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DCSG

 

U

SER

M

ANUAL

   

 

 

 

 

 

    

 

 

 

 

 

                       

©

2007

 

V

IDERE 

D

ESIGN

 

 

3.2  Color and Monochrome 

The imager is either monochrome (DCSG) or color Bayer pattern (DCSG-
C). Output is 1 byte/pixel for either device.  The Bayer pattern is converted 
into color information on the host computer, via routines in the DCAM 
software. 

3.3 Frame 

Rates 

The IEEE 1394 interface on the DCSG supports a maximum rate of 400 
Mbps from the imager.  Frame rates up to 60 Hz at 640x480 are supported.  
See Table 3-1 below for a complete list of frame rates.   

3.4  50 Hz Option 

Indoor lighting, especially from fluorescent fixtures, can oscillate at the 
frequency of the electrical supply.  If the image frame rate does not divide 
evenly into this frequency, there can be moving horizontal bands of 
alternating light and dark moving in the output. 

For countries with 60 Hz power such as the United State, the standard 
frame rates are ideal.  In many other countries, the electrical line frequency 
is 50 Hz.  For these countries, there is a mode to change the frame rates of 
the DCSG to sub-multiples of 50 Hz.  These frame rates are shown in the 
last column of Table 3-1 

3.5 Multiple 

Devices 

Multiple DCSG devices can be attached to the same IEEE 1394 bus.  When 
streaming video at the same frame rate, they are synchronized, so that they 
capture images at the same time. 

Each IEEE 1394 PC Card or PCI Card defines a separate IEEE 1394 bus.  
The two or three ports on the card all belong to the same bus, as does any 
IEEE 1394 hub connected to these ports.  Separate PC Cards and PCI Cards 
cannot be connected to each other. 

The number of devices that can simultaneously send video is determined by 
the maximum bandwidth of the bus for isochronous transfers: 32 MB/s.  
This rate cannot be exceeded by the combined video streams on the bus. 

Table 2 shows the bandwidth requirements for the DCSG in various modes 
and for various frame rates.  Using this table, it is possible to determine the 
maximum number devices that can stream video simultaneously.  For 
example, at 15 Hz and 640x480 resolution, a maximum of 6 DCSG devices 
can send video information at the same time. 

The bus bandwidth consumed by a device is more than would be expected 
from just counting the number of bytes in each frame, because there are 
blank cycles on the bus, when no data is being transmitted, even though the 
bandwidth is reserved.  Thus, it makes no difference whether the rate is 30 
Hz or 25 Hz, the bus bandwidth consumed is the same. 

Frame Size  Frame rate, 

standard 

Frame rate,  
50 Hz option 

60 Hz 

50 Hz 

30 Hz 

25 Hz 

15 Hz 

12.5 Hz 

640x480 

7.5 Hz 

6.25 Hz 

Table 3-1  Supported frame rates for the 

DCSG, 400 Mbps IEEE 1394 bus. 

Frame 
size 

Bus MB per 
frame - 
stereo 

60 / 50 
Hz 

30 / 25 
Hz 

15 / 12.5 
Hz 

7.5 / 6.25 
Hz 

640x480 

0.342 MB 

20.5 MB 

10.2 MB 

5.12 MB 

2.6 MB 

Table 2  Bus bandwidth requirements at different frame rates. 

Summary of Contents for DCSG

Page 1: ...DCSG USER S MANUAL 2007 VIDERE DESIGN 1 DCSG Digital Video Camera User s Manual 2007 Videre Design...

Page 2: ...9 5 2 Cleaning the Imagers 9 5 3 Imager Size 9 5 4 F Number 9 5 5 Focal Length 9 5 6 Field of View 9 6 1394 Interface 11 6 1 IEEE 1394 Cable 11 6 2 IEEE 1394 Host Interface 11 6 3 Supplying Power 11 7...

Page 3: ...pplication There are software drivers for the DCSG for MS Windows 2000 XP and for Linux 2 4 and 2 6 kernels These drivers are included in a Software Developer s Kit which is bundled with the devices U...

Page 4: ...here is a DCSG present If not go back to software installation Section Error Reference source not found and follow the instructions for configuring the correct capture library Pull down the Input choo...

Page 5: ...no user settable switches on the DCSG 3 1 Hardware Schematic Figure 3 2 shows the design of the internal hardware of the DCSG In the imager module a Micron MT9M001 imager of size 1280x1024 pixels dig...

Page 6: ...IEEE 1394 PC Card or PCI Card defines a separate IEEE 1394 bus The two or three ports on the card all belong to the same bus as does any IEEE 1394 hub connected to these ports Separate PC Cards and P...

Page 7: ...esktop PCs supply power to the bus laptops do not See Section 6 for information about cabling and power for the IEEE 1394 bus 4 1 2 Linux Hardware and Driver Installation Linux kernels 2 4 or 2 6 kern...

Page 8: ...DERE DESIGN 8 libdcap so and dCamera lib dll are the capture libraries for Linux and MS Windows respectively There are several sample applications see the DCAM Digital Camera Capture Software User s M...

Page 9: ...er 5 4 F Number The F number is a measure of the light gathering ability of a lens The lower the F number the better it is at pulling in light and the better the DCSG will see in low illumination sett...

Page 10: ...USER S MANUAL 2007 VIDERE DESIGN 10 Lens focal length Horizontal FOV Vertical FOV 2 8 mm 68 deg 59 deg 4 0 51 42 8 0 27 23 Table 5 1 Horizontal and vertical field of view for different lens focal len...

Page 11: ...IA cards do not have the capability of supplying power and come with an adapter for supplying power to the 1394 cable through a wall transformer Any 1394 card is suitable as long as it conforms to OHC...

Page 12: ...ard with a power port On the right power is supplied through a hub with a power port Power should be 7 to 16 VDC at 2 W Check the PC Card or hub for the type of power connector IEEE 1394 Cables Power...

Page 13: ...is overall neutral called white balance The DCSG C provides manual color balance by allowing variable gain on the red and blue pixels relative to the green pixels Manual balance is useful in many mach...

Page 14: ...lly closed There are automatic modes for both exposure and gain In auto mode gain and exposure are controlled by the host PC which samples the incoming image and sends commands to the stereo device Th...

Page 15: ...e for each of the frame sizes Note that a 50 Hz option is available see Section 3 4 7 6 Firmware Parameters There are several firmware parameter that affect the overall behavior of the DCSG Vertical o...

Page 16: ...DERE DESIGN 16 This ability may be useful for some special applications such as alignment of several cameras The vertical offset is adjusted using the Voff parameter in the firmware dialog Figure 7 3...

Page 17: ...CSG USER S MANUAL 2007 VIDERE DESIGN 17 8 Interface Software API Please see the DCAM Digital Camera Capture Software User s Manual for information about the software API for capturing and saving image...

Page 18: ...Diagram The diagram below shows the physical dimensions for the DCSG C The larger hole is threaded for a 20 machine screw standard tripod mounting screw The two smaller holes are threaded for 6 32 mac...

Page 19: ...r Bayer color pattern Frame Rates 3 75 7 5 15 30 60 Hz 3 125 6 5 12 5 25 50 Hz Exposure 1 line time to full frame Gain 0 18 dB Sensitivity 4 8 V lux sec monochrome Full no yes 3 75 7 5 15 30 60 S N 60...

Page 20: ...DCSG USER S MANUAL 2007 VIDERE DESIGN 20 10 3 Imager Response Monochrome 10 4 Filter Transmittance...

Page 21: ...UAL 2007 VIDERE DESIGN 21 11 Technical Support For technical support please contact Videre Design by email or FAX Videre Design 865 College Avenue Menlo Park CA 94025 Fax 650 323 3646 Email support vi...

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