OpenCVMarkerPrinter

Description

This small app can save some commonly used opencv markers such as ArUco, ArUcoGrid, Chessboard and ChArUco to vector graphics file. Supported vector graphics file format: .svg, .pdf and .ps.

Dependencies

MarkerPrinter

• numpy
• PIL(Pillow, for image processing)
• cairo(for drawing vector graphic)
• cairosvg(for svg to png)

MarkerPrinterGUI

• tkinter(for GUI)

Installation on Windows

Download from https://www.lfd.uci.edu/~gohlke/pythonlibs/#pycairo the pycairo version 1.19.1 or newer for your python version. (cp38 stands for Python3.8 and amd64 for 64-Bit Version)

Change in requirements the line:

pycairo==1.19.1

to:

pycairo @ file:///[path/of/your/Downloadfolder]/pycairo-1.19.1-cpXX-cpXX-win_amd64.whl

After that install requirements:

python -m pip install -r requirements.txt

Copy from Python installation Path

\Lib\site-packages\cairo\cairo.dll

to:

C:\Windows\System32

Tutorial

GUI

python MarkerPrinterGUI.py

You can switch ArUco, ArUcoGrid, Chessboard and ChArUco mode at the GUI tab, then you can select dictionary from the GUI menu and modify board shape, marker size, border width... etc. at the GUI entry, finally click the preview or save button to show the marker image on the GUI window or save it to file.

Command-Line

Print help

python MarkerPrinter.py

Print predefined dictionary list

python MarkerPrinter.py --list_dictionary

Save chessboard

python MarkerPrinter.py --chess --file "./chess.pdf" --size_x 16 --size_y 9 --square_length 0.09

Save ArUco

python MarkerPrinter.py --aruco --file "./aruco.pdf" --dictionary DICT_ARUCO_ORIGINAL --marker_length 0.07 --marker_id 0 --border_bits 1

Save ArUco Grid

python MarkerPrinter.py --aruco_grid --file "./aruco_grid.pdf" --dictionary DICT_ARUCO_ORIGINAL --size_x 16 --size_y 9 --marker_length 0.07 --marker_separation 0.02 --first_marker 0 --border_bits 1

Save ChArUco

python MarkerPrinter.py --charuco --file "./charuco.pdf" --dictionary DICT_ARUCO_ORIGINAL --size_x 16 --size_y 9 --square_length 0.09 --marker_length 0.07 --border_bits 1

Useful Options:

Divde output to chunks

If you are using consumer level printer, you will suffer from not able printing too large marker, so just set chunks shape at the GUI subSize entry before saving the marker to files, it will divide output marker to chunks. If you are using command-line interface, just add --sub_size_x x --sub_size_y y as parameters.

Page border

If you are printing the image directly, you will need add page border to protect the marker, so just set page border at the GUI pageBorder entry before saving the marker to files. If you are using command-line interface, just add --page_border_x x --page_border_y y as parameters.

Generate aruco data:

Although there is a built-in aruco dictionary data, but if you want to update the dictionary (if aruco update predefined dictionary list), just install opencv-contrib-python (if you installed your enviroment with requirements.txt, it is already installed), and than run

python MarkerPrinter.py --generate arucoDictBytesList.npz