STH-DCAM USER’S MANUAL 2001 VIDERE DESIGN
STH-DCAM Stereo Head
User’s Manual
Updated – Rev 2
2001 Videre Design
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STH-DCAM USER’S MANUAL 2001 VIDERE DESIGN
9 Technical Specifications ..................................................................... 15
Table of Contents
1
Introduction ...........................................................................................3
2 Quick Start.............................................................................................4
3 Hardware Overview...............................................................................5
3.1 Hardware Schematic......................................................................5
3.2 Color and Monochrome.................................................................5
3.3 Frame Rates ...................................................................................5
4 Lenses ....................................................................................................7
4.1 Changing Lenses............................................................................7
4.2 Cleaning the Imagers .....................................................................7
4.3 Imager Size....................................................................................7
4.4 F Number.......................................................................................7
4.5 Focal Length..................................................................................7
4.6 Range Resolution...........................................................................8
4.7 Field of View.................................................................................8
5 1394 Interface........................................................................................9
5.1 1394 Cable.....................................................................................9
5.2 1394 Host Interface .......................................................................9
9.1 Geometry .................................................................................... 15
9.2 Interface ...................................................................................... 15
9.3 Imagers........................................................................................ 15
9.4 Frame formats and rates.............................................................. 15
9.5 Physical....................................................................................... 15
10 Technical Support ........................................................................... 17
6 User Controls.......................................................................................10
6.1 Color ............................................................................................10
6.2 Video Digitization Parameters.....................................................10
6.3 Subsampling ................................................................................11
6.4 Subwindowing.............................................................................11
6.5 Frame Rates .................................................................................11
7 Installing the 1394 Host Card and Capture Software ..........................12
7.1 1394 Hardware and Drivers.........................................................12
7.2 STH-DCAM Software.................................................................12
7.2.1 MS Windows Installation ....................................................12
7.2.2 Linux Installation.................................................................13
8 Interface Software API ........................................................................14
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STH-DCAM USER’S MANUAL 2001 VIDERE DESIGN
1 Introduction
The STH-DCAM (Dual-DCAM) is a compact, low-power digital stereo
head with an IEEE 1394 digital interface. It consists of two VGA
(640x480), progressive scan CCD imagers and associated IEEE 1394
electronics, mounted in a rigid, milled Delrin frame.
The CCD imagers are Sony HAD ¼” devices, with square pixels and
progressive scan output. They have 648 H by 484 V pixels, and are
colorized using a standard Bayer pattern. These imagers have excellent
dynamic range, sensitivity, anti-blooming, and noise characteristics. They
are fully controllable via the IEEE 1394 interface, in both manual and
automatic modes. The user can set exposure, gain, binning, etc., or have
the stereo head electronics do it automatically.
The STH-DCAM uses standard 12 x 0.5 mm miniature lenses for userchangeable optics. Wide-angle to telephoto options are available,
depending on the application.
There are software drivers for the STH-DCAM for MS Windows
98/2000/XP, and for Linux 2.4.x kernels.
SRI’s Small Vision System (SVS) software has an interface to the STHDCAM. You can simply and automatically calibrate the stereo head,
perform stereo correlation, and view the results as a 3D set. The SVS
software includes all of the capture software described in this document.
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STH-DCAM USER’S MANUAL 2001 VIDERE DESIGN
2 Quick Start
The STH-DCAM comes assembled, with 3.6 mm lenses as standard.
To set up and test the STH-DCAM, you will need the following:
1. Host computer with a 1394 PCI or PCMCIA card, OHCI
compliant.
2. 1394 6-pin cable.
3. Capture software or Small Vision System installed on the host
computer.
Install the 1394 host card, if necessary, according to the directions in
Section 7.1. Install the video capture software (included with the STHDCAM) or Small Vision System software (see Section 7.2). This is the
not-so-quick part of the Quick Start.
The STH-DCAM has a single IEEE 1394 port, for plugging in an IEEE
1394 cable. Plug one end of a 6 pin – 6 pin IEEE 1394 cable into the port,
and the other end into any port of the host card. Note: for PCMCIA cards,
and laptops with a 4-pin Sony iLink port, an external power supply should
be plugged into the STH-DCAM to supply power to the stereo head, using
the 2.1 mm power jack. Standard IEEE 1394 PCI cards supply enough
power, and the power adapter is not necessary.
Start the video capture program, smallvcap(.exe), on the host
computer. You should see a screen as in Figure 2-1. The message window
should indicate that the STH-DCAM interface is present. If not, go back to
software installation (Section 7.2), and follow the instructions for
configuring the correct capture library.
Pull down the Input chooser, and select the Video option. If everything
has been set up, the driver software will recognize and configure the stereo
head after a few seconds, and a success message will appear in the info text
window. If not, the Input chooser will go back to None, and an error
message will appear in the info window. Please see Section 7 for
troubleshooting.
To view stereo video, press the Continuous button. Left and right
images should appear in the application windows. If the message “Image
timed out” appears, then there is a problem with the IEEE 1394 drivers;
please see Section 7. After a few seconds, the images, which are initially
dark, should lighten as the auto exposure mode adjusts to ambient lighting
(Section 6.2). Images can be saved using the File menu.
A more complete description of the video capture program is in Section 6.
The SVS programs are described in the documentation that comes with that
software. It is helpful to review Section 6 in conjunction with the SVS
documentation.
Figure 2-1 Video capture program window.
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STH-DCAM USER’S MANUAL 2001 VIDERE DESIGN
3.1 Hardware Schematic
3 Hardware Overview
Figure 3-1 shows the hardware configuration of the STH-DCAM.
The imager module has a milled Delrin frame that rigidly holds two Sony
HAD CCD color imagers, separated by a fixed distance of 9 cm. Lens
mounts are attached to the frame, and standard miniature lenses are screwed
into these holders. There is an IR curoff filter, with a knee at approximately
700 nm, permanently mounted inside the lens holder. See Section 4 for
appropriate lens characteristics.
There is a IEEE 1394 port on the left side of the device. The cable carries
the data and signals for both imagers. Internally, the imagers are
synchronized so that they are exposed at the same time, a requirement for
stereo processing whenever there is any motion (including camera motion).
Typically, the cable is plugged into the host computer IEEE 1394 card.
Power for the STH-DCAM is supplied from the card, or through a separate
power supply that plugs into the power supply port of the device (7-40
VDC).
There are no user-settable switches on the STH-DCAM.
1394 cables
Right
miniature
lens
Figure 3-1. Physical layout of the STH-DCAM stereo head.
Left
miniature
lens
Figure 3-2 shows the design of the internal hardware of the STH-DCAM.
In the stereo imager module, two Sony CCD imagers, each of size 648x486
pixels, digitize incoming light into a digital stream. A full frame is captured
at once, and then read out line by line. The imagers operate in progressive
mode only, that is, each line is output in succession from the full frame.
The imagers are synchronized to a common clock, so that the corresponding
pixels from each imager are output at the same time. Each imager sends out
its own video stream, on a separate IEEE 1394 cable. There are two such
cables coming out of the STH-DCAM module. Each video stream has a
maximum rate of 200 Mbps; the whole IEEE 1394 bus runs at 400 Mbps.
Each imager is supplied with power from its cable. In order to synchronize
correctly, power must be applied to the imagers at the same time.
Typically, the two cables are connected to a small 3-port IEEE 1394 hub,
which is then connected to the host IEEE 1394 port.
3.2 Color and Monochrome
The Sony CCDs are color imagers, with a standard Bayer color pattern.
Processing in the STH-DCAM can produce either a color or monochrome
output from the imagers. Monochrome output is 1 byte/pixel, and color
outputs are either 2 or 3 bytes/pixel, depending on the format. If color isn’t
necessary, monochrome output should be selected, to save on movement of
data.
3.3 Frame Rates
The IEEE 1394 interface supports a maximum rate of 200 Mbps on each
imager. The maximum frame rates depend on whether monochrome or
color output is used. Frame rates up to 30 Hz at 640x480 are supported.
See Table 3-1 below for a complete list of frame rates.
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STH-DCAM USER’S MANUAL 2001 VIDERE DESIGN
ger
STH-DCAM
Digital Stereo
Head
Figure 3-2 Schematic of the STH-DCAM electronics.
1394
imaging
commands
1394
commands
Left
Imager
1394
Interface
Electronics
1394 Digital
Cable
Sync
signals
8-bit pixels
12 MHz per
ima
Digital
Video
Stream
Right
Imager
1394
Interface
Electronics
Frame Size Frame rate,
monochrome
640x480
30 Hz 30 Hz
Frame rate,
color
15 Hz 15 Hz
7.5 Hz 7.5 Hz
320x240
30 Hz 30 Hz
15 Hz 15 Hz
7.5 Hz 7.5 Hz
Table 3-1 Supported frame rates for the STH-
DCAM, 400 Mbps IEEE 1394 bus.
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