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Read EXIF and other metadata from files

Source: R/exif_read.R
exif_read.Rd

Reads EXIF and other metadata into a data.frame by calling Phil Harvey's ExifTool command-line application.

Usage

exif_read(
  path,
  tags = NULL,
  recursive = FALSE,
  args = NULL,
  quiet = TRUE,
  pipeline = c("json", "csv")
)

Arguments

path

A vector of filenames.

tags

A vector of tags to output. It is a good idea to specify this when reading large numbers of files, as it decreases the output overhead significantly. Spaces will be stripped in the output data frame. This parameter is not case-sensitive.

recursive

TRUE to pass the "-r" option to ExifTool.

args

Additional arguments.

quiet

Use FALSE to display diagnostic information. Default value is TRUE

pipeline

One of "json" (the default) or "csv". Controls whether the exiftool executable, behind the scenes, extracts metadata into a JSON data structure or a tabular csv. The JSON pipeline works well in most cases, but (as documented at https://exiftool.org/exiftool_pod.html) does not properly handle non-UTF-8 character sets. If the metadata fields include characters that are not encoded using UTF-8 and that need to be handled by setting the "-charset" option, use the "csv" pipeline as demonstrated in the second example below.

Value

A data frame of class "exiftoolr" with one row per file processed. The first column, named "SourceFile" gives the name(s) of the processed files. Subsequent columns contain info from the tags read from those files.

Note that binary tags such as thumbnails are loaded as base64-encoded strings that start with "base64:". Although these are truncated in the printed representation of the data.frame returned by the function, they are left unaltered in the data.frame itself.

Details

From the ExifTool website: "ExifTool is a platform-independent Perl library plus a command-line application for reading, writing and editing meta information in a wide variety of files. ExifTool supports many different metadata formats including EXIF, GPS, IPTC, XMP, JFIF, GeoTIFF, ICC Profile, Photoshop IRB, FlashPix, AFCP and ID3, as well as the maker notes of many digital cameras by Canon, Casio, DJI, FLIR, FujiFilm, GE, GoPro, HP, JVC/Victor, Kodak, Leaf, Minolta/Konica-Minolta, Motorola, Nikon, Nintendo, Olympus/Epson, Panasonic/Leica, Pentax/Asahi, Phase One, Reconyx, Ricoh, Samsung, Sanyo, Sigma/Foveon and Sony."

For more information, see the ExifTool website.

References

https://exiftool.org

Examples

if (FALSE) { # \dontrun{
files <- dir(system.file(package = "exiftoolr", "images"),
             pattern = "LaSals|Lizard", full.names = TRUE)
exif_read(files)
exif_read(files, tags = c("filename", "imagesize"))

## Use pipeline="csv" for images needing explicit specification
## and proper handling of a non-default character sets
img_file <- system.file(package = "exiftoolr", "images", "QS_Hongg.jpg")
args <- c("-charset", "exiftool=cp1250")
res <- exif_read(img_file, args = args, pipeline = "csv")
res[["City"]]  ## "Zurich", with an umlaut over the "u"
} # }