coglyphr: Compute Glyph Centers of Gravity from Image Data

Overview

coglyphr is an R package for computing the center of gravity (COG) of character-like binary images using three different methods. This package provides functions for estimating stroke-based, contour-based, and potential energy-based COG. It is useful for analyzing glyph structure in areas such as visual cognition research and font development.

The current version supports the following COG computation methods:

• Stroke-based COG (cog_stroke)
  
• Contour-based COG (cog_contour), based on the method proposed by Kotani and colleagues (2004, 2011)
  
• Potential energy-based COG (cog_potential), based on the method proposed by Kotani and colleagues (2006)

For details on each function, refer to the function references.

Links

• Documentation: https://mutopsy.github.io/coglyphr/
  
• Source code: https://github.com/mutopsy/coglyphr

Installation

You can install coglyphr from GitHub using devtools:

# Install devtools if not already installed
if (!requireNamespace("devtools", quietly = TRUE)) install.packages("devtools")

# Install coglyphr
devtools::install_github("mutopsy/coglyphr")

Dependencies

This package requires:
* R (>= 4.4.0)
* dplyr
* imager
* sp

Usage

After installation, you can load this package using the library function.

library(coglyphr)

Citation

A paper describing this package has been submitted to the Journal of Open Source Software (JOSS).
Until it is formally published, please cite the following preprint:

Muto, H. (2025). coglyphr: An R package to compute glyph centers of gravity from image data. Jxiv. https://doi.org/10.51094/jxiv.1531

Version History

See the Changelog on pkgdown site for the full changelog.

References

• Kotani, A. (2011). Contour-based evaluation method of center of gravity on characters and its application to font development. Memoirs of Shonan Institute of Technology, 45(1), 23–33. https://shonan-it.repo.nii.ac.jp/records/2000243
• Kotani, A., Asai, Y., Nakamura, Y., Otuka, M., Mituyama, Y., & Onoye, T. (2004). Contour-based evaluation method of center of gravity on “LCFONT.” IPSJ SIG Technical Report, 115, 63–70. https://ipsj.ixsq.nii.ac.jp/records/36793
• Kotani, A., Tanemura, Y., Mitsuyama, Y., Asai, Y., Nakamura, Y., & Onoye, T. (2006). Potential energy-based center of gravity evaluation of characters. The Journal of the Institute of Image Electronics Engineers of Japan, 35(4), 296–305. https://doi.org/10.11371/iieej.35.296