Videre Design STH-MD1/-C, STH-MD1 User Manual
STH-MD1 USER’S MANUAL ?2001 VIDERE DESIGN
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STH-MD1/-C Stereo Head
User’s Manual
?2001 Videre Design
STH-MD1 USER’S MANUAL ?2001 VIDERE DESIGN
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Table of Contents
1 Introduction.......................................................................................3
2 Quick Start........................................................................................4
3 Hardware Overview........................................................................... 6
3.1 Hardware Schematic..................................................................6
3.2 Frame Rates...............................................................................6
4 Lenses...............................................................................................8
4.1 Changing Lenses ....................................................................... 8
4.2 Cleaning the Imagers................................................................. 8
4.3 Imager Size ...............................................................................8
4.4 F Number ..................................................................................8
4.5 Focal Length..............................................................................8
4.6 Range Resolution....................................................................... 9
4.7 Field of View.............................................................................9
5 1394 Interface .................................................................................10
5.1 1394 Cable ..............................................................................10
5.2 1394 Host Interface.................................................................. 10
6 User Controls .................................................................................. 11
6.1 Color ....................................................................................... 11
6.2 Gamma Correction ..................................................................11
6.3 Video Digitization Parameters................................................. 12
6.4 Subsampling............................................................................12
6.5 Subwindowing.........................................................................13
6.6 Electronic Pan and Tilt............................................................13
6.7 Electronic Vergence.................................................................13
6.8 Frame Rates............................................................................. 14
7 Installing the 1394 Host Card and Capture Software........................15
7.1 1394 Hardware and Drivers..................................................... 15
7.1.1 MS Windows Hardware Installation.................................15
7.1.2 Linux Hardware and Driver Installation...........................15
7.2 STH-MD1 Software .................................................................15
8 Interface Software API.....................................................................17
9 Mounting Diagrams.........................................................................18
9.1 Bottom Mounting Diagram for the STH-MD1/-C.....................18
9.2 Bottom Mounting Diagram for the STH-MD1/-C-Wide (Rev B)18
10 Technical Specifications...............................................................19
10.1 Geometry .................................................................................19
10.2 Interface...................................................................................19
10.3 Imagers....................................................................................19
10.4 Full-frame rates........................................................................19
10.5 Physical....................................................................................20
11 Technical Support........................................................................21
STH-MD1 USER’S MANUAL ?2001 VIDERE DESIGN
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1 Introduction
The STH-MD1 is a compact, low-power digital stereo head with an IEEE
1394 digital interface. It consists of two 1.3 megapixel, progressive scan
CMOS imagers mounted in a rigid body, and a 1394 peripheral interface
module, joined in an integral unit.
The CMOS imagers are from PixelCam (now a part of Zoran Corporation).
They have 1288 H by 1032 V pixels, and come in either monochrome
(STH-MD1) or colorized (STH-MD1-C) versions. These imagers have
excellent dynamic range, sensitivity, anti-blooming, and noise
characteristics. They are fully controllable via the 1394 interface: the user
can set exposure, gain, subwindow, decimation, etc. They can be used
interchangeably with the same interface module.
The STH-MD1/-C uses standard C-mount lenses for user-changeable
optics. Wide-angle to telephoto options are available, depending on the
application.
The wide baseline version of the STH-MD1/-C has exactly the same
characteristics as the STH-MD1/-C, with the exception of range resolution
and mounting diagrams.
There are software drivers for the STH-MD1/-C 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 STHMD1/-C. 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.
STH-MD1 USER’S MANUAL ?2001 VIDERE DESIGN
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2 Quick Start
The STH-MD1/-C comes assembled, the interface module mounted to the
imager module. The module comes without mounted lenses.
To set up and test the STH-MD1/-C, you will need the following:
1. Pair of C-mount lenses, for 2/3” or larger imager.
2. Host computer with a 1394 PCI or PCMCIA card, OHCI
compliant.
3. 1394 6-pin cable.
4. 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 STHMD1/-C) or Small Vision System software (see Section 7.2). This is the
not-so-quick part of the Quick Start.
Screw the lenses into the mounting holes on the stereo head. Be careful
not to force them initially, as you can cross-thread the lens mount. Snug
them down, but do not tighten excessively.
Plug one end of the 1394 6-pin video cable into either 1394 jack on the
STH-MD1/-C, and the other into a 1394 port on the host PC. Note: for
PCMCIA cards, and laptops with a 4-pin Sony iLink port, an external
power supply and adapter are necessary to convert to a 6-pin (signal +
power) 1394 plug. Most PCMCIA cards come with this adapter.
Start the video capture program, smallv(.exe) or
smallvcap(.exe), on the host computer. You should see a screen as
in Figure 2-1. The message window should indicate that the STH-MD1
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. If the images are too light or too dark, you can open the
manual iris of the cameras, or change the exposure and gain settings
(Section 6.3). 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
Figure 2-1 Video capture program window.
STH-MD1 USER’S MANUAL ?2001 VIDERE DESIGN
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that software. It is helpful to review Section 6 in conjunction with the SVS
documentation.
STH-MD1 USER’S MANUAL ?2001 VIDERE DESIGN
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3 Hardware Overview
Figure 3-1 shows the hardware configuration of the STH-MD1/-C.
The imager module has a milled Delrin frame that rigidly holds two
megapixel imagers, separated by a fixed distance of 9 cm. Lens mounts
are an integral part of the frame, and standard C-mount lenses are screwed
into these holders. There is an IR cutoff filter, with a knee at
approximately 700 nm, permanently mounted inside the lens holder. See
Section 4 for appropriate lens characteristics.
The interface module is mounted on the back of the stereo head. Two 1394
ports are placed at the top of the module. Either port can be used as a
connection to the host PC. The two ports allow daisy-chaining of the 1394
cable to other devices. Use only one port to connect the STH-MD1/-C to
the host computer!
A status LED indicates video imager activity. It will flash at half the frame
rate. It should begin flashing as soon as power is supplied to the camera
through the IEEE 1394 cable, since the imagers are always active, even
when images are not being acquired by the host computer. Changing the
video modes (frame size, decimation) will cause the frame rate to change,
and this will be reflected in the LED flash rate.
There are no user-settable switches on the STH-MD1/-C.
3.1 Hardware Schematic
Figure 3-2 shows the design of the internal hardware of the STH-MD1/-C.
In the stereo imager module, two CMOS imagers, each of size 1288 x 1032
pixels, digitize incoming light into a digital stream. The imagers operate
in progressive mode only, that is, each line is output in succession from the
full frame.
The maximum video rate is 12 megapixels per second from each imager.
The imagers are synchronized to a common clock, so that the
corresponding pixels from each imager are output at precisely the same
time. Special interlace electronics convert the individual streams into a
single pixel-interlaced stream at 24 MHz. The interlaced stream contains
one byte from the left imager, then the corresponding byte from the right
imager, then the next byte from the right imager, and so on.
The interlaced video stream is transferred to the 1394 interface module,
which communicates to the host PC over a 1394 digital cable. The module
also accepts commands from the host PC over the cable, and uses these
commands to control imaging modes such as exposure or subwindowing.
The 1394 interface module can communicate at the maximum 1394 data
rate, 400 MBps.
3.2 Frame Rates
The 1394 interface electronics supports a maximum rate of 24 megapixels
per second. At this rate, there is no need for large buffer memories to hold
video data on the stereo device. At maximum frame size, the frame rate is
7.5 frames per second. Subsampling modes support higher frame rates,
from 26 fps at 640 x 480 to 110 fps at 320 x 240 (Section 6.8).
Figure 3-1. Physical layout of the STH-MD1/-C stereo head.
Left
C-mount
lens
1394 ports
Right
C-mount
lens
LED
indicator
STH-MD1 USER’S MANUAL ?2001 VIDERE DESIGN
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Left
Imager
Right
Imager
Interlace
Electronics
Imager
module
1394
Interface
Electronics
1394
module
8-bit pixels
12 MHz per
imager
Interlaced
pixels
24 MHz
1394
Digital
Cable
1394
imaging
commands
Digital
Video
Stream
1394
commands
Figure 3-2 Schematic of the STH-MD1/-C electronics.
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