How to load/alter image tags from R?

I want to add 'tags' to images by altering their metadata. I think I could use exiftool to start this process but am still unsure of how to go about this. For reference I have a .csv file with the tags I would like to add to images, the .csv file looks something like this:

Now I would like to make it possible to load thing from the 'category' column onto images as metadata, preferably as 'tags' (such that you could see them in programs such as digikam). I'm not sure what the specific code for altering metadata.

I know that is is possible to alter metadata of an image using

exiftool("image.jpg", "Author=John Doe", "Comment=This is a comment") 

but I don't know how to use do this in mass with many images at once.

There are two main packages you can use exifr and exiftoolr. I'm going to use exiftoolr, because it uses system2(), which, unlike system() (used by exifr) is compatible with both Windows and Unix-based computers (e.g. Mac and Linux)

Set-up

First, we install the packages, and get everything up and running:

# if either of these give you errors, install them with install.packages()
library(exiftoolr)
library(tidyverse)

# install exiftool
install_exiftool()

Edit one image

I've downloaded this photo from Wikipedia:

Say we want to change the name of the artist (to play a prank on our friends).

To read the current exif data, we can exif_read() on the file, and we get back a dataframe, which we can select attributes from:

exif_read("/Users/pc/Downloads/Epepeotes_uncinatus_@_Kanjirappally.jpg") %>% select(Artist)
#       Artist
# 1 Praveen. P

Now, to change it, we run exif_call, with our argument(s):

exif_call(args = "-Artist=\"Mark Hill\"", path="/Users/pc/Downloads/Epepeotes_uncinatus_@_Kanjirappally.jpg")
[1] "    1 image files updated"

Now, when we run exif_read() again, the Artist attribute has changed:

exif_read("/Users/pc/Downloads/Epepeotes_uncinatus_@_Kanjirappally.jpg") %>% select(Artist)
#       Artist
#1 "Mark Hill"

Edit many images

To do it many times, I'm going to assume all of the files are in the current working directory.

Loading your dataframe:

df <- data.frame(
  file = c("IMAG0001.JPG", "IMAG0002.JPG"),
  category = c("Human", "Animal")
)

Then, it's simply a matter of looping through the files, applying the things you want to do:

for (i in 1:nrow(df)){
  exif_call(path = image_file_paths[i], args = paste0("-XMP:Category=\"", df$category[i], "\""))
}