resmush

resmush is a R package that allow users to optimize and compress images using reSmush.it. reSmush.it is a free API that provides image optimization, and it has been implemented on WordPress, Drupal and many more.

Some of the features of reSmush.it are:

• Free optimization services, no API key required.
• Optimize local and online images.
• Image files supported: png, jpg/jpeg, gif, bmp, tiff.
• Max image size: 5 Mb.
• Compression via several algorithms:
  • PNGQuant: Strip unneeded chunks from pngs, preserving a full alpha transparency.
  • JPEGOptim: Lossless optimization based on optimizing the Huffman tables.
  • OptiPNG: png reducer that is used by several online optimizers.

Installation

Install resmush from CRAN with:

install.packages("resmush")

You can install the development version of resmush from GitHub with:

remotes::install_github("dieghernan/resmush")

Alternatively, you can install resmush using the r-universe+:

# Install resmush in R:
install.packages("resmush", repos = c(
  "https://dieghernan.r-universe.dev",
  "https://cloud.r-project.org"
))

Example

Compressing an online jpg image:

library(resmush)

url <- paste0(
  "https://raw.githubusercontent.com/dieghernan/",
  "resmush/main/img/jpg_example_original.jpg"
)

resmush_url(url, outfile = "man/figures/jpg_example_compress.jpg", overwrite = TRUE)
#> ══ resmush summary ═════════════════════════════════════════════════════════════
#> ℹ Input: 1 url with size 178.7 Kb
#> ✔ Success for 1 url: Size now is 45 Kb (was 178.7 Kb). Saved 133.7 Kb (74.82%).
#> See result in directory 'man/figures'.

The quality of the compression can be adjusted in the case of jpg files using the parameter qlty. However, it is recommended to keep this value above 90 to get a good image quality.

# Extreme case
resmush_url(url,
  outfile = "man/figures/jpg_example_compress_low.jpg", overwrite = TRUE,
  qlty = 3
)
#> ══ resmush summary ═════════════════════════════════════════════════════════════
#> ℹ Input: 1 url with size 178.7 Kb
#> ✔ Success for 1 url: Size now is 2.2 Kb (was 178.7 Kb). Saved 176.4 Kb (98.74%).
#> See result in directory 'man/figures'.

All the functions return invisibly a data set with a summary of the process. The next example shows how when compressing a local file.

png_file <- system.file("extimg/example.png", package = "resmush")

# For the example, copy to a temporary file
tmp_png <- tempfile(fileext = ".png")
file.copy(png_file, tmp_png, overwrite = TRUE)
#> [1] TRUE


summary <- resmush_file(tmp_png, overwrite = TRUE)

tibble::as_tibble(summary[, -c(1, 2)])
#> # A tibble: 1 × 6
#>   src_size dest_size compress_ratio notes src_bytes dest_bytes
#>   <chr>    <chr>     <chr>          <chr>     <dbl>      <dbl>
#> 1 239.9 Kb 70.7 Kb   70.54%         OK       245618      72356

Other alternatives

There are other alternatives for optimizing images with R:

• xfun (Xie 2024), which includes the following functions for optimizing image files:
  • xfun::tinify() is similar to resmush_file() but uses TinyPNG. An API key is required.
  • xfun::optipng() compresses local files with OptiPNG (which needs to be installed locally).
• tinieR package by jmablog. An R package that provides a full interface with TinyPNG.
• optout package by @coolbutuseless. Similar to xfun::optipng() with more options. Requires additional software to be installed locally.

Table 1: R packages: Comparison of alternatives for optimizing images.

Table 2: R packages: Formats admitted.

Citation

Hernangómez D (2024). resmush: Optimize and Compress Image Files with reSmush.it. doi:10.32614/CRAN.package.resmush, https://dieghernan.github.io/resmush/.

A BibTeX entry for LaTeX users is

@Manual{R-resmush,
  title = {{resmush}: Optimize and Compress Image Files with {reSmush.it}},
  doi = {10.32614/CRAN.package.resmush},
  author = {Diego Hernangómez},
  year = {2024},
  version = {0.2.0},
  url = {https://dieghernan.github.io/resmush/},
  abstract = {Compress local and online images using the reSmush.it API service <https://resmush.it/>.},
}

References