Tesseract static libraries for MinGW64

Includes a static library linked test program for tesseract in windows with MinGW64 compiler. All static libraries are prebuilt for linking.

Features demonstrated:

• OCR of image
• Output as hocr file
• monitor OCR progress

Credit to:

• MSYS2 (https://msys2.duckdns.org/package/mingw-w64-x86_64-tesseract-ocr?repo=mingw64)

for all the prebuilt libraries except for libtesseract.a and leptonica static libraries

Library:

• Tesseract 4.1.1
• leptonica 1.78.0
• harfbuzz 2.6.4
• and many others the libraries above depend on.

Building Harfbuzz

1. Download the PKGBUILD: https://github.com/msys2/MINGW-packages/tree/master/mingw-w64-harfbuzz
2. In MSYS2:

makepkg-mingw -sCLf

Build Examples

MSYS2 and cmake

cmake -G "MSYS Makefiles" -B build
cd build
make
./CommandLine.exe

Build Options

Compiler

Thread model: posix
gcc version 9.3.0 (Rev1, Built by MSYS2 project)

Tesseract 4.1.1

-- General configuration for Tesseract 4.1.1
-- --------------------------------------------------------
-- Build type: Release
-- Compiler: GNU
-- Used standard: C++17
-- CXX compiler options:  -fopenmp -O3 -DNDEBUG
-- Linker options:
-- Install directory: C:/Program Files (x86)/tesseract
-- Architecture flags: -march=haswell;-msse2;-msse3;-mssse3;-msse4.1;-msse4.2;-mavx;-mfma;-mbmi2;-mavx2;-mno-sse4a;-mno-xop;-mno-fma4;-mno-avx512f;-mno-avx512vl;-mno-avx512pf;-mno-avx512er;-mno-avx512cd;-mno-avx512dq;-mno-avx512bw;-mno-avx512ifma;-mno-avx512vbmi
-- Vector unit list: sse2;sse3;ssse3;sse4.1;sse4.2;avx;fma;bmi2;avx2
-- AVX_OPT: ON
-- AVX2_OPT: ON
-- FMA_OPT: ON
-- SSE41_OPT: ON
-- MARCH_NATIVE_OPT: ON
-- simd_flags:  -DSSE2 -DSSE3 -DSSSE3 -DSSE4_1 -DSSE4_2 -DAVX -DFMA -DBMI2 -DAVX2
-- --------------------------------------------------------
-- Build with cppan [CPPAN_BUILD]: OFF
-- Build with sw [SW_BUILD]: OFF
-- Build with openmp support [OPENMP_BUILD]: 1
-- Disable disable graphics (ScrollView) [GRAPHICS_DISABLED]: OFF
-- Disable the legacy OCR engine [DISABLED_LEGACY_ENGINE]: OFF
-- Build training tools [BUILD_TRAINING_TOOLS]: ON
-- Build tests [BUILD_TESTS]: OFF
-- --------------------------------------------------------
--
-- Found the following ICU libraries:
--   uc (required)
--   i18n (required)
-- Configuring done
-- Generating done

Development Progress

12/22/2019

Dealing with compiling errors:

17:32:17 **** Incremental Build of configuration Debug for project receiptFiler ****
Info: Internal Builder is used for build
g++ "-LC:\\Users\\admin\\eclipse-workspace\\receiptFiler\\lib" -fopenmp -o receiptFiler.exe "src\\receiptFiler.o" "src\\tesseractTest.o" -ltesseract -llept -lopenjp3d -lopenjpwl -lopenmj2 -ljpeg -lpango-1.0 -lpangocairo-1.0 -lpangoft2-1.0 -lpangowin32-1.0 -lharfbuzz-gobject -lharfbuzz-icu -lharfbuzz-subset -lharfbuzz -lcairo -lpixman-1 -lgraphite2 -lglib-2.0 -lgio-2.0 -lgmodule-2.0 -lgobject-2.0 -lgthread-2.0 -ltiff -lgif -lwebp -lasprintf -lcharset -lcrypto -ldatrie -larchive -lexpat -lffi -lfontconfig -lformw -lfribidi -lgettextlib -lgettextpo -lgmp -lgmpxx -lgnurx -lpng -lfreetype -lopenjp2 -lhistory -liconv -licudt -licuin -licuio -licutest -licutu -licuuc -lz -lintl -llcms2 -llzma -lpanelw -lpcre -lpcre16 -lpcre32 -lpcrecpp -lpcreposix -lpng16 -lreadline -lregex -lsqlite3 -lws2_32 -lbz2 -lssl -ltasn1 -lthai -ltre -lturbojpeg -lzstd -llzo2 -lmenuw -lmpc -lmpdec -lmpfr -lncurses -lncurses++w -lncurses++w_g -ltiffxx -ltkstub86 -lwebpdecoder -lwebpdemux -lwebpmux -lncursesw -lncursesw_g -lbcrypt -lsystre -lole32 -lwinmm -lshlwapi -lstdc++ -luser32 -lkernel32 -lgdi32 -lcomdlg32 -lpsapi -lwsock32 -lhogweed -lnettle -llz4 -lm 
C:\Users\admin\eclipse-workspace\receiptFiler\lib/liblept.a(utils1.o):(.text+0x1253): undefined reference to `__imp__difftime64'
C:\Users\admin\eclipse-workspace\receiptFiler\lib/liblept.a(jp2kio.o):(.text+0x17a): undefined reference to `__imp_opj_stream_create'
C:\Users\admin\eclipse-workspace\receiptFiler\lib/liblept.a(jp2kio.o):(.text+0x195): undefined reference to `__imp_opj_stream_set_user_data'
C:\Users\admin\eclipse-workspace\receiptFiler\lib/liblept.a(jp2kio.o):(.text+0x1c8): undefined reference to `__imp_opj_stream_set_user_data_length'
C:\Users\admin\eclipse-workspace\receiptFiler\lib/liblept.a(jp2kio.o):(.text+0x1d8): undefined reference to `__imp_opj_stream_set_read_function'
C:\Users\admin\eclipse-workspace\receiptFiler\lib/liblept.a(jp2kio.o):(.text+0x1e8): undefined reference to `__imp_opj_stream_set_write_function'
C:\Users\admin\eclipse-workspace\receiptFiler\lib/liblept.a(jp2kio.o):(.text+0x1f8): undefined reference to `__imp_opj_stream_set_skip_function'
C:\Users\admin\eclipse-workspace\receiptFiler\lib/liblept.a(jp2kio.o):(.text+0x208): undefined reference to `__imp_opj_stream_set_seek_function'
C:\Users\admin\eclipse-workspace\receiptFiler\lib/liblept.a(jp2kio.o):(.text+0x348): undefined reference to `__imp_opj_version'
C:\Users\admin\eclipse-workspace\receiptFiler\lib/liblept.a(jp2kio.o):(.text+0x61f): undefined reference to `__imp_opj_image_create'
C:\Users\admin\eclipse-workspace\receiptFiler\lib/liblept.a(jp2kio.o):(.text+0x7ba): undefined reference to `__imp_opj_set_default_encoder_parameters'
C:\Users\admin\eclipse-workspace\receiptFiler\lib/liblept.a(jp2kio.o):(.text+0x80c): undefined reference to `__imp_opj_create_compress'
C:\Users\admin\eclipse-workspace\receiptFiler\lib/liblept.a(jp2kio.o):(.text+0x83a): undefined reference to `__imp_opj_setup_encoder'
C:\Users\admin\eclipse-workspace\receiptFiler\lib/liblept.a(jp2kio.o):(.text+0x871): undefined reference to `__imp_opj_start_compress'
C:\Users\admin\eclipse-workspace\receiptFiler\lib/liblept.a(jp2kio.o):(.text+0x885): undefined reference to `__imp_opj_encode'
C:\Users\admin\eclipse-workspace\receiptFiler\lib/liblept.a(jp2kio.o):(.text+0x899): undefined reference to `__imp_opj_end_compress'
C:\Users\admin\eclipse-workspace\receiptFiler\lib/liblept.a(jp2kio.o):(.text+0x8a4): undefined reference to `__imp_opj_stream_destroy'
C:\Users\admin\eclipse-workspace\receiptFiler\lib/liblept.a(jp2kio.o):(.text+0x8ad): undefined reference to `__imp_opj_destroy_codec'
C:\Users\admin\eclipse-workspace\receiptFiler\lib/liblept.a(jp2kio.o):(.text+0x8b8): undefined reference to `__imp_opj_image_destroy'
C:\Users\admin\eclipse-workspace\receiptFiler\lib/liblept.a(jp2kio.o):(.text+0x9c5): undefined reference to `__imp_opj_destroy_codec'
C:\Users\admin\eclipse-workspace\receiptFiler\lib/liblept.a(jp2kio.o):(.text+0x9d0): undefined reference to `__imp_opj_image_destroy'
C:\Users\admin\eclipse-workspace\receiptFiler\lib/liblept.a(jp2kio.o):(.text+0xa1f): undefined reference to `__imp_opj_set_info_handler'
C:\Users\admin\eclipse-workspace\receiptFiler\lib/liblept.a(jp2kio.o):(.text+0xa32): undefined reference to `__imp_opj_set_warning_handler'
C:\Users\admin\eclipse-workspace\receiptFiler\lib/liblept.a(jp2kio.o):(.text+0xa45): undefined reference to `__imp_opj_set_error_handler'
C:\Users\admin\eclipse-workspace\receiptFiler\lib/liblept.a(jp2kio.o):(.text+0xb95): undefined reference to `__imp_opj_stream_destroy'
C:\Users\admin\eclipse-workspace\receiptFiler\lib/liblept.a(jp2kio.o):(.text+0xb9e): undefined reference to `__imp_opj_destroy_codec'
C:\Users\admin\eclipse-workspace\receiptFiler\lib/liblept.a(jp2kio.o):(.text+0xba9): undefined reference to `__imp_opj_image_destroy'
C:\Users\admin\eclipse-workspace\receiptFiler\lib/liblept.a(jp2kio.o):(.text+0xc15): undefined reference to `__imp_opj_stream_destroy'
C:\Users\admin\eclipse-workspace\receiptFiler\lib/liblept.a(jp2kio.o):(.text+0xc1e): undefined reference to `__imp_opj_destroy_codec'
C:\Users\admin\eclipse-workspace\receiptFiler\lib/liblept.a(jp2kio.o):(.text+0xc29): undefined reference to `__imp_opj_image_destroy'
C:\Users\admin\eclipse-workspace\receiptFiler\lib/liblept.a(jp2kio.o):(.text+0xc75): undefined reference to `__imp_opj_destroy_codec'
C:\Users\admin\eclipse-workspace\receiptFiler\lib/liblept.a(jp2kio.o):(.text+0xc80): undefined reference to `__imp_opj_image_destroy'
C:\Users\admin\eclipse-workspace\receiptFiler\lib/liblept.a(jp2kio.o):(.text+0xcc7): undefined reference to `__imp_opj_image_destroy'
C:\Users\admin\eclipse-workspace\receiptFiler\lib/liblept.a(jp2kio.o):(.text+0xd78): undefined reference to `__imp_opj_version'
C:\Users\admin\eclipse-workspace\receiptFiler\lib/liblept.a(jp2kio.o):(.text+0xdec): undefined reference to `__imp_opj_set_default_decoder_parameters'
C:\Users\admin\eclipse-workspace\receiptFiler\lib/liblept.a(jp2kio.o):(.text+0xe21): undefined reference to `__imp_opj_create_decompress'
C:\Users\admin\eclipse-workspace\receiptFiler\lib/liblept.a(jp2kio.o):(.text+0xe4a): undefined reference to `__imp_opj_setup_decoder'
C:\Users\admin\eclipse-workspace\receiptFiler\lib/liblept.a(jp2kio.o):(.text+0xe7f): undefined reference to `__imp_opj_read_header'
C:\Users\admin\eclipse-workspace\receiptFiler\lib/liblept.a(jp2kio.o):(.text+0xede): undefined reference to `__imp_opj_set_decode_area'
C:\Users\admin\eclipse-workspace\receiptFiler\lib/liblept.a(jp2kio.o):(.text+0xefa): undefined reference to `__imp_opj_decode'
C:\Users\admin\eclipse-workspace\receiptFiler\lib/liblept.a(jp2kio.o):(.text+0xf0e): undefined reference to `__imp_opj_end_decompress'
C:\Users\admin\eclipse-workspace\receiptFiler\lib/liblept.a(jp2kio.o):(.text+0xf1f): undefined reference to `__imp_opj_stream_destroy'
C:\Users\admin\eclipse-workspace\receiptFiler\lib/liblept.a(jp2kio.o):(.text+0xf28): undefined reference to `__imp_opj_destroy_codec'
C:\Users\admin\eclipse-workspace\receiptFiler\lib/liblept.a(jp2kio.o):(.text+0x1201): undefined reference to `__imp_opj_stream_destroy'
C:\Users\admin\eclipse-workspace\receiptFiler\lib/liblept.a(jp2kio.o):(.text+0x120a): undefined reference to `__imp_opj_destroy_codec'
C:\Users\admin\eclipse-workspace\receiptFiler\lib/liblept.a(jp2kio.o):(.text+0x1218): undefined reference to `__imp_opj_image_destroy'
C:\Users\admin\eclipse-workspace\receiptFiler\lib/liblept.a(jp2kio.o):(.text+0x124a): undefined reference to `__imp_opj_image_destroy'
C:\Users\admin\eclipse-workspace\receiptFiler\lib/liblept.a(jp2kio.o):(.text+0x1262): undefined reference to `__imp_opj_set_info_handler'
C:\Users\admin\eclipse-workspace\receiptFiler\lib/liblept.a(jp2kio.o):(.text+0x1275): undefined reference to `__imp_opj_set_warning_handler'
C:\Users\admin\eclipse-workspace\receiptFiler\lib/liblept.a(jp2kio.o):(.text+0x1288): undefined reference to `__imp_opj_set_error_handler'
C:\Users\admin\eclipse-workspace\receiptFiler\lib/liblept.a(jp2kio.o):(.text+0x12a5): undefined reference to `__imp_opj_destroy_codec'
C:\Users\admin\eclipse-workspace\receiptFiler\lib/liblept.a(jp2kio.o):(.text+0x12c5): undefined reference to `__imp_opj_destroy_codec'
C:\Users\admin\eclipse-workspace\receiptFiler\lib/liblept.a(jp2kio.o):(.text+0x12d1): undefined reference to `__imp_opj_stream_destroy'
C:\Users\admin\eclipse-workspace\receiptFiler\lib/liblept.a(jp2kio.o):(.text+0x12df): undefined reference to `__imp_opj_image_destroy'
C:\Users\admin\eclipse-workspace\receiptFiler\lib/liblept.a(jp2kio.o):(.text+0x130f): undefined reference to `__imp_opj_destroy_codec'
C:\Users\admin\eclipse-workspace\receiptFiler\lib/libharfbuzz.a(libharfbuzz_la-hb-directwrite.o):(.text+0x183): undefined reference to `__imp_DWriteCreateFactory'
C:\Users\admin\eclipse-workspace\receiptFiler\lib/libharfbuzz.a(libharfbuzz_la-hb-uniscribe.o):(.text+0x33a): undefined reference to `__imp_UuidCreate'
collect2.exe: error: ld returned 1 exit status

leptonica library is looking for dynamic libraries when static needs to be found. Harfbuzz library seems to be having the same issue, but not confirmed.

Solution

https://cloud.tencent.com/developer/article/1433585

Recompile leptonica and harfbuzz with macro definitions to indicate it will be linked statically.

12/22/2019

The solution above was correct. Leptonica had a make file in its src directory allowing it to be build a static library when invoked by MSYS2. Used MSYS2 to use PKGBUILD to make static harfbuzz. https://github.com/msys2/MINGW-packages/tree/master/mingw-w64-harfbuzz

3/1/2020

Using cmake now intead of eclipse.

3/21/2020

• Compiled libtesseract.a
• Removed the version by Alexpux (https://github.com/msys2/MINGW-packages)

Investigating slow OCR recognize

After investigating possible reasons why the OCR processing is so slow with this library, two different OCR engines were discovered:

• legacy
• LSTM

The legacy engine is much faster. This library uses LSTM which is believed to be more accurate, but slower. The CPU extensions and instructions also were already present and enabling the compiler flags did not help the performance:

• AVX extensions -mavx2
• SSE4a instruction set -msse4a

It's possible that this library is slow because it uses LSTM engine and others have used the old engine, giving them a false impression there is an issue with this library. The performance profile below shows LSTM engine with AVX extensions for Matrices being used. In the future OpenCL may help make these matrix multiplications faster.

Performance Profile with AQTime 8

Routine Name	Time	Time with Children	Shared Time	Hit Count
tesseract::LSTM::Forward	20.26	26.15	77.48	472
tesseract::DotProductAVX	20.11	20.11	100.00	175187512
tesseract::FullyConnected::Forward	7.02	8.25	85.15	236
const tesseract::WeightMatrix::MatrixDotVector	6.21	26.32	23.59	3834140

Sources:

• tesseract-ocr/tesseract#1307
• https://www.gitmemory.com/issue/tesseract-ocr/tesseract/2611/520371088