Java JNI wrapper for GNU OCRAD

This project uses GNU OCRAD to perform OCR using java.

Getting Started

Supports PNM(PBM,PPM,..etc) formats for now.

Prerequisites

Java 1.8 32 bit (64 bit doesn't work)

Runnig project

• Import this project into Eclipse.
• Add dll path to Native library location.
• Run Ocrad.java , the test image file is located in resources/test.pbm.
• It should print

0.26
00123456789
ABCDEFGHIJKLMN
ÑOPQRSTUVWXYZ
abcdefghijklmn
ñopqrstuvwxyz
ÁÉÍÓÚ ÀÈÌÒÙ ÄËÏÖÜ
ÂÊÎÔÛ ??´ å¨ý
áéíóú àèìòù äëïöü âêîôû
!"#$%&'()*+,-./:;<=>?
@[\]^_`{|}~¡ª¬°

Development

If you just want to compile the library for linux skip this step and go to Compiling step.

Generate header file

• Add external tools configuration to generate header file.

• Enter the configuration as provided below the image.

• Program -> Right click -> New Configuration

• Location: C:\Program Files\Java\jdk1.8.0_102\bin\javah.exe

• Working Directory: ${workspace_loc:/${project_name}/src}

• Arguments:

-classpath ${project_classpath} -v -d ${workspace_loc:/${project_name}/src/main/resources} ${java_type_name}

• Select Main.java file and then click run external tools JNI.
• The header file will be generated in JOCRAD\src\main\resources\ as com_ocrad_Main.h

Implementation of com_ocrad_Main.h

The basic functions of ocradlib were implemented in com_ocrad_Main.cc file.

Compiling

Precompiled dll already available for Windows in src/main/resources/dll folder, if you want to compile for linux please get the following repository

https://github.com/t-pankajkumar/OCRAD

Steps to compile

• Generate object files of ocradlib follow the instructions @ https://github.com/t-pankajkumar/OCRAD/blob/master/INSTALL
• Compile jni implimentation g++ -c -fPIC -I"C:/Program Files/Java/jdk1.8.0_102/include" -I"C:/Program Files/Java/jdk1.8.0_102/include/win32" com_ocrad_Main.cc -o com_ocrad_Main.o
• Generate dll g++ -shared -o native.so com_ocrad_Main.o common.o segment.o mask.o rational.o rectangle.o track.o iso_8859.o ucs.o user_filter.o page_image.o page_image_io.o bitmap.o blob.o profile.o feats.o feats_test0.o feats_test1.o character.o character_r11.o character_r12.o character_r13.o textline.o textline_r2.o textblock.o textpage.o -Wl,--add-stdcall-alias
• Move the generated native.so to src/main/resources/dll.
• Run Ocrad.java.
• BINGO