Initial commit

Signed-off-by: lymkwi <lymkwi@vulpinecitrus.info>

.gitignore

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+env/

README.md

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+# Korrel
+
+A little python script I wrote to add GPS EXIF data to a batch of photographs using a GPX file.
+
+## How to Run
+
+Simply run the following:
+```bash
+python3 -m venv env
+source env/bin/activate # depending on shell, this may change
+pip3 install -r requirements.txt
+./korrel.py <path to GPX> <photo folder>
+```
+
+Photos in the target folder are written on the fly and sought recursively.
+
+## License
+
+I don't care enough about licensing random shitty tools I write: [ACSL](https://anticapitalist.software/).

korrel.py

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+#!/usr/bin/python3
+"""
+Python tool to tag photos along a GPX track.
+"""
+
+import argparse
+from datetime import datetime, timedelta, timezone
+from decimal import Decimal
+from pathlib import Path
+import sys
+
+import gpx
+import exif
+
+
+def engrave_gpx_data(
+    exif_data: exif.Image, photopath: Path, wpt: gpx.waypoint.Waypoint
+):
+    """Engrave the GPS data from a Waypoint into the image"""
+    # GPSVersionID
+    exif_data["gps_version_id"] = 2
+
+    lat = wpt.lat
+    # GPSLatitudeRef
+    exif_data["gps_latitude_ref"] = "N" if lat >= 0 else "S"
+    lat = abs(lat)
+    # GPSLatitude
+    intlat = int(lat)
+    declat = int((lat - intlat) * 60)
+    decdeclat = (lat - intlat - declat / Decimal(60)) * 3600
+    exif_data["gps_latitude"] = (intlat, declat, decdeclat)
+
+    long = wpt.lon
+    # GPSLongitudeRef
+    exif_data["gps_longitude_ref"] = "E" if long >= 0 else "W"
+    # GPSLongitude
+    long = abs(long)
+    intlong = int(long)
+    declong = int((long - intlong) * 60)
+    decdeclong = (long - intlong - declong / Decimal(60)) * 3600
+    exif_data["gps_longitude"] = (intlong, declong, decdeclong)
+
+    ele = wpt.ele
+    if ele is not None:
+        # GPSAltitudeRef
+        exif_data["gps_altitude_ref"] = 0 if ele >= 0 else 1
+        # GPSAltitude
+        exif_data["gps_altitude"] = abs(ele)
+
+    if wpt.hdop:
+        # GPSDOP
+        exif_data["gps_dop"] = wpt.hdop
+
+    utctime = wpt.time.replace(tzinfo = timezone.utc)
+    # GPSTimeStamp
+    exif_data["gps_datestamp"] = utctime.strftime("%Y:%m:%d")
+    # GPSDateStamp
+    exif_data["gps_timestamp"] = (utctime.hour, utctime.minute, utctime.second)
+
+    with photopath.open(mode="wb") as photo:
+        then = utctime.strftime("%Y:%m:%d %H:%M:%S")
+        print(
+            f"[{then}] {photopath.name}: {intlat}°{declat}'{decdeclat:02.6}\"N ({lat}) {intlong}°{declong}'{decdeclong:02.6}\"W ({long})"
+        )
+        photo.write(exif_data.get_file())
+
+
+def run(gpxf: str, photodir: str):
+    """Run the program"""
+    # Get the file, potentially
+    gpxobj = gpx.GPX.from_file(gpxf)
+    # Open the directory
+    photos = Path(photodir)
+    if not photos.exists():
+        print(f'Unable to open photographs folder "{photodir}" !', file=sys.stderr)
+        return
+
+    # Get the time bounds of the GPX segments
+    gpx_time_bounds = compute_gpx_time_bounds(gpxobj)
+
+    time_photo_dict = find_applicable_images(gpx_time_bounds, photos)
+    times_to_find = list(time_photo_dict.keys())
+    times_to_find.sort()
+
+    # Find the earliest point that is okay for all photos
+    last_point = None
+    for track in gpxobj.tracks:
+        for seg in track.segments:
+            for point in seg.points:
+                if last_point is None:
+                    last_point = point
+                    continue
+
+                if len(times_to_find) == 0:
+                    # Job's done
+                    break
+
+                while (
+                    len(times_to_find) > 0
+                    and last_point.time <= times_to_find[0] < point.time
+                ):
+                    # Oh, `last_point` was what we wanted
+                    engrave_gpx_data(*time_photo_dict[times_to_find[0]], last_point)
+                    times_to_find.pop(0)
+                last_point = point
+
+
+def find_applicable_images(
+    gpx_time_bounds: list[tuple[datetime, timedelta]], photos: Path
+) -> dict[datetime, (exif.Image, Path)]:
+    """Find images in the photo path within the given GPX segment time bounds"""
+    result = {}
+    local_tz = datetime.now(timezone.utc).astimezone().tzinfo
+    for root, _, candidates in photos.walk(
+        top_down=True,
+        on_error=lambda x: print(f"Could not open {x}"),
+        follow_symlinks=True,
+    ):
+        for candidate in candidates:
+            with open(root / candidate, mode="rb") as candidate_file:
+                exif_data = exif.Image(candidate_file)
+                if len(exif_data.list_all()) == 0:
+                    continue
+                candidate_time = datetime.strptime(
+                    exif_data.datetime_original, "%Y:%m:%d %H:%M:%S"
+                ).replace(tzinfo=local_tz)
+
+                # Find an applicable time bound
+                for bound_min, bound_dur in gpx_time_bounds:
+                    if bound_min <= candidate_time < bound_min + bound_dur:
+                        result[candidate_time] = (exif_data, Path(root / candidate))
+
+    print(f"Found {len(result)} candidate pictures")
+
+    return result
+
+
+def compute_gpx_time_bounds(gpxobj: gpx.gpx.GPX) -> list[tuple[datetime, timedelta]]:
+    """Compute the time bounds of GPX segments"""
+    return [
+        (seg.points[0].time, seg.duration)
+        for track in gpxobj.tracks
+        for seg in track.segments
+    ]
+
+
+def main():
+    """The main function"""
+    args = parse_arguments()
+    run(args.gpx_file, args.photo_older)
+
+
+def parse_arguments() -> argparse.Namespace:
+    """Parse arguments to the programs"""
+    parser = argparse.ArgumentParser(
+        prog="korrel",
+        description="Correlate and tag images using a GPX track",
+        usage="%(prog)s [-h] <gpx_file> <photo_folder>",
+    )
+    parser.add_argument("gpx_file")
+    parser.add_argument("photo_older")
+
+    return parser.parse_args()
+
+
+if __name__ == "__main__":
+    main()

requirements.txt

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+exif==1.6
+gpx==0.2