camtrapR (version 0.97.0)

checkSpeciesFolders: Consistency check on species photograph identification

Description

This function assesses possible misidentification of species or mistakes in moving images to species directories. Within each station and for all images of each species, it assesses whether there are images taken within a given time interval in other species directories. Often it is unlikely that different species are encountered within a very short time intervals at the same location. This type of misidentification can arise easily if some images belonging to a sequence are moved into different species directories.

Usage

checkSpeciesFolders(inDir, 
  maxDeltaTime, 
  exclude,
  writecsv = FALSE
)

Arguments

inDir

chraracter. Directory containing station subdirectories, which in turn contain renamed and identified images in species subdirectories (e.g. inDir/Station1/SpeciesA)

maxDeltaTime

numeric. Maximum time interval between images to be returned (in seconds)

exclude

character. vector of species directories to exclude from check

writecsv

logial. Should the resulting data.frame be saved as a .csv?

Value

• A data.frame listing all images with their file names, directory and time stamp that were taken within a certain time of another species image at a particular station.

Details

Images may accidentally be moved into wrong directories when identifying species by moving images into directories. Imagine your camera takes 3 shots every time it is triggered and you move those three images into different species directories. The time difference will be very small (e.g. a few seconds). This function will return all these images for you to check. Directories like "blank" or "team" can be ignored using exclude.

Examples

wd_images_ID <- system.file("pictures/sample_images", package = "camtrapR")

maxTimeDiff <- 120   # = 2 minutes

 if (Sys.which("exiftool") != ""){        # only run this example if Exiftool is available
check.folders <- checkSpeciesFolders(inDir = wd_images_ID,
  maxDeltaTime = maxTimeDiff,
  writecsv = FALSE)
                                     
check.folders   
# In this example, these are really 2 different species photographed within 2 minutes. 
}