MAPC2MAPC Help pages - Geocoding Photographs

Overview How to .... Grids and Datums Map Images Uses

Digital photographs stored as JPG files con contain much more than the image. Data within the JPG will contain the time and date, model of camera, shutter speed etc. The data can also contain the location where the picture was taken on your journey. Some Smartphones and a few cameras will do this automatically if their GPS is enabled but most cameras will not record the location. But maybe you want the location to upload to Google Earth or other applications. From version 538, MAPC2MAPC provides a simple way to do this if you have recorded a track with a GPS that spans the time in which the picture were recorded. You need a map covering the journey, too. This can be an image on your computer or downloded from an online source such as Open Street Map or various WMS servers. The process works because tracks record the time of each track point and digital cameras always record the time of the picture. The track time is always recorded as UTC (which used to be called GMT and is called Zulu by airlines). The camera time will be different because of different time zones around the world, daylight saving time and/or inaccuracies in the camera's clock. So if the difference between the camera time and GPS time can be calculated then each picture's location can be calculated from that of the track point nearest to the adjusted time. So this is the process, in Expert mode. 1. Download Exiftool (choose the Windows executable), remove the(-k) from the name of the program then use Edit>Locate to tell MAPC2MAPC where it is. 2. Open a map and use track manager to load one track (KML or GPX) or download the map from an online source using a track to define the area downloaded. 3. Click Utilities>GEOCode Photographs and open any JPG file in the folder whose pictures are to be GEOCoded.. 4. You will then see a screen with the map and a strip of pictures displayed. You can scroll through the list by clicking the arrow icons. Or click on them to see full size. Drag one picture to its place on the track and you will see lines linking all the other pictures to their location. If these are not correct, drag the picture to a different place or choose another picture. 5. When you are happy click the Apply GEOCode button to update the pictures with the calculated location. You can also copy these locations to the clipboard. It is important to drag a picture whose time can be accurately found from the track. So choose a picture that you paused briefly to take, rather than one taken in the middle of a long lunch!