User manual

Small Vision System User Manual 10
2 Getting started with smallv
The smallv program is a standalone application that exercises the SVS library. It is a GUI interface
to the stereo programs, and in addition can load and save stereo image sequences. The smallv program
is a useful tool for initial development of a stereo application, and can also be used to check out and adjust
a stereo camera setup.
The smallv program is in the bin/ directory. It requires shared libraries for the stereo algorithms
(svs), display (fltk), and calibration (various), all of which are in the bin/ directory. Under MS
Windows, these shared libraries (DLLs) must be in the same directory as the smallv program, or in the
system DLL directory. Under UNIX, the LD_LIBRARY_PATH variable must have the path to the
libraries.
Figure 2-1 shows the startup screen of the program. The black windows are for display of image and
stereo data. The display programs in SVS use the FLTK cross-platform window interface, and work best
in 24 bit video display mode. The version of the program is indicated in the text information area, and the
title bar.
smallv will accept stereo images from either a live video source, or a stored file. The easiest way to
get started with the program is to open a stored stereo sequence. From the File menu, choose Open,
and navigate to the data/ directory. The file face320-cal-X.bmp contains a stereo frame at
320x240 resolution. When you open it, it will show in the display windows. In the Function area, pull
down the list box and choose Stereo. Finally, press the Continuous button to compute the stereo
disparity and display it. You should see a green pattern representing stereo disparities in the right window.
Under the Horopter label, click the X offset button a few times to see the effect of changing the
stereo search area; a value of –4 or so should bring the close parts of the face into range. Clicking the 3D
Display button brings up an OpenGL window with a 3D view of the stereo data.
The rest of this section explains the operation of smallv. Since smallv exercises most of the
functionality of the SVS libraries, it should serve as a general introduction to the SVS functions. If you are
interested in using a particular framegrabber and set of cameras with smallv, please see Section 2.1. The
Figure 2-1 Smallv program interface. The two black windows are for display of input images
and stereo results.