recognizer

• Prerequisite
• Usage
• Examples
• Know issues

This application is used as reference code for developers to show how to use the Python bindings for the C++ API and could be used to easily check the accuracy. The application accepts path to a JPEG/PNG/BMP file as input. This is not the recommended way to use the API. We recommend reading the data directly from the camera and feeding the SDK with the uncompressed YUV data without saving it to a file or converting it to RGB.

If you don't want to build this sample and is looking for a quick way to check the accuracy then, try our cloud-based solution at https://www.doubango.org/webapps/mrz/.

This sample is open source and doesn't require registration or license key.

Prerequisite

You must build the Python extension before trying to run this sample. More information on how to build the extension could be found here

Usage

recognizer.py is a Python command line application with the following usage:

recognizer.py \
      --image <path-to-image-with-mrzdata-to-process> \
      [--assets <path-to-assets-folder>] \
      [--backprop <whether-to-enable-backpropagation:true/false>] \
      [--vcheck <whether-to-enable-vertical-check:true/false>] \
      [--ielcd <whether-to-enable-IELCD:true/false>] \
      [--tokenfile <path-to-license-token-file>] \
      [--tokendata <base64-license-token-data>]

Options surrounded with [] are optional.

• --image Path to the image(JPEG/PNG/BMP) to process. You can use default image at ../../../assets/images/Czech_passport_2005_MRZ_orient1_1300x1002.jpg.
• --assets Path to the assets folder containing the configuration files and models. Default value is the current folder.
• --backprop Whether to enable backpropagation to detect the MRZ lines. More information at https://www.doubango.org/SDKs/mrz/docs/Detection_techniques.html#backpropagation. Default: true for x86 CPUs and false for ARM CPUs.
• --vcheck Whether to enable vertical check to detect +/-90deg rotated images. Default: true for x86 CPUs and false for ARM CPUs.
• --ielcd Whether to enable Image Enhancement for Low Contrast Document (IELCD). More information at https://www.doubango.org/SDKs/mrz/docs/IELCD.html#ielcd. Default: true for x86 CPUs and false for ARM CPUs.
• --tokenfile Path to the file containing the base64 license token if you have one. If not provided then, the application will act like a trial version. Default: null.
• --tokendata Base64 license token if you have one. If not provided then, the application will act like a trial version. Default: null.

Examples

You should navigate to the current folder (ultimateMRZ-SDK/samples/python/recognizer ) before trying the next commands:

cd ultimateMRZ-SDK/samples/python/recognizer

• For example, on Raspberry Pi you may call the recognizer application using the following command:

PYTHONPATH=../../../binaries/raspbian/armv7l:../../../python \
LD_LIBRARY_PATH=../../../binaries/raspbian/armv7l:$LD_LIBRARY_PATH \
python recognizer.py --image ../../../assets/images/Czech_passport_2005_MRZ_orient1_1300x1002.jpg --assets ../../../assets --backprop false --vcheck false --ielcd false

• On Linux x86_64, you may use the next command:

PYTHONPATH=../../../binaries/linux/x86_64:../../../python \
LD_LIBRARY_PATH=../../../binaries/linux/x86_64:$LD_LIBRARY_PATH \
python recognizer.py --image ../../../assets/images/Czech_passport_2005_MRZ_orient1_1300x1002.jpg --assets ../../../assets --backprop true --vcheck true --ielcd true

• On Windows x86_64, you may use the next command:

setlocal
set PYTHONPATH=../../../binaries/windows/x86_64;../../../python
python recognizer.py --image ../../../assets/images/Czech_passport_2005_MRZ_orient1_1300x1002.jpg --assets ../../../assets --backprop true --vcheck true --ielcd true
endlocal

Please note that if you're cross compiling the application then you've to make sure to copy the application and both the assets and binaries folders to the target device.

Know issues

If you get undefined symbol: PyUnicode_FromFormat error message, then make sure you're using Python 3 and same version as the one used to buid the extension. We tested the code on version 3.6.9 (Windows 8), 3.6.8 (Ubuntu 18) and 3.7.3 (Raspbian Buster). Run python --version to print your Python version. You may use python3 instead of python to make sure you're using version 3.