Compute Glyph Centers of Gravity from Image Data

Computes 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 contour-based method was originally proposed by Kotani et al. (2004) < https://ipsj.ixsq.nii.ac.jp/records/36793> and Kotani (2011) < https://shonan-it.repo.nii.ac.jp/records/2000243>, while the potential energy-based method was introduced by Kotani et al. (2006) .

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

• CRAN: https://CRAN.R-project.org/package=coglyphr
• Documentation: https://mutopsy.github.io/coglyphr/
• Source code: https://github.com/mutopsy/coglyphr

Installation

The stable release of coglyphr is available on CRAN:

install.packages("coglyphr")

You can also install the development version from GitHub:

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

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

Dependencies

Required

• R (>= 4.4.0)
• dplyr
• sp

Optional

• imager
  Required only when using image objects of class cimg or when returning results as cimg.
• png, jpeg, tiff, bmp
  Required only for reading image files of the corresponding formats.

Usage

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

library(coglyphr)

Citation

Please cite the following preprint when using this package. Although this work is released as a preprint, it represents the final version and will not be submitted elsewhere.

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