iFDO capture fields

The iFDO capture is one section of the complete iFDO file. See its description to learn about its file formats, parts and sections. All fields in this section are optional!

Motivation

Information on how image data was captured can be crucial to understand information extracted from the images. It is thus highly recommended to enrich all iFDOs with capture information. The potential metadata in the iFDO capture fields is expected to grow with time, as additional (marine) imaging domains make use of this concept. Anyhow, below you find a pool of iFDO capture fields which are highly recommended to be added to your iFDO. Only with these fields populated will your dataset shine in a marine data portal! By limiting some of these fields to restricted values only, it is possible to classify and filter image data sets in data portals and to visualize data characteristics. See the iFDO capture icon overview for more details.

File format

All iFDO capture fields shall be stored alongside the core metadata in your iFDO file! It does not take up a specific section of the file, rather the values are intermixed into the image-set-header and image-set-items section!

iFDO capture fields

Field	Type	Description
image-acquisition	string	photo: still images, video: moving images, slide: microscopy images / slide scans
image-quality	string	raw: straight from the sensor, processed: QA/QC’d, product: image data ready for interpretation
image-deployment	string	mapping: planned path execution along 2-3 spatial axes, stationary: fixed spatial position, survey: planned path execution along free path, exploration: unplanned path execution, experiment: observation of manipulated environment, sampling: ex-situ imaging of samples taken by other method
image-navigation	string	satellite: GPS/Galileo etc., beacon: USBL etc., transponder: LBL etc., reconstructed: position estimated from other measures like cable length and course over ground
image-scale-reference	string	3D camera: the imaging system provides scale directly, calibrated camera: image data and additional external data like object distance provide scale together, laser marker: scale information is embedded in the visual data, optical flow: scale is computed from the relative movement of the images and the camera navigation data
image-illumination	string	sunlight: the scene is only illuminated by the sun, artificial light: the scene is only illuminated by artificial light, mixed light: both sunlight and artificial light illuminate the scene
image-pixel-magnitude	string	average size of one pixel of an image
image-marine-zone	string	seafloor: images taken in/on/right above the seafloor, water column: images taken in the free water without the seafloor or the sea surface in sight, sea surface: images taken right below the sea surface, atmosphere: images taken outside of the water, laboratory: images taken ex-situ
image-spectral-resolution	string	grayscale: single channel imagery, rgb: three channel imagery, multi-spectral: 4-10 channel imagery, hyper-spectral: 10+ channel imagery
image-capture-mode	string	whether the time points of image capture were systematic, human-triggered or both
image-fauna-attraction	string	Allowed: none, baited, light
image-area-square-meters	number	The footprint of the entire image in square meters
image-meters-above-ground	number	Distance of the camera to the seafloor in meters
image-acquisition-settings	object	All the information that is recorded by the camera in the EXIF, IPTC etc. As a dict. Includes ISO, aperture, etc.
image-camera-yaw-degrees	number	Camera view yaw angle. Rotation of camera coordinates (x,y,z = top, right, line of sight) with respect to NED coordinates (x,y,z = north,east,down) in accordance with the yaw,pitch,roll rotation order convention: 1. yaw around z, 2. pitch around rotated y, 3. roll around rotated x. Rotation directions according to “right-hand rule”. I.e. for yaw,pitch,roll = 0,0,0 camera is facing downward with top side towards north.
image-camera-pitch-degrees	number	Camera view pitch angle. Rotation of camera coordinates (x,y,z = top, right, line of sight) with respect to NED coordinates (x,y,z = north,east,down) in accordance with the yaw,pitch,roll rotation order convention: 1. yaw around z, 2. pitch around rotated y, 3. roll around rotated x. Rotation directions according to “right-hand rule”. I.e. for yaw,pitch,roll = 0,0,0 camera is facing downward with top side towards north.
image-camera-roll-degrees	number	Camera view roll angle. Rotation of camera coordinates (x,y,z = top, right, line of sight) with respect to NED coordinates (x,y,z = north,east,down) in accordance with the yaw,pitch,roll rotation order convention: 1. yaw around z, 2. pitch around rotated y, 3. roll around rotated x. Rotation directions according to “right-hand rule”. I.e. for yaw,pitch,roll = 0,0,0 camera is facing downward with top side towards north.
image-overlap-fraction	number	The average overlap of two consecutive images i and j as the area images in both of the images (A_i * A_j) divided by the total area images by the two images (A_i + A_j - A_i * A_j): f = A_i * A_j / (A_i + A_j - A_i * A_j) -> 0 if no overlap. 1 if complete overlap
image-datetime-format	string	A date time format string in Python notation to specify a date time format used throughout the iFDO file that differs from the default one ‘%Y-%m-%d %H:%M:%S.%f’. Make sure to reach second-accuracy with your date times!
image-camera-pose	object	Information required to specify camera pose. Details given in properties.
image-camera-housing-viewport	object	Information on the camera pressure housing viewport (the glass). Details given in properties.
image-flatport-parameters	object	Information required to specify the characteristics of a flat port camera housing. Details given in properties.
image-domeport-parameters	object	Information required to specify the characteristics of a dome port camera housing. Details given in properties.
image-camera-calibration-model	object	Information required to specify the camera calibration model. Details given in properties.
image-photometric-calibration	object	Information required to specify the photometric calibration. Details given in properties.
image-objective	string	A general description of the aims and objectives of the study, as they pertain to biology and method scope. This should define the primary and secondary data to be measured and to what precision.
image-target-environment	string	A description, delineation, and definition of the habitat or environment of study, including boundaries of such
image-target-timescale	string	A description, delineation, and definition of the period, interval or temporal environment of the study.
image-spatial-constraints	string	A description / definition of the spatial extent of the study area (inside which the photographs were captured), including boundaries and reasons for constraints (e.g. scientific, practical)
image-temporal-constraints	string	A description / definition of the temporal extent, including boundaries and reasons for constraints (e.g. scientific, practical)
image-time-synchronisation	string	Synchronisation procedure and determined time offsets between camera recording values and UTC
image-item-identification-scheme	string	How the images file names are constructed. Should be like this image-project_image-event_image-sensor_image-datetime.ext
image-curation-protocol	string	A description of the image and metadata curation steps and results
image-visual-constraints	string	An explanation how the images might be degraded (turbidity, blocked view, …)
image-set-min-latitude-degrees	number	The lower bounding box latitude enclosing all images in the set
image-set-max-latitude-degrees	number	The upper bounding box latitude enclosing all images in the set
image-set-min-longitude-degrees	number	The lower bounding box longitude enclosing all images in the set
image-set-max-longitude-degrees	number	The upper bounding box longitude enclosing all images in the set
image-set-related-material	array	Links to other resources that are related to this image set.
image-set-provenance	object	A schema to document the agents, activities and entities that led to an image set entity