Introduction - Open Source Geospatial Tools: Applications in Earth Observation - page 13

Fig. 1.6 otbViewer interface
The application can be launched by typing openev from the command line and
new data can be added to the map canvas by selecting File --> Import , where
it is then possible to navigate to the geospatial dataset that you want to load. The
interface is presented in Fig. 1.5 with a satellite image loaded. The toolbar provides
buttons to apply enhancements to the raster data with a single click. By pressing the
Ctrl key with the left mouse button pressed, you can zoom in at any factor. Pressing
the Ctrl key while dragging the window creates a new zoom window.
OpenEV also provides the capability to perform some basic geospatial analysis
including unsupervised classification using the ISOData Algorithm and to access a
Python shell from within OpenEV. Overall, it is a very fast and efficient application
that can be used to easily visualize geospatial data from the command line. However,
the visualization capabilities is limited to simple geometric features. Unfortunately,
at the time of writing, it is no longer part of the OSGeo Live distribution.
The Orfeo Toolbox includes a viewer, simply named otbViewer .Themain
window allows for the selection of raster image files, which are summarized within
the window including a thumbnail and a brief listing of metadata (see Fig. 1.6 ). By
opening an image, a new window appears that includes a full resolution view of
the image as well as navigation, zoom and histogram views and window detailing
the pixel information (pixel value, geographic coordinates and image row/column