PHOTO & GPS - [Photo GPS Extractor]
A JPEG file is a computer file that keeps a photo or an image. Most digital cameras write their information to a JPEG file. Besides the image information, these files can contain extra information about the picture. This information is called the Exif data (Exchangeable image file format).
This Exif data can contain information's like: the shutter time, the exposure compensation, diaphragms values, flash settings, the time of the picture, ... This Exif is useful if a photo is bad, and you want to find out what went wrong
Now GPS (Global Positioning System) is becoming more and more accessible to everyone, it is possible to store even your coordinates into a photo. I think there are no cameras yet with a build-in GPS receiver, but some manufacturers already designed GPS receivers that you can connect to your digital camera. At the time you take a picture, your coordinates are automatically stored into the Exif.
You do not have to worry if you do not own a camera with a GPS connection. Sony, for example, designed the GPS-CS1. This device is not connected to your camera. In fact, it just acts as a logging device: at certain time intervals, it stores your location into an internal memory. Afterwards you can download this memory from the device, and synchronize this GPS data with your pictures. A special software tool does this.
This is the procedure: the software tool determines the precise time a picture was taken (This time is stored in the Exif). When it knows the time, it will search your GPS data and calculate the corresponding location on earth. This GPS data is written back to the Exif. Therefore after the synchronization, the locations are also available in the Exif.
There are also other solutions to put the GPS Data into the Exif of images. I just use my portable GPS navigation device, and record my photographic walks. With my GPS, I can export this GPS-log to the computer (This is a file with a .GPX format). Afterwards I synchronize this GPS .GPX file with the aid of software called GRAZER. Grazer calculates the coordinates for each photo, and puts them into the Exif. One bad point about GRAZER is that I do not consider it very accurate. I am currently working on something better and more accurate.
By the way: this whole process calls geotagging. If you are interested in this subject, you can search this word in Google: you will find millions of search results to learn more.
It is very nice that your GPS coordinates are in the Exif of your Images, but what is the further use?
I have made a program called "Photo GPS Extractor". With this program I can right-click on Jpeg images, and choose for the Option "Photo GPS Extractor". Then my program pops up, and shows the following screen:
Photo GPS Extractor shows
a map with a marker on the location where the selected picture was taken.
You can use functions like ZOOM-IN and ZOOM-OUT, PANNING (moving the map by
dragging it).
Of course, you can also start Photo GPS Extractor in the
normal way, and use the command "File/Open Image". The file will be opened,
and the Exif is searched for any GPS coordinates. If the GPS coordinates
(or the Exif it selves) are not available, a warning dialog-box wills pop-up.
Photo GPS Extractor offers some extra options, like the
default Map-type you want to see. You can choose between MAP, SATELLITE and
HYBRID.
- MAP: This card only shows the roads. (This card
starts very quickly.
- SATELLITE: This is a card that shows real photos, taken from
a satellite. You can easily recognize houses and even cars. This card is a
little bit slower to load, and there is no satellite-image available for all
places on earth.
- HYBRID: This is a combination of the MAP and the SATELLITE.
Actually, this program is just a Web Browser application. The maps are provided by Google-Maps: a free service that offers Maps for websites. My software reads the Exif from the selected picture, retrieves the GPS coordinates and afterwards it points the internal web browser to a page on this website. Therefore Photo GPS Extractor does not work on computers without Internet connection.
You can download the program by clicking the link above. You need to unpack the ZIP, and execute the SETUP.EXE file.