#source : https://gitlab.com/geovisio/geo-picture-tag-reader/-/blob/main/geopic_tag_reader/writer.py from typing import Optional, Tuple from datetime import datetime, timedelta from dataclasses import dataclass from model import PictureType try: import pyexiv2 # type: ignore except ImportError: raise Exception( """Impossible to write the exif tags without the '[write-exif]' dependency (that will need to install libexiv2). Install this package with `pip install geopic-tag-reader[write-exif]` to use this function""" ) import timezonefinder # type: ignore import pytz tz_finder = timezonefinder.TimezoneFinder() @dataclass class PictureMetadata: capture_time: Optional[datetime] = None longitude: Optional[float] = None latitude: Optional[float] = None altitude: Optional[float] = None picture_type: Optional[PictureType] = None direction: Optional[float] = None orientation: Optional[int] = 1 def writePictureMetadata(picture: bytes, metadata: PictureMetadata) -> bytes: """ Override exif metadata on raw picture and return updated bytes """ if not metadata.capture_time and not metadata.longitude and not metadata.latitude and not metadata.picture_type: return picture if metadata.capture_time: picture = add_gps_datetime(picture, metadata) if metadata.latitude is not None and metadata.longitude is not None: picture = add_lat_lon(picture, metadata) if metadata.picture_type is not None: picture = add_img_projection(picture, metadata) return picture def add_lat_lon(picture: bytes, metadata: PictureMetadata) -> bytes: """ Add latitude and longitude values in GPSLatitude + GPSLAtitudeRef and GPSLongitude + GPSLongitudeRef """ img = pyexiv2.ImageData(picture) updated_exif = {} if metadata.latitude is not None: updated_exif["Exif.GPSInfo.GPSLatitudeRef"] = "N" if metadata.latitude > 0 else "S" updated_exif["Exif.GPSInfo.GPSLatitude"] = _to_exif_dms(metadata.latitude) if metadata.longitude is not None: updated_exif["Exif.GPSInfo.GPSLongitudeRef"] = "E" if metadata.longitude > 0 else "W" updated_exif["Exif.GPSInfo.GPSLongitude"] = _to_exif_dms(metadata.longitude) if updated_exif: img.modify_exif(updated_exif) return img.get_bytes() def add_altitude(picture: bytes, metadata: PictureMetadata, precision: int = 1000) -> bytes: """ Add altitude value in GPSAltitude and GPSAltitudeRef """ altitude = metadata.altitude img = pyexiv2.ImageData(picture) updated_exif = {} if altitude is not None: negative_altitude = 0 if altitude >= 0 else 1 updated_exif['Exif.GPSInfo.GPSAltitude'] = f"{int(abs(altitude * precision))} / {precision}" updated_exif['Exif.GPSInfo.GPSAltitudeRef'] = negative_altitude if updated_exif: img.modify_exif(updated_exif) return img.get_bytes() def add_gps_datetime(picture: bytes, metadata: PictureMetadata) -> bytes: """ Add GPSDateStamp and GPSTimeStamp """ img = pyexiv2.ImageData(picture) updated_exif = {} if metadata.capture_time.utcoffset() is None: metadata.capture_time = localize(metadata, img) # for capture time, override GPSInfo time and DatetimeOriginal updated_exif["Exif.Photo.DateTimeOriginal"] = metadata.capture_time.strftime("%Y:%m:%d %H:%M:%S") offset = metadata.capture_time.utcoffset() if offset is not None: updated_exif["Exif.Photo.OffsetTimeOriginal"] = format_offset(offset) utc_dt = metadata.capture_time.astimezone(tz=pytz.UTC) updated_exif["Exif.GPSInfo.GPSDateStamp"] = utc_dt.strftime("%Y:%m:%d") updated_exif["Exif.GPSInfo.GPSTimeStamp"] = utc_dt.strftime("%H/1 %M/1 %S/1") if updated_exif: img.modify_exif(updated_exif) return img.get_bytes() def add_direction(picture: bytes, metadata: PictureMetadata, ref: str = 'T', precision: int = 1000) -> bytes: """ Add direction value in GPSImgDirection and GPSImgDirectionRef """ direction = metadata.direction img = pyexiv2.ImageData(picture) updated_exif = {} if metadata.direction is not None: updated_exif['Exif.GPSInfo.GPSImgDirection'] = f"{int(abs(direction % 360.0 * precision))} / {precision}" updated_exif['Exif.GPSInfo.GPSImgDirectionRef'] = ref if updated_exif: img.modify_exif(updated_exif) return img.get_bytes() def add_img_projection(picture: bytes, metadata: PictureMetadata) -> bytes: """ Add image projection type (equirectangular for spherical image, ...) in xmp GPano.ProjectionType """ img = pyexiv2.ImageData(picture) updated_xmp = {} if metadata.picture_type is not None: updated_xmp["Xmp.GPano.ProjectionType"] = metadata.picture_type.value updated_xmp["Xmp.GPano.UsePanoramaViewer"] = True if updated_xmp: img.modify_xmp(updated_xmp) return img.get_bytes() def format_offset(offset: timedelta) -> str: """Format offset for OffsetTimeOriginal. Format is like "+02:00" for paris offset >>> format_offset(timedelta(hours=5, minutes=45)) '+05:45' >>> format_offset(timedelta(hours=-3)) '-03:00' """ offset_hour, remainer = divmod(offset.total_seconds(), 3600) return f"{'+' if offset_hour >= 0 else '-'}{int(abs(offset_hour)):02}:{int(remainer/60):02}" def localize(metadata: PictureMetadata, imagedata: pyexiv2.ImageData) -> datetime: """ Localize a datetime in the timezone of the picture If the picture does not contains GPS position, the datetime will not be modified. """ exif = imagedata.read_exif() try: lon = exif["Exif.GPSInfo.GPSLongitude"] lon_ref = exif.get("Exif.GPSInfo.GPSLongitudeRef", "E") lat = exif["Exif.GPSInfo.GPSLatitude"] lat_ref = exif.get("Exif.GPSInfo.GPSLatitudeRef", "N") except KeyError: return metadata.capture_time # canot localize, returning same date lon = _from_dms(lon) * (1 if lon_ref == "E" else -1) lat = _from_dms(lat) * (1 if lat_ref == "N" else -1) tz_name = tz_finder.timezone_at(lng=lon, lat=lat) if not tz_name: return metadata.capture_time # cannot find timezone, returning same date tz = pytz.timezone(tz_name) return tz.localize(metadata.capture_time) def _from_dms(val: str) -> float: """Convert exif lat/lon represented as degre/minute/second into decimal >>> _from_dms("1/1 55/1 123020/13567") 1.9191854417991367 >>> _from_dms("49/1 0/1 1885/76") 49.00688961988304 """ deg_raw, min_raw, sec_raw = val.split(" ") deg_num, deg_dec = deg_raw.split("/") deg = float(deg_num) / float(deg_dec) min_num, min_dec = min_raw.split("/") min = float(min_num) / float(min_dec) sec_num, sec_dec = sec_raw.split("/") sec = float(sec_num) / float(sec_dec) return float(deg) + float(min) / 60 + float(sec) / 3600 def _to_dms(value: float) -> Tuple[int, int, float]: """Return degree/minute/seconds for a decimal >>> _to_dms(38.889469) (38, 53, 22.0884) >>> _to_dms(43.7325) (43, 43, 57.0) >>> _to_dms(-43.7325) (43, 43, 57.0) """ value = abs(value) deg = int(value) min = (value - deg) * 60 sec = (min - int(min)) * 60 return deg, int(min), round(sec, 8) def _to_exif_dms(value: float) -> str: """Return degree/minute/seconds string formated for the exif metadata for a decimal >>> _to_exif_dms(38.889469) '38/1 53/1 55221/2500' """ from fractions import Fraction d, m, s = _to_dms(value) f = Fraction.from_float(s).limit_denominator() # limit fraction precision num_s, denomim_s = f.as_integer_ratio() return f"{d}/1 {m}/1 {num_s}/{denomim_s}"