User manual

Small Vision System User Manual 13
1. Use two framegrabbers, and input one signal on each.
2. Use a single framegrabber capable of inputting 2 monochrome channels, e.g., the Matrox
Meteor RGB or Meteor II / Multichannel.
3. Use a single framegrabber, and a stereo head that interlaces two video signals onto a single
video stream. The STH-V3 from Videre Design (www.videredesign.com) is one such stereo
head.
4. Use a digital stereo head, the MEGA-D (STH-MD1) from Videre Design. This stereo head
outputs a digital signal on the 1394 bus, and any OHCI (Open Host Controller Interface) card
can be used to input the video.
The SVS libraries can work with any size video frame up to 1288 by 1032 pixels. Standard NTSC
cameras capture frames up to 640 by 480, as a set of two fields, each 640 by 240. The camera first
captures a field in 1/60 of a second (the even field), then captures a second field 1/60 of a second later (the
odd field). The framegrabber can put these together to form a single image of 640 by 480 size. However,
the same problem with motion between non-genlocked cameras can occur on a single camera that
combines fields. There is a slight time delay between fields, leading to motion blur in the composed
frame. For this reason, the SVS libraries use fields rather than frames, so the maximum video size for
NTSC signals is 640 by 240.
PAL cameras are also support by the SVS libraries, as long as the framegrabber can input PAL video.
They involve similar considerations, but their maximum field size is 768 by 288.
Larger frame sizes with synchronized cameras are possible by using nonstandard progressive scan
analog cameras, or digital cameras.
2.1.2 Analog Framegrabbers
The SVS libraries include support for a number of popular analog signal framegrabbers; for digital
stereo heads, see the next subsection. The table below lists them according to their operating system.
Under MS Windows, a particular framegrabber is accessed from the SVS libraries by copying the
corresponding DLL and LIB files. Copy the appropriate C++ library (.dll) for your framegrabber to
svsgrab.dll, and the corresponding reference file (.lib) to svsgrab.lib. For example, if you
have installed the Matrox Meteor II board, then copy the following files in the bin\ directory:
Operating
System
Framegrabber Library MSW Installation
File
Matrox Meteor, Meteor RGB, Meteor PPB
bttvcap.so
Any Bt848-based card, e.g.
Intel Smart Video Recorder III
Imagenation PXC2000
bttvcap.so
Linux
None
nullcap.so
Matrox Meteor, Meteor RGB, Meteor PPB
svsmet.dll setup_met.bat
Matrox Meteor II
svsmet2.dll setup_met2.bat
Imagenation PXC200
svspxc.dll setup_pxc.bat
MS Windows
95/98/2000/XP
None
svsnull.dll setup_null.bat
Matrox Meteor, Meteor RGB, Meteor PPB
svsmet.dll setup_met.bat
Meteor II
svsmet2.dll setup_met2.bat
MS Windows
NT 4.0
Imagenation PXC200
svspxc.dll setup_pxc.bat
Table 2-1 Framegrabbers supported by SVS.
svsmet2.dll -> svsgrab.dll
svsmet2.lib -
> svsgrab.lib