oneocr-api

The Java FFM binding to the OCR engine built into the Windows 11 Snipping Tool. No JNI, nothing to compile.

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Requirements

• JDK 22+ (recommended - FFM is final, no preview flags needed)
• JDK 21 (alternative - FFM is preview, requires --enable-preview; for building use -P build-jdk21)
• Windows 11 with SnippingTool

Build

# JDK 22+ (recommended)
mvn clean package

# JDK 21 (requires preview features)
mvn clean package -P build-jdk21

Usage (API)

# JDK 22+
java --enable-native-access=oneocr.api -jar target/oneocr-api-2.0.jar

# JDK 21
java --enable-preview --enable-native-access=oneocr.api -jar target/oneocr-api-1.0-jdk21.jar

Testing

# Performance comparison (auto-detects JDK versions)
java TestJDK21JDK22Plus.java

# Simple test
java --enable-native-access=oneocr.api -cp "target/classes;target/test-classes" oneocr.api.test.SimpleOcrTest

Native Libraries Setup (Development)

For development, extract from C:\Program Files\WindowsApps\Microsoft.ScreenSketch_11.<version>_x64__8wekyb3d8bbwe\SnippingTool (e.g., C:\Program Files\WindowsApps\Microsoft.ScreenSketch_11.2409.25.0_x64__8wekyb3d8bbwe\SnippingTool):

• oneocr.dll
• oneocr.onemodel
• onnxruntime.dll
• opencv_world4120.dll

Copy to src/main/resources/natives/ folder.

Extraction Notes: WindowsApps folder is owned by TrustedInstaller. To extract files:

1. Take ownership temporarily (right-click folder → Properties → Security → Advanced → Change → enter your username)
2. Copy required DLL files to src/main/resources/natives/
3. CRITICAL: Restore ownership to TrustedInstaller ( Warning: Improper ownership changes can break Windows Store apps. See proper reference such as : WindowsApps Permissions Guide )

Runtime Behavior

At runtime, native libraries are automatically extracted to <userhome>/oneocr/ and loaded. Built JARs include all dependencies.

Design: This API module provides portable, bare-minimum OCR functionality for building custom applications. For ready-to-use command-line tools, see the Tools module.

Related

• Tools: oneocr-cli
• Original: win11-oneocr