Images and movies often have data embedded into their source file which is usually inserted by the device that created the image (e.g. a digital camera). In Asset Bank it is possible to harvest this data and use it to populate an assets attribute values automatically. To do this you need to first set up a mapping between the embedded data field and an attribute in Asset Bank. This is achieved on the Embedded Data Mappings page:
When adding a new data mapping you need to provide the following information:
- Attribute - Select an attribute that you want the embedded data field to map to. You may want to set up a custom attribute for this on the Manage Attributes page.
- Embedded data type - There are a number of different formats for embedded data depending on the file format of the image and the device used to create the image. Each format has a different set of fields, so you will need to know the format of the field you are interested in and specify it here.
- Mapping direction - Select 'Upload' if you want the system to copy an embedded data value into an attribute value when you upload the image. Select 'Download' if you want the system to copy an attribute value into an embedded data field when you download the image.
Note: If you set a download mapping and have the setting download-remote-storage-directly set to true, files which will have the data mapping embedded to them will not be downloaded directly from the remote storage device
- Delimiter - If the attribute contains multiple values (such as a keywords fields) then you can specify a delimiter here.
- Binary data - If the value of the metadata field is a binary value then this checkbox needs to be ticked for the mapping to work.
Setting up more than one mapping with the same target is not recommended, because if more than one value is found for the same target attribute or embedded data field then the last value found will overwrite the previous value(s).
GPS data mappings
You can define some special mappings for mapping GPS embedded data in images to and from Asset Bank attributes. These mappings are found when you select 'Other' as the Embedded data type. The following options are included for Embedded data value:
- GPS Position Signed - in the Upload direction, this mapping reads EXIF or Composite Longitude and Latitude data simultaneously, and maps to the asset attribute value. Usually the attribute should be of type Spatial Area, in which case the data will be mapped to a point value for the attribute. Otherwise (e.g. for text attributes) the value will just be of the format '(latitude,longitude)' with the coordinates in Signed Decimal Degrees format.
- GPS Longitude Signed - this reads EXIF or Composite Longitude data and maps to an asset attribute value in Signed Decimal Degrees format, for example, longitude 11°53'4.34" W is mapped to ‑11.885. Usually an attribute of type Numeric should be chosen, but text attributes would also work.
- GPS Latitude Signed - similarly reads EXIF or Composite Latitude data and maps to an asset attribute value in Signed Decimal Degrees format.
If you have an attribute of type Spatial Area, then you should choose GPS Position Signed as the mapping (GPS Longitude or GPS Latitude mappings are not supported for Spatial Area attributes).
GPS mappings can also be applied in the Download direction. For the GPS Position Signed mapping, this will only work if the attribute is a Spatial Area (so that the longitude and latitude values can be correctly read out from the asset attribute value). For GPS Latitude and GPS Longitude mappings, then the attribute should be a Numeric type.
Applying your mappings
Depending on what mapping direction you have defined then data will be transferred automatically on upload or download. You can also apply your mappings retrospectively by clicking the 'rerun metadata extraction for existing assets'.
In addition, for dropdown attributes you can enter, for each dropdown entry, a corresponding ‘Metadata value’ so that if that value is found embedded in an image when it is uploaded, that dropdown entry will be automatically selected. (To do that, go to Admin > Attributes, then click ‘edit list values’ next to the dropdown attribute, then click ‘edit’ next to the value you want to edit and then enter the corresponding ‘embedded value’ in the mapping field.)
Rerunning Embedded Metadata Extraction
From Attributes > Embedded Data Mappings select rerun metadata extraction for existing assets.
You may select one or more mapping to rerun. Be aware that any attribute involved in a mapping will be overwritten with the value in the embedded metadata so only select those you require.
You may select a single Asset ID to rerun or alternatively you may select a range (the Lower ID is the first in the range and the Upper ID is the last in the range).
Click Run Extraction to begin. This may take some time if there are many assets to process. The page will refresh to update on the progress of extraction.