GeoPix

GeoLog Journals (行摄志)

A GeoLog (行摄志) is a location-bound photo journal. It stores a set of photos along with a single GPS coordinate representing the place where they were shot. This is the primary workflow in GeoPix.

Creating a Journal

1. Open the GeoLogs tab (books icon at the bottom).
2. Tap the + button in the top-right corner.
3. A location selection screen appears. Search for a place using the search bar, or tap directly on the map to drop a pin.
4. Confirm the location. The journal is created with reverse-geocoded name.

Adding Photos

Inside a journal, tap the Add Photos button at the bottom. Pick photos from your library — multiple selections are supported. Photos are stored locally in the journal until you export them.

Processing (Batch GeoTag)

Tap Process All to write the journal's GPS coordinates to every photo's EXIF. If any photo already has GPS data, a confirmation dialog appears letting you choose to keep the existing tag or overwrite it.

Managing Journals

• Rename: Long-press a journal in the list, or use the "⋯" menu inside the journal detail.
• Delete: Swipe left on a journal in the list and tap the red Delete button.
• Remove a photo: Long-press a photo thumbnail inside the journal and choose Remove.

Map & Location Selection

Tap to Pin

Tap anywhere on the map to place a pin. GeoPix immediately reverse-geocodes the coordinate — usually within a second — and fills in a human-readable name (e.g. "Shinjuku, Tokyo, Japan"). The coordinates themselves are preserved as a fallback if geocoding fails.

Search

Use the search bar at the top of the map screen to search for any address, landmark, or city worldwide. Results from Apple Maps are shown in a list; tapping a result moves the map and places the pin.

Location Name

The location name is stored in the journal title and also embedded in the EXIF ImageDescription field when you export. You can edit it freely before confirming.

GPX Track Import

GPX (GPS Exchange Format) is an open XML format supported by Garmin, Wahoo, Strava, AllTrails, Maps.me, and many other apps and devices.

How to Import

1. Export a .gpx file from your GPS device or app and save it to the iOS Files app (iCloud Drive, On My iPhone, etc.).
2. Inside a journal, tap Import GPX Track. You can also choose a previously recorded track from the app.
3. Pick the .gpx file in the system file picker. GeoPix parses all trackpoints in the background.
4. Use the time offset slider (±12h) to calibrate camera clock drift. Preview matched photos on the map in real time.
5. Confirm to apply. Each photo receives its own precise GPS coordinate via interpolation between the two nearest track points.

Multiple GPX Tracks

A journal can hold multiple GPX tracks. When processing photos, GeoPix evaluates all tracks and their time offsets, automatically picking the best match for each photo.

Tips

• Make sure your camera's clock is set correctly, or use the time offset slider to adjust the difference.
• GPX files with many thousands of points are supported — parsing is done on a background thread.
• A photo whose timestamp falls outside the GPX track window (beyond the tolerance) will not receive automatic coordinates.

GPS Track Recording

GeoPix can turn your iPhone into a GPS track logger. Record your route in real-time while shooting with your camera, then use the recorded track to auto-match photos.

How to Record

1. Open the Track tab at the bottom of the app.
2. Tap the big Start button to begin recording. The app uses kCLLocationAccuracyBestForNavigation with fitness activity type for optimal GPS precision.
3. Walk, drive, or hike while shooting photos. Live stats show elapsed time, distance, and recorded point count.
4. Tap Stop when done. The track is saved as a standard GPX 1.1 file.

Key Features

• Background recording — keeps logging even when the app is in the background or the screen is locked.
• Kalman-filtered smoothing — noisy GPS readings are smoothed for cleaner tracks.
• Precise location detection — warns you if full accuracy (Precise Location) is not enabled, with a direct link to Settings.
• Track history — all recorded tracks are saved with metadata (name, distance, duration) and can be renamed or deleted.
• Direct integration — recorded tracks appear as an import source in the GPX matching wizard.

3D Track Flyover

When your journal has GPX tracks and photos with coordinates, a 3D flyover button appears. This launches an immersive full-screen animation that flies along the track on satellite imagery, revealing your photos at each location as the camera passes.

How It Works

• The entire playback is pre-computed before starting — the track is resampled at uniform distance intervals with smoothed heading.
• Playback duration is proportional to the real track duration (÷20), e.g. a 60-minute track becomes ~3 minutes of animation.
• Photos appear as frosted-glass vertical cards standing on the map at their GPS coordinates when the camera reaches their timestamp.
• Tap any photo card for a full-screen detail view with EXIF info (camera, lens, shooting parameters, coordinates).

Playback Controls

• Play / Pause — preserves position and visible photos.
• Rewind / Forward — jump along the timeline; photo visibility syncs automatically.
• Speed selector — 0.2×–2.0× speed adjustment, responds instantly mid-playback.
• Map style toggle — switch between satellite imagery and standard map.

Cinematic Video Export

Turn your 3D flyover into a shareable 4K or 1080p cinematic video, complete with map rendering, photo animations, elevation profile, and a tactical HUD overlay — all rendered entirely on your device.

How to Export

1. Open a journal with GPX tracks and geotagged photos, then tap the Video Export button (film icon).
2. Choose your settings: map style, resolution (4K / 1080p), frame rate (30 / 24 fps), camera mode (2D / 3D), playback speed (0.2×–4×), and optional drone-drift effect.
3. Tap Start Export. GeoPix downloads map tiles for the track region, then renders each frame off-screen using GPU-accelerated Metal compositing.
4. When rendering is complete, save the video to your Photos library or share it directly via the system share sheet.

Map Styles

GeoPix offers 10 map styles for video export — 5 premium MapTiler styles (Streets, Outdoor, Satellite, Topo, Winter) and 5 free OpenFreeMap styles (Liberty, Bright, Positron, Dark, Fiord). A daily device quota applies to premium styles; free styles have no limits.

Export Settings

• Resolution — 4K (3840×2160) for maximum quality, or 1080p (1920×1080) for faster rendering and smaller file size.
• Frame rate — 30 fps for smooth motion, or 24 fps for a cinematic film look.
• Camera mode — 3D pitched with heading rotation for an immersive drone-like view, or 2D top-down for a clean map overview.
• Playback speed — 0.2× to 4× adjusts how fast the camera flies along the track.
• Drone drift — Subtle multi-frequency camera shake that mimics real aerial footage. Toggle on or off.

Export & EXIF Writing

Save as New Copy vs. Overwrite

In Settings → Export Options you control the default behaviour of the "Process All" button:

• Save as New Copy (ON): A brand-new photo is added to your library with the GPS tag. The original is untouched.
• Save as New Copy (OFF, default): GPS data is written directly to the original photo in-place.

Regardless of the default, you can long-press any photo thumbnail in a journal and choose "Export as New Copy" or "Overwrite Original" for that individual photo.

EXIF Fields Written

• GPSLatitude / GPSLongitude — Degrees, minutes, seconds with reference (N/S, E/W).
• GPSAltitude — Altitude in metres when available.
• GPSLatitudeRef / GPSLongitudeRef — Compass reference.
• GPSAltitudeRef — Above/below sea level reference.

Settings