Load GPX Convert GPX Load XML Apply XML
Load map Photos folder Inspector Export XML

Introduction

Track Converter is inspired from Track Viewer whose purpose was to visualize on a map the places where photos were taken.
The main difficulty was to obtain calibrated maps.
Here the map is provided by Google Maps API for the whole world !

The application builds an overlay made of Markers and Polylines by means of GPS tracks and Time data of the photos (from EXIF metadata).
Each marker has a short legend in HTML format which may contain, of course, links to more data.

Interface updating relies mainly on Cocoa Bindings.

How does it work

The content of the window and the Javascript machinery are in the file GMaps.html.
Google Maps API gives access to GMap object and permits to draw on it by means of overlays which comprises GMarker and GPolyline objects.
Cocoa API provides the WebView object which handles all necesary dialog with Web server to update the map display along user actions.

Usage

Load GPX

Loads a .gpx file to read TrkSeg tags and for each TrkSeg, TrkPnts.
A .pdb file is automaticly converted in gpx by TrackLog Unix command.

Convert GPX

The main purpose of this software : makes a XML content suitable for Google Maps.
No markers are generated in the process, only polylines following TrkSegs.
Because the map rely on (at least) two markers for center itself and choose a suitable zoom factor, two markers are calculated from the min and max of latitude and longitude.

Load XML

An available XML file is loaded (and applied if map is loaded).
Read also KML files from Google Earth and convert Placemarks to Markers.

Apply XML

Reapply the XML content to the map in case some attributes have changed.

Load map

Loads the URL above the button in the Web view. If a XML content is available, it is applied to the map. Automatic centering of the map and zoom level is performed from markers array.

Choose photos folder

If photos contain GPS metadata, it is used to make Markers.
If not, a track is necessary, time from EXIF data is compared with GPS time of TrkPnts.
A Marker is generated for each photo, from the closest (in time) TrkPnt.

Export XML

In the File menu.
Saves the Markers and Polylines with their attributes.

Inspector

The Inspector gives details for Markers and Lines attributes.
It opens (and closes) with the button.
The button gets Latitude and Longitude from the last click in the map view.
The button gives the end of the path to an image file for the marker legend (URL field).

In the bottom part, one can offset the entire overlay (Markers and Lines).
The origin is the selected Marker or last expanded marker (see Preferences), the destination can be obtained by the button.

Preferences

One can choose default line color, width and opacity.

In offset mechanism, the difference calculus can be made with the selected marker in the markers list or with the last expanded marker in the map view.