Describes whether the image was captured transmissively or reflectively.
None
Integer
No default
TWLP_REFLECTIVE(0), TWLP_TRANSMISSIVE(1)
TW_ENUMERATION, TW_ONEVALUE
TW_ONEVALUE
ICAP_EXPOSURETIME, ICAP_FLASHUSED2, ICAP_LAMPSTATE, ICAP_LIGHTSOURCE