Detect MIME type for Base64Map encoded binary data
MIME type hint, i.e. 'application/json', 'text/plain' etc.
mime type as text
Base64Map vecrtorization: MIME types are extracted, and the maps are converted into PickListMaps and then vectorized using the TextMapPivotVectorizer.
number of values to keep for each key
min times a value must occur to be retained in pivot
clean text before pivoting
clean map keys before pivoting
keys to whitelist
keys to blacklist
optional hint for MIME type detector
option to keep track of values that were missing
other features of the same type
an OPVector feature