Using Command-Line Tools - Desktop GIS: Mapping the Planet with Open Source Tools - page 179

EXIF_Make=NIKON
EXIF_Model=E4300
EXIF_XResolution=(300)
EXIF_YResolution=(300)
EXIF_DateTime=2007:02:17 07:29:59
...
Corner Coordinates:
Upper Left ( 0.0, 0.0)
Lower Left ( 0.0, 960.0)
Upper Right ( 1280.0, 0.0)
Lower Right ( 1280.0, 960.0)
Center ( 640.0, 480.0)
Band 1 Block=1280x1 Type=Byte, ColorInterp=Red
Computed Min/Max=0.000,255.000
Band 2 Block=1280x1 Type=Byte, ColorInterp=Green
Computed Min/Max=1.000,255.000
Band 3 Block=1280x1 Type=Byte, ColorInterp=Blue
Computed Min/Max=0.000,255.000
There was a lot more metadata in the output, forty-six lines in total.
Basically, every EXIF field a camera stores was dumped. The point is,
gdalinfo can provide detailed information for the formats it supports—
and, yes, just in case you were wondering, you can georeference a
JPEG. You won't see any coordinate system information for the digital
photo; however, if there was a world file associated with it, the informa-
tion would be included in the output.
Using gdalinfo is a quick and efficient way to get information on your
rasters, without having to open them in your GIS application. For com-
plete information on all the options, see the GDAL documentation. 2
Converting Data
The GDAL and OGR utilities allow you to convert data between formats,
optionally changing some of the characteristics in the process. In this
section, we'll look at options and techniques for data conversion, both
raster and vector.
Vector Conversion
First off, let's think about why you might want to convert from one
vector format to another:
• You have data in a format that isn't usable in your desktop GIS
application.
• You need to provide data (to someone or to another application) in
a different format than what you are using.