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back File metadata

Upload metadata to add information that can't be extracted from the files.

BIIGLE supports metadata like the date and time of creation or the geo coordinates of a file. Every time a new image volume is created, BIIGLE attempts to automatically read the metadata from the EXIF information of JPEG files. This doesn't work for videos or if the images have another format than JPEG.

In this case you can upload a metadata file. BIIGLE supports the iFDO standard for import of the metadata fields described below. Additionally, there is a custom CSV format for metadata import. The CSV file should use , as delimiter, " as enclosure and \ as escape characters. Please note the additional explanation of video metadata below. The following columns are supported (multiple synonyms exist for some colums, including the standard proposed in [1]):

Column Description
filename
file

The name of the file the metadata belongs to.

This column is mandatory.
taken_at
SUB_datetime
The date and time where the file was taken. Example: 2016-12-19 12:49:00
lng
lon
longitude
SUB_longitude
Longitude where the file was taken in decimal form. If this column is present, lat must be present, too. Should be in the EPSG:4326 coordinate reference system. Example: 52.3211
lat
latitude
SUB_latitude
Latitude where the file was taken in decimal form. If this column is present, lng must be present, too. Should be in the EPSG:4326 coordinate reference system. Example: 28.775
gps_altitude
SUB_altitude
Altitude where the file was taken in meters. Negative for below sea level. Example: -1500.5
distance_to_ground
SUB_distance
Distance to the sea floor in meters. Example: 30.25
area Area shown by the file in square meters. Example: 2.6
yaw
SUB_heading
The yaw/heading in degrees of the underwater vehicle. 0° yaw should be north, 90° east. Example: 180

Example:

filename,taken_at,lng,lat,gps_altitude,distance_to_ground,area
image_1.png,2016-12-19 17:09:00,52.112,28.001,-1500.5,30.25,2.6
image_2.png,2016-12-19 17:09:31,52.215,28.501,-1502.5,28.25,2.1

The metadata CSV file can be uploaded when a new volume is created. For existing volumes, metadata can be uploaded by volume admins on the volume edit page that you can reach with the button of the volume overview.

Video metadata

Video metadata can be imported in the "basic" or the "timestamped" form. The basic form is equivalent to image metadata where a video file can have at most one entry in the metadata CSV file. The timestamped form requires the taken_at column and allows to import many metadata values for different times of the same video. To import timestamped video metadata, add multiple rows with the same filename but different taken_at timestamp to the metadata CSV. Metadata will be ordered by timestamp and the earliest timestamp will be assumed to mark the beginning of the video.

Example:

filename,taken_at,lng,lat,gps_altitude,distance_to_ground,area
video_1.mp4,2016-12-19 17:09:00,52.112,28.001,-1500.5,30.25,2.6
video_1.mp4,2016-12-19 17:10:00,52.122,28.011,-1505.5,25.0,5.5

Video metadata can be updated using the metadata upload of the volume edit page. Videos having "basic" metadata cannot be updated with "timestamped" metadata and vice versa. Timestamped metadata is merged with the information of the new CSV file if the taken_at timestamps of a video do not match exactly. For example, if a video already has the metadata of the example CSV shown above and now the following metadata file is uploaded:

filename,taken_at,lng,lat
video_1.mp4,2016-12-19 17:09:00,52.115,28.003
video_1.mp4,2016-12-19 17:09:30,52.118,28.005

The metadata of the video will be merged as follows:

filename,taken_at,lng,lat,gps_altitude,distance_to_ground,area
video_1.mp4,2016-12-19 17:09:00,52.115,28.003,-1500.5,30.25,2.6
video_1.mp4,2016-12-19 17:09:30,52.118,28.005,null,null,null
video_1.mp4,2016-12-19 17:10:00,52.122,28.011,-1505.5,25.0,5.5

Note that the existing metadata with the same timestamp is updated with new metadata in the lng and lat fields. If metadata is missing for a timestamp, null is inserted.

References

  1. Schoening, T. et al. An acquisition, curation and management workflow for sustainable, terabyte-scale marine image analysis. Sci. Data 5:180181 doi: 10.1038/sdata.2018.181 (2018). doi: 10.1038/sdata.2018.181