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# Tesseract Platform
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JavaCPP platform aggregator for Tesseract OCR native libraries, providing comprehensive optical character recognition capabilities in Java applications. This package bundles cross-platform native libraries for Tesseract 5.5.1, enabling text extraction from images across Linux, macOS, Windows, and Android platforms.
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## Package Information 
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- **Package Name**: tesseract-platform
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- **Package Type**: Maven
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- **Group ID**: org.bytedeco
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- **Language**: Java
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- **Installation**: `org.bytedeco:tesseract-platform:5.5.1-1.5.12`
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## Core Imports
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```java
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import org.bytedeco.javacpp.*;
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import org.bytedeco.tesseract.*;
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import org.bytedeco.leptonica.*;
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import static org.bytedeco.tesseract.global.tesseract.*;
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import static org.bytedeco.leptonica.global.leptonica.*;
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```
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## Basic Usage
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```java
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import org.bytedeco.javacpp.*;
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import org.bytedeco.leptonica.*;
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import org.bytedeco.tesseract.*;
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import static org.bytedeco.leptonica.global.leptonica.*;
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import static org.bytedeco.tesseract.global.tesseract.*;
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public class BasicOCR {
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    public static void main(String[] args) {
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        TessBaseAPI api = new TessBaseAPI();
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        // Initialize tesseract with English language
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        if (api.Init(null, "eng") != 0) {
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            System.err.println("Could not initialize tesseract.");
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            return;
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        }
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        // Load image using Leptonica
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        PIX image = pixRead("image.png");
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        api.SetImage(image);
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        // Extract text
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        BytePointer outText = api.GetUTF8Text();
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        System.out.println("OCR Result: " + outText.getString());
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        // Cleanup
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        api.End();
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        outText.deallocate();
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        image.close();
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    }
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}
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```
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## Architecture
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The Tesseract platform provides a comprehensive OCR solution built on the JavaCPP framework:
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- **TessBaseAPI**: Main OCR engine interface providing initialization, configuration, and text extraction
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- **Iterator Hierarchy**: Structured navigation through recognition results (PageIterator → LTRResultIterator → ResultIterator)
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- **Renderer Pipeline**: Multiple output format generators for text, HTML, PDF, XML, and training data
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- **Native Integration**: Seamless integration with Leptonica image processing library
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- **Cross-Platform**: Platform-specific native libraries automatically loaded at runtime
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## Capabilities
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### Core OCR Engine
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Primary OCR functionality including initialization, image processing, text recognition, and result extraction. The TessBaseAPI class serves as the main entry point for all OCR operations.
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```java { .api }
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public class TessBaseAPI {
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    // Initialization
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    public TessBaseAPI();
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    public static native @Cast("const char*") BytePointer Version();
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    public int Init(String datapath, String language, int oem);
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    public int Init(String datapath, String language);
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    public void End();
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    // Image Processing  
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    public void SetImage(PIX pix);
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    public void SetImage(byte[] imagedata, int width, int height, int bytes_per_pixel, int bytes_per_line);
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    public void SetRectangle(int left, int top, int width, int height);
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    public PIX GetThresholdedImage();
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    // Recognition
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    public int Recognize(ETEXT_DESC monitor);
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    public native @Cast("char*") BytePointer TesseractRect(@Cast("const unsigned char*") byte[] imagedata, int bytes_per_pixel, int bytes_per_line, 
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                              int left, int top, int width, int height);
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    // Text Output
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    public native @Cast("char*") BytePointer GetUTF8Text();
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    public native @Cast("char*") BytePointer GetHOCRText(int page_number);
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    public native @Cast("char*") BytePointer GetTSVText(int page_number);
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    public int MeanTextConf();
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    public int[] AllWordConfidences();
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}
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```
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[Core OCR Engine](./core-ocr-engine.md)
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### Result Navigation
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Hierarchical iterators for navigating recognition results from page level down to individual characters. Provides access to bounding boxes, confidence scores, text formatting, and layout information.
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```java { .api }
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public class PageIterator {
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    public void Begin();
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    public boolean Next(int level);
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    public boolean BoundingBox(int level, int[] left, int[] top, int[] right, int[] bottom);
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    public boolean Baseline(int level, int[] x1, int[] y1, int[] x2, int[] y2);
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    public PIX GetBinaryImage(int level);
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    public int BlockType();
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    public void Orientation(int[] orientation, int[] writing_direction, 
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                          int[] textline_order, float[] deskew_angle);
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}
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public class ResultIterator extends LTRResultIterator {
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    public String GetUTF8Text(int level);
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    public float Confidence(int level);
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    public boolean ParagraphIsLtr();
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    public String WordFontAttributes(boolean[] is_bold, boolean[] is_italic, 
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                                   boolean[] is_underlined, boolean[] is_monospace, 
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                                   boolean[] is_serif, boolean[] is_smallcaps, 
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                                   int[] pointsize, int[] font_id);
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}
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```
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[Result Navigation](./result-navigation.md)
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### Output Renderers
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Configurable pipeline for generating output in multiple formats including plain text, structured markup (hOCR, ALTO, PAGE), searchable PDF, and training data formats.
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```java { .api }
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public abstract class TessResultRenderer {
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    public void insert(TessResultRenderer next);
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    public boolean BeginDocument(String title);
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    public boolean AddImage(TessBaseAPI api);
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    public boolean EndDocument();
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    public String file_extension();
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}
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// Concrete renderer classes
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public class TessTextRenderer extends TessResultRenderer;
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public class TessHOcrRenderer extends TessResultRenderer;
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public class TessPDFRenderer extends TessResultRenderer;
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public class TessAltoRenderer extends TessResultRenderer;
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public class TessTsvRenderer extends TessResultRenderer;
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```
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[Output Renderers](./output-renderers.md)
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### Layout Analysis
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Advanced page structure analysis including text block detection, reading order determination, and geometric layout information. Supports complex document layouts with tables, columns, and mixed content.
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```java { .api }
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public class TessBaseAPI {
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    public PageIterator AnalyseLayout();
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    public BOXA GetRegions(PIXA[] pixa);
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    public BOXA GetTextlines(PIXA[] pixa, int[][] blockids);
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    public BOXA GetWords(PIXA[] pixa);
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    public BOXA GetComponentImages(int level, boolean text_only, PIXA[] pixa, int[][] blockids);
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}
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// Layout analysis constants
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public static final int PSM_AUTO = 3;           // Fully automatic page segmentation
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public static final int PSM_SINGLE_COLUMN = 4; // Single column of text
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public static final int PSM_SINGLE_BLOCK = 6;  // Single uniform block of text
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public static final int PSM_SINGLE_LINE = 7;   // Single text line
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```
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[Layout Analysis](./layout-analysis.md)
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### Configuration and Parameters
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Comprehensive configuration system with hundreds of parameters controlling OCR behavior, page segmentation, character recognition, and output formatting.
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```java { .api }
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public class TessBaseAPI {
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    // Parameter Management
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    public boolean SetVariable(String name, String value);
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    public boolean GetIntVariable(String name, int[] value);
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    public boolean GetBoolVariable(String name, boolean[] value);
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    public boolean GetDoubleVariable(String name, double[] value);
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    public String GetStringVariable(String name);
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    // Page Segmentation
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    public void SetPageSegMode(int mode);
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    public int GetPageSegMode();
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    // OCR Engine Mode
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    public static final int OEM_TESSERACT_ONLY = 0;
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    public static final int OEM_LSTM_ONLY = 1; 
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    public static final int OEM_DEFAULT = 3;
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}
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```
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[Configuration](./configuration.md)
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### Language Support
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Multi-language OCR with support for 100+ languages, custom language models, and language detection capabilities.
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```java { .api }
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public class TessBaseAPI {
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    public String GetInitLanguagesAsString();
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    public void GetLoadedLanguagesAsVector(StringVector langs);
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    public void GetAvailableLanguagesAsVector(StringVector langs);
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}
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// Language initialization examples:
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// "eng" - English
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// "fra" - French  
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// "deu" - German
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// "chi_sim" - Simplified Chinese
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// "ara" - Arabic
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// "eng+fra+deu" - Multiple languages
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```
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[Language Support](./language-support.md)
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## Types
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### Core Data Structures
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```java { .api }
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// Progress monitoring and cancellation
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public class ETEXT_DESC {
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    public short progress();           // Progress percentage (0-100)
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    public boolean more_to_come();     // More processing pending
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    public boolean ocr_alive();        // OCR engine active
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    public byte err_code();            // Error code
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    public void set_deadline_msecs(int deadline_msecs);
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    public boolean deadline_exceeded();
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}
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// Unicode character handling
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public class UNICHAR {
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    public UNICHAR(String utf8_str, int len);
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    public UNICHAR(int unicode);
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    public int first_uni();            // Get first character as UCS-4
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    public int utf8_len();             // Get UTF-8 byte length
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    public String utf8_str();          // Get UTF-8 string
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    public static int[] UTF8ToUTF32(String utf8_str);
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    public static String UTF32ToUTF8(int[] str32);
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}
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// Collection types
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public class StringVector {
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    public StringVector();
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    public long size();
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    public String get(long i);
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    public StringVector put(long i, String value);
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    public StringVector push_back(String value);
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    public void clear();
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}
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```
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### Iterator Level Constants
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```java { .api }
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// Page hierarchy levels for iteration
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public static final int RIL_BLOCK = 0;     // Block level
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public static final int RIL_PARA = 1;      // Paragraph level  
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public static final int RIL_TEXTLINE = 2;  // Text line level
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public static final int RIL_WORD = 3;      // Word level
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public static final int RIL_SYMBOL = 4;    // Character/symbol level
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```
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### Block Type Constants
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```java { .api }
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// Layout block types
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public static final int PT_UNKNOWN = 0;        // Unknown block type
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public static final int PT_FLOWING_TEXT = 1;   // Flowing text
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public static final int PT_HEADING_TEXT = 2;   // Heading text
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public static final int PT_PULLOUT_TEXT = 3;   // Pull-out text
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public static final int PT_EQUATION = 4;       // Mathematical equation
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public static final int PT_TABLE = 6;          // Table
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public static final int PT_VERTICAL_TEXT = 7;  // Vertical text
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public static final int PT_CAPTION_TEXT = 8;   // Caption text
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public static final int PT_FLOWING_IMAGE = 9;  // Flowing image
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public static final int PT_NOISE = 14;         // Noise/artifacts
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```