Using resmush"

In resmush: Optimize and Compress Image Files with 'reSmush.it'

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 or Magento.

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.

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 = "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 '.'.

::: figure {alt="Original uncompressed file" width="100%"}

{alt="Optimized file" width="100%"}

Original picture (top) 178.7 Kb and optimized picture (bottom) 45 Kb (Compression 74.8%). Click to enlarge.

:::

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 = "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 '.'.

::: figure {width="100%"}

Low quality image due to a high compression rate.

:::

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)

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 [@xfun], 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.

| tool | CRAN | Additional software? | Online? | API Key? | Limits? | |-------------|-------------|-------------|-------------|-------------|-----------------| | xfun::tinify() | Yes | No | Yes | Yes | 500 files/month (Free tier) | | xfun::optipng() | Yes | Yes | No | No | No | | tinieR | No | No | Yes | Yes | 500 files/month (Free tier) | | optout | No | Yes | No | No | No | | resmush | Yes | No | Yes | No | Max size 5Mb |

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

| tool | png | jpg | gif | bmp | tiff | webp | pdf | |-------------------|-----|-----|-----|-----|------|------|-----| | xfun::tinify() | ✅ | ✅ | ❌ | ❌ | ❌ | ✅ | ❌ | | xfun::optipng() | ✅ | ❌ | ❌ | ❌ | ❌ | ❌ | ❌ | | tinieR | ✅ | ✅ | ❌ | ❌ | ❌ | ✅ | ❌ | | optout | ✅ | ✅ | ❌ | ❌ | ❌ | ❌ | ✅ | | resmush | ✅ | ✅ | ✅ | ✅ | ✅ | ❌ | ❌ |

: Table 2: R packages: Formats admitted.

References

resmush documentation built on April 4, 2025, 4:13 a.m.