choonkiattay / easyocrgen

Image dataset generator for Optical Character Recognition

EasyOCRGenerator

EasyOCRGenerator is a tools to generate OCR dataset for optical character recognition.

Generator

1. Malaysia license plate
2. Philippine license plate (TODO)
3. English words (TODO)
4. Non lexicon words

Imitator

1. Malaysia license plate

Image augmentation

1. Perspective Transformation
2. Color Inversion
3. Salt & Pepper
4. Singularity: Double line plate Slicer

Notebook

There are logic behind this generator is briefly describe in TightPlateGeneration.ipynb. Singularity research is unfinished.

Dependencies

• OpenCV
• numpy
• imgaug
• pillow
• argparse

Malaysia License Plate

Road Transport Department Malaysia (JPJ) issues various plate layout as below:

Type	Layout
Private & commercial vehicles	ABC 1234 or W/Q/SAB 4567 C
Taxi	HAB 1234
Military	ZA 1234
KL (Transition)	W 1234 A
Diplomatic corps	12-34-DC
Royal & government	(Full title)

Random Plate Generation

This will generate Malaysia plate with the proportion of each plate type stated below:

Layout	Proportion
Priv & Comm, Taxi, Military, KL	85%
Diplomatic corps	10%
Special Plate	5%
Limousine	1%

Please to be reminded the proportion is not based on empirical study but an assumption made for training a good OCR model, that is different plate layout with balance character distribution.

Code

Arguments

• --number Total number plate to generate. Integer
• --mode Generation mode. Use my_plate
• --pers_trans Perspective Transform. On / Off
• --augment Augmentation. On / Off
• --single_line Singularity. On / Off
• --save_dir Directory to save images. Full path directory, Include "/" at EOL

Example

python3 generator.py --number 1000 --mode my_plate --pers_trans on --augment on --single_line on --save_dir /home/user/my_plate/

Plate Imitator

This will read the real license plate image with groundtruth as file name and generate the synthetic version of them.

Code

Arguments

• --imitatee_dir Directory to real plate image. Full path directory, Include "/" at EOL
• --pers_trans Perspective Transform. On / Off
• --augment Augmentation. On / Off
• --single_line Singularity. On / Off
• --save_dir Directory to save images. Full path directory, Include "/" at EOL

Example

python3 imitator_my_plate.py --imitatee_dir /home/user/real_plate/ --pers_trans on --augment on --single_line on --save_dir /home/user/my_plate/

TODO

• Lexicon Word Font & background -> license plate style
• Non lexicon word generation
• Philippine Plate

SideNote

• Singularity research using image processing is not robust at the moment. Fall back to image ratio method.
• Double line license plate generation is blocked now