pikasTech / COCR

OCR/OCSR on handwritting ⏣/chemical-structural-formulas with YOLO & CRNN models.

COCR

COCR is designed to convert an image of hand-writing chemical structure to graph of that molecule.

COCR, Optical Character Recognition for Chemical Structures, was once a demo for my undergraduate graduation thesis in 2021.6. It brings OCSR(optical chemical structure recognition) capability into handwriting cases. Below is a summary of supported items.

symbol	strings	ring	solid L	hash L	wavy L	single L	double L	triple L
looks like	(CH2)2COOEt	⏣	▲	△	~~	/	//	///
supported	✔️	✔️	✔️	✔️	✔️	✔️	✔️	✔️

COCR is developed under Qt framework. It handles images with YOLO and CRNN models using opencv or ncnn backend.

In this repository, you can find stable version from release pages. Master branch is under development as it is not robust enough yet.

Features

v1.1

• Add support on strings and wavy bond.

v1.1.on.Ubuntu.mp4

v1.0

Input	Detection	Render

• Support single element symbols: C、H、O、N、P、B、S、F、Cl、Br、I.
• Support bond types: single, double, triple, hash wedge, solid wedge, circle.

Architecture

Flow Chart

Build from source

OpenCV ≥4.5.1, Qt =5.15.2 are required for a minimal build.

git clone https://github.com/xuguodong1999/COCR.git
cd COCR && mkdir build && cd build

cmake .. -G "Ninja" \
  -DQt5_DIR:PATH=path/to/Qt/5.15.2/gcc_64/lib/cmake/Qt5 \
  -DOpenCV_DIR:PATH=path/to/opencv4/lib/cmake/opencv4

cmake --build . --parallel --config Release --target leafxy

Build opencv from source

Build libtorch from source

Data generation

COCR uses SCUT-COUCH2009 as meta handwriting data, and uses QtGui::QTextDocument as rich text renderer.

A chemical structure generator for handwriting cases is written to provider training data for YOLO and CRNN models, which composes meta-character into random chemical structure formulas. You can find related codes under src/data_gen.

After a minimal build above, a data_gen(.exe) can be found under $(BUILD_DIR)/out. There are following usages:

1. Double click or run from shell WITHOUT arguments

this will display samples with cv::imshow

2. Run with -yolo [number of samples] [an empty, existing directory path], for example,

# generate 10 object detection samples under ./yolo/
./data_gen -yolo 10 ./

3. Run with -crnn [number of samples] [an empty, existing directory path], for example,

# generate 10 text recognition samples under ./crnn/
./data_gen -crnn 10 ./

4. Run with -isomer [number of samples] [an empty, existing directory path], for example,

# generate all alkane isomers for C-num ≤ 16 namely {CARBON_NUM}.dat under ./
# dont play with number over 20 without taking a look at src/data_gen/isomers.cpp.
# it may comsume a lot of memory and cpus.
./data_gen -isomer 16 ./

License

GPLv3 Clause