[Elphel-support] Line scan mode

[support-list]

---- On Tue, 04 Jun 2013 01:54:03 -0700 Hotmail  wrote ---- 


 > I understand that in line-scan mode the 353 can build an 8000 line maximum image but that each scan is two pixels high. 
 > That should mean the camera performs 4000 scans to make the 8000 line image - correct? 
Yes, if you program each scan to be a 2-line one. This mode was designed primarily for the "linescan", but while 2 is minimal number, you can use wide scans - it actually is useful if you try to get the top FPS with very small frames, because each frame requires CPU activity to generate headers, Exif data. When you combine a number of small frames in a single large one, the Exif data is generated only once and you can achieve higher FPS.

 >  
 > The 353 scans "2300 lines per second Max."  Is that 2300 single pixel high lines or 2300 two pixel high lines? 
It is not possible to make a single line scan, and additionally there is a minimal number of vertical blank lines that take time but do not produce output. I need to check, but as far as I remember minimal total number is 8 (maybe 10), so if you scan 4 lines instead of the 2, one scan will take  (4+8)/(2+8) longer, not twice longer.
 >  
 > How much storage space does each 2536 pixel X 8k frame require as part of a video file? 
Depends on image quality, but generally the frame size is just proportional to the number of pixels.
 >  
 >  
 > Can the 353 be configured with internal HDD, GEO ( compass & GPS ), and stereo options simultaneously. 

Yes, these options are rather independent. I would also recommend to use IMU (or IMU with integrated compass that is now available from Analog Devices). Compass along does not provide much of the useful information if not paired with the IMU.
 > What is the maximum distance the two sensors of a stereo configuration can be separated without problems.
There are several limitations - one is the length of the cables to the sensors, the other depends on your application/software. The larger the distance - the more distant objects produce measurable disparity on the two images, but it makes more difficult to match features on the near objects.

Andrey