31			// The first step in every application using PDFNet is to initialize the 
32			// library and set the path to common PDF resources. The library is usually 
33			// initialized only once, but calling Initialize() multiple times is also fine.
34			PDFNet.initialize(PDFTronLicense.Key());
35
36			// The location of the Handwriting ICR Module
37			PDFNet.addResourceSearchPath("../../../Lib/");
38
39			// Test if the add-on is installed
40			if (!HandwritingICRModule.isModuleAvailable())
41			{
42				System.out.println("");
43				System.out.println("Unable to run HandwritingICRTest: Apryse SDK Handwriting ICR Module");
44				System.out.println("not available.");
45				System.out.println("---------------------------------------------------------------");
46				System.out.println("The Handwriting ICR Module is an optional add-on, available for download");
47				System.out.println("at https://dev.apryse.com/. If you have already downloaded this");
48				System.out.println("module, ensure that the SDK is able to find the required files");
49				System.out.println("using the PDFNet.addResourceSearchPath() function.");
50				System.out.println("");
51				return;
52			}
53
54			// Relative path to the folder containing test files.
55			String input_path = "../../TestFiles/HandwritingICR/";
56			String output_path = "../../TestFiles/Output/";
57
58			//--------------------------------------------------------------------------------
59			// Example 1) Process a PDF without specifying options
60			System.out.println("Example 1: processing icr.pdf");
61				
62			// Open the .pdf document
63			try (PDFDoc doc = new PDFDoc(input_path + "icr.pdf"))
64			{
65				// Run ICR on the .pdf with the default options
66				HandwritingICRModule.processPDF(doc);
67
68				// Save the result with hidden text applied
69				doc.save(output_path + "icr-simple.pdf", SDFDoc.SaveMode.LINEARIZED, null);
70				doc.close();
71			} catch (PDFNetException e) {
72				e.printStackTrace();
73			}
74
75			//--------------------------------------------------------------------------------
76			// Example 2) Process a subset of PDF pages
77			System.out.println("Example 2: processing pages from icr.pdf");
78				
79			// Open the .pdf document
80			try (PDFDoc doc = new PDFDoc(input_path + "icr.pdf"))
81			{
82				// Process handwriting with custom options
83				HandwritingICROptions options = new HandwritingICROptions();
84
85				// Optionally, process a subset of pages
86				options.setPages("2-3");
87
88				// Run ICR on the .pdf
89				HandwritingICRModule.processPDF(doc, options);
90
91				// Save the result with hidden text applied
92				doc.save(output_path + "icr-pages.pdf", SDFDoc.SaveMode.LINEARIZED, null);
93				doc.close();
94			} catch (PDFNetException e) {
95				e.printStackTrace();
96			}
97
98			//--------------------------------------------------------------------------------
99			// Example 3) Ignore zones specified for each page
100			System.out.println("Example 3: processing & ignoring zones");
101				
102			// Open the .pdf document
103			try (PDFDoc doc = new PDFDoc(input_path + "icr.pdf"))
104			{
105				// Process handwriting with custom options
106				HandwritingICROptions options = new HandwritingICROptions();
107
108				// Process page 2 by ignoring the signature area on the bottom
109				options.setPages("2");
110				RectCollection ignore_zones_page2 = new RectCollection();
111				// These coordinates are in PDF user space, with the origin at the bottom left corner of the page.
112				// Coordinates rotate with the page, if it has rotation applied.
113				ignore_zones_page2.addRect(78, 850.1 - 770, 340, 850.1 - 676);
114				options.addIgnoreZonesForPage(ignore_zones_page2, 2);
115
116				// Run ICR on the .pdf
117				HandwritingICRModule.processPDF(doc, options);
118
119				// Save the result with hidden text applied
120				doc.save(output_path + "icr-ignore.pdf", SDFDoc.SaveMode.LINEARIZED, null);
121				doc.close();
122			} catch (PDFNetException e) {
123				e.printStackTrace();
124			}
125
126			//--------------------------------------------------------------------------------
127			// Example 4) The postprocessing workflow has also an option of extracting ICR results
128			// in JSON format, similar to the one used by the OCR Module
129			System.out.println("Example 4: extract & apply");
130				
131			// Open the .pdf document
132			try (PDFDoc doc = new PDFDoc(input_path + "icr.pdf"))
133			{
134				// Extract ICR results in JSON format
135				String json = HandwritingICRModule.getICRJsonFromPDF(doc);
136				writeTextToFile(output_path + "icr-get.json", json);
137
138				// Insert your post-processing step (whatever it might be)
139				// ...
140
141				// Apply potentially modified ICR JSON to the PDF
142				HandwritingICRModule.applyICRJsonToPDF(doc, json);
143
144				// Save the result with hidden text applied
145				doc.save(output_path + "icr-get-apply.pdf", SDFDoc.SaveMode.LINEARIZED, null);
146				doc.close();
147			} catch (PDFNetException e) {
148				e.printStackTrace();
149			}
150			catch (IOException e) {
151				System.out.println(e);
152			}
153			System.out.println("Done.");
154			PDFNet.terminate();
155		} catch (PDFNetException e) {
156			e.printStackTrace();
157		}
158	}
159}

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