camtrapR not accepting the date & time in our images

Tom D

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Oct 31, 2017, 10:25:02 AM10/31/17

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Hi Jürgen,

We’re just doing a small camera trap study, for which your excellent cameratrapR package seems the perfect analysis tool. Though we are having some problems getting the package to read the date & time from our image.

I’ve tagged all 4000 of our sample images in digiKam, but don’t seem to be able to get the package to accept the images – whenever I try to do a timeshift or recordTable errors appear (below). The images are stored at e.g. G:\rawImages\stationA\camera1 and the code I used is below:

testimages <- ("G:/test")

## image shift time

timeShiftTabletest = read.csv("timeShiftTable_test.csv")

timeshift_run <- timeShiftImages(inDir )

timeshift_run = testimages,

timeShiftTable = timeShiftTabletest,

stationCol = "station",

hasCameraFolders = TRUE,

cameraCol = "camera",

timeShiftColumn = "timeshift",

timeShiftSignColumn = "sign"

Which results in the following:

G:/rawImages/stationA/camera1

Warning messages:

1: running command 'exiftool -r "-DateTimeOriginal+=0:0:0 0:0:1" "G:/rawImages/stationA/camera1"' had status 1

> timeshift_run

1 G:/rawImages/stationA/camera1 0 image files updated

1 8 files weren't updated due to errors

Similarly, after when trying to export the data, the following happens:

export <- recordTable(inDir = images,

IDfrom = "metadata",

metadataSpeciesTag = "Species",

stationCol = "station",

camerasIndependent = F,

cameraID = "directory",

)

Warning: timeZone is not specified. Assuming UTC

stationA : 117 images

Error in `$<-.data.frame`(`*tmp*`, "DateTimeOriginal", value = numeric(0)) :

replacement has 0 rows, data has 117

I’ve attached an image, one of our 4000 camera trap images that causes the above errors. Could you please help us get the images into a form the package will find acceptable as input?

Best regards,

Tom

IMAG0001.JPG

Tom D

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Nov 6, 2017, 3:22:27 PM11/6/17

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Hi Jurgen, it seems I uploaded some strange image with no datetime. Here is another one that should make it possible to answer the question.

Tagged - not working.jpg

Juergen Niedballa

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Nov 7, 2017, 12:18:27 AM11/7/17

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Hi Tom,

the second picture also does not contain date and time. I suspect that in uploading to the google group the image is stripped of its metadata.

To answer the question, the errors arose because images don't store the date/time tag correctly (telling from images emailed to me, not the images uploaded to the google group). The date/time information is not in the Exif metadata slot DateTimeOriginal, but instead in XMP:DateTimeOriginal. This can be checked with exiftool like this (the -G argument makes exiftool return the tag group name):

exiftool -G "C:\Path\to\your\images\Tagged - not working.jpg"

I don't know how and why this happened. It is weird because it should be saved in the right place by default (except for some specific reconyx camera models).

Anyways, here is a method for fixing this problem. Please be sure to make a backup first. And replace "C:\Path\to\your\images" with the path to your images (only the images with this date/time problem!). Run the lines beginning with exiftool in the command line (cmd.exe in Windows)

1. Fix the metadata problems (this does not yet work on the DateTimeOriginal tag)

exiftool -all= -tagsfromfile @ -all:all -unsafe -icc_profile "C:\Path\to\your\images"

2. Create an Exif:DateTimeOriginal tag from the XMP:DateTimeOriginal tag

exiftool "-EXIF:DateTimeOriginal<XMP:DateTimeOriginal" "C:\Path\to\your\images"

# then delete the jpg_original files if the result is ok (manually or with this line)

exiftool -delete_original "C:\Path\to\your\images"

For 4000 images it may take a while.
If you want to run it recursively (including all subdirectories of the directory you give, add "-r", e.g.:

exiftool -all= -tagsfromfile @ -all:all -unsafe -icc_profile -r "C:\Path\to\your\images"

Best regards,

Jürgen

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