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Diffstat (limited to 'bsie/extractor/image/photometrics.py')
| -rw-r--r-- | bsie/extractor/image/photometrics.py | 211 |
1 files changed, 211 insertions, 0 deletions
diff --git a/bsie/extractor/image/photometrics.py b/bsie/extractor/image/photometrics.py new file mode 100644 index 0000000..42eb3c8 --- /dev/null +++ b/bsie/extractor/image/photometrics.py @@ -0,0 +1,211 @@ + +# standard imports +from fractions import Fraction +import typing + +# bsie imports +from bsie.utils import bsfs, node, ns + +# inner-module imports +from .. import base + +# exports +__all__: typing.Sequence[str] = ( + 'Exif', + ) + + +## code ## + +def _gps_to_dec(coords: typing.Tuple[float, float, float]) -> float: + """Convert GPS coordinates from exif to float.""" + # unpack args + deg, min, sec = coords # pylint: disable=redefined-builtin # min + # convert to float + deg = float(Fraction(deg)) + min = float(Fraction(min)) + sec = float(Fraction(sec)) + + if float(sec) > 0: + # format is deg+min+sec + return (float(deg) * 3600 + float(min) * 60 + float(sec)) / 3600 + # format is deg+min + return float(deg) + float(min) / 60 + + +class Exif(base.Extractor): + """Extract information from EXIF/IPTC tags of an image file.""" + + CONTENT_READER = 'bsie.reader.exif.Exif' + + def __init__(self): + super().__init__(bsfs.schema.from_string(base.SCHEMA_PREAMBLE + ''' + #bse:t_capture rdfs:subClassOf bsfs:Predicate ; + # rdfs:domain bsn:Entity ; + # rdfs:range xsd:float ; + # bsfs:unique "true"^^xsd:boolean . + bse:exposure rdfs:subClassOf bsfs:Predicate ; + rdfs:domain bsn:Entity ; + rdfs:range xsd:float ; + bsfs:unique "true"^^xsd:boolean . + bse:aperture rdfs:subClassOf bsfs:Predicate ; + rdfs:domain bsn:Entity ; + rdfs:range xsd:float ; + bsfs:unique "true"^^xsd:boolean . + bse:iso rdfs:subClassOf bsfs:Predicate ; + rdfs:domain bsn:Entity ; + rdfs:range xsd:integer ; + bsfs:unique "true"^^xsd:boolean . + bse:focal_length rdfs:subClassOf bsfs:Predicate ; + rdfs:domain bsn:Entity ; + rdfs:range xsd:float ; + bsfs:unique "true"^^xsd:boolean . + bse:width rdfs:subClassOf bsfs:Predicate ; + rdfs:domain bsn:Entity ; + rdfs:range xsd:integer ; + bsfs:unique "true"^^xsd:boolean . + bse:height rdfs:subClassOf bsfs:Predicate ; + rdfs:domain bsn:Entity ; + rdfs:range xsd:integer ; + bsfs:unique "true"^^xsd:boolean . + bse:orientation rdfs:subClassOf bsfs:Predicate ; + rdfs:domain bsn:Entity ; + rdfs:range xsd:integer ; + bsfs:unique "true"^^xsd:boolean . + bse:orientation_label rdfs:subClassOf bsfs:Predicate ; + rdfs:domain bsn:Entity ; + rdfs:range xsd:string ; + bsfs:unique "true"^^xsd:boolean . + bse:altitude rdfs:subClassOf bsfs:Predicate ; + rdfs:domain bsn:Entity ; + rdfs:range xsd:float ; + bsfs:unique "true"^^xsd:boolean . + bse:latitude rdfs:subClassOf bsfs:Predicate ; + rdfs:domain bsn:Entity ; + rdfs:range xsd:float ; + bsfs:unique "true"^^xsd:boolean . + bse:longitude rdfs:subClassOf bsfs:Predicate ; + rdfs:domain bsn:Entity ; + rdfs:range xsd:float ; + bsfs:unique "true"^^xsd:boolean . + ''')) + # initialize mapping from predicate to callback + self._callmap = { + #self.schema.predicate(ns.bse.t_capture): self._date, + self.schema.predicate(ns.bse.exposure): self._exposure, + self.schema.predicate(ns.bse.aperture): self._aperture, + self.schema.predicate(ns.bse.iso): self._iso, + self.schema.predicate(ns.bse.focal_length): self._focal_length, + self.schema.predicate(ns.bse.width): self._width, + self.schema.predicate(ns.bse.height): self._height, + self.schema.predicate(ns.bse.orientation): self._orientation, + self.schema.predicate(ns.bse.orientation_label): self._orientation_label, + self.schema.predicate(ns.bse.altitude): self._altitude, + self.schema.predicate(ns.bse.latitude): self._latitude, + self.schema.predicate(ns.bse.longitude): self._longitude, + } + + def extract( + self, + subject: node.Node, + content: dict, + principals: typing.Iterable[bsfs.schema.Predicate], + ) -> typing.Iterator[typing.Tuple[node.Node, bsfs.schema.Predicate, typing.Any]]: + for pred in principals: + # find callback + clbk = self._callmap.get(pred) + if clbk is None: + continue + # get value + value = clbk(content) + if value is None: + continue + # produce triple + yield subject, pred, value + + #def _date(self, content: dict): # FIXME: Return type annotation + # date_keys = ( + # 'Exif.Photo.DateTimeOriginal', + # 'Exif.Photo.DateTimeDigitized', + # 'Exif.Image.DateTime', + # ) + # for key in date_keys: + # if key in content: + # dt = content[key].value + # if dt.tzinfo is None: + # dt = dt.replace(tzinfo=ttime.NoTimeZone) + # return dt + # return None + + + ## photometrics + + def _exposure(self, content: dict) -> typing.Optional[float]: + if 'Exif.Photo.ExposureTime' in content: + return 1.0 / float(Fraction(content['Exif.Photo.ExposureTime'])) + return None + + def _aperture(self, content: dict) -> typing.Optional[float]: + if 'Exif.Photo.FNumber' in content: + return float(Fraction(content['Exif.Photo.FNumber'])) + return None + + def _iso(self, content: dict) -> typing.Optional[int]: + if 'Exif.Photo.ISOSpeedRatings' in content: + return int(content['Exif.Photo.ISOSpeedRatings']) + return None + + def _focal_length(self, content: dict) -> typing.Optional[float]: + if 'Exif.Photo.FocalLength' in content: + return float(Fraction(content['Exif.Photo.FocalLength'])) + return None + + + ## image dimensions + + def _width(self, content: dict) -> typing.Optional[int]: + # FIXME: consider orientation! + if 'Exif.Photo.PixelXDimension' in content: + return int(content['Exif.Photo.PixelXDimension']) + return None + + def _height(self, content: dict) -> typing.Optional[int]: + # FIXME: consider orientation! + if 'Exif.Photo.PixelYDimension' in content: + return int(content['Exif.Photo.PixelYDimension']) + return None + + def _orientation(self, content: dict) -> typing.Optional[int]: + if 'Exif.Image.Orientation' in content: + return int(content['Exif.Image.Orientation']) + return None + + def _orientation_label(self, content: dict) -> typing.Optional[str]: + width = self._width(content) + height = self._height(content) + ori = self._orientation(content) + if width is not None and height is not None and ori is not None: + if ori <= 4: + return 'landscape' if width >= height else 'portrait' + return 'portrait' if width >= height else 'landscape' + return None + + + ## location + + def _altitude(self, content: dict) -> typing.Optional[float]: + if 'Exif.GPSInfo.GPSAltitude' in content: + return float(Fraction(content['Exif.GPSInfo.GPSAltitude'])) + return None + + def _latitude(self, content: dict) -> typing.Optional[float]: + if 'Exif.GPSInfo.GPSLatitude' in content: + return _gps_to_dec(content['Exif.GPSInfo.GPSLatitude'].split()) + return None + + def _longitude(self, content: dict) -> typing.Optional[float]: + if 'Exif.GPSInfo.GPSLongitude' in content: + return _gps_to_dec(content['Exif.GPSInfo.GPSLongitude'].split()) + return None + +## EOF ## |