How to trim a picture with rmarkdown/html?

Question

I want to include a picture form the web in my markdown document, but I just want the left part of the picture. I searched on how to trim picture with rmarkdown but I found nothing...

Here is an example

---
title: "How to trim?"
output: html_document
---

```{r setup, include=FALSE}
library(knitr)
knitr::opts_chunk$set(echo = TRUE, fig.align = 'center')
```

Include picture

```{r pic}
include_graphics("http://ggplot2.tidyverse.org/README-example-1.png")
```

which gave me this HTML output.

If I want to trim the legend (the ~20% right part), how can I do?

I accept any type of answer: relative or absolute specifiation, rmarkdown or html solution, ...

Thanks!

Answer 1

You can use:

library(magick)
crop <- function(im, left = 0, top = 0, right = 0, bottom = 0) {
  d <- dim(im[[1]]); w <- d[2]; h <- d[3]
  image_crop(im, glue::glue("{w-left-right}x{h-top-bottom}+{left}+{top}"))
}
"http://ggplot2.tidyverse.org/README-example-1.png" %>%
  image_read() %>%
  crop(right = 210)

Answer 2

Thanks to @hrbrmstr comment, I found a solution.

library(magick)
library(magrittr)
image_read("http://ggplot2.tidyverse.org/README-example-1.png") %>% 
  image_flop() %>% 
  image_crop("1344x960+250") %>% 
  image_flop()

I'm not sure it's the most efficient with the two image_flop() functions and I don't understand precisly the "1344x960+250" but it works :)