To cite package ‘sketcher’ in publications use:

Tsuda H (2021). sketcher: Pencil Sketch Effect. R package version 0.1.3, https://github.com/tsuda16k/sketcher.

Corresponding BibTeX entry:

  @Manual{,
    title = {sketcher: Pencil Sketch Effect},
    author = {Hiroyuki Tsuda},
    year = {2021},
    note = {R package version 0.1.3},
    url = {https://github.com/tsuda16k/sketcher},
  }