Cassette collection. Photo by Jametlene Reskp. Introduction Dealing with large-scale image outputs in R packages can be challenging, especially when it comes to passing CRAN checks. In this post, I will share my experience in using pngquant and ragg to compress the PNG output size for readme and vignettes. This allows R packages with many figures in their documentation to pass the CRAN checks without compromising image quality. Problem description I encountered a problem with my package, ggsci, which outputs approximately 30 example figures from both vignettes and …