mapillary_download/writer.py
2023-09-12 14:56:14 +02:00

197 lines
6.6 KiB
Python

#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
img = pyexiv2.ImageData(picture)
updated_exif = {}
updated_xmp = {}
if metadata.capture_time:
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 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 metadata.picture_type is not None:
updated_xmp["Xmp.GPano.ProjectionType"] = metadata.picture_type.value
if updated_exif:
img.modify_exif(updated_exif)
if updated_xmp:
img.modify_xmp(updated_xmp)
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_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 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}"