[Elphel-support] linescan mode

[Michael Aschauer]

good news! I'll try to test that asap.

m,-



Andrey Filippov schrieb:
> On Thu, Feb 4, 2010 at 7:35 AM, Michael Aschauer <m at ash.to 
> <mailto:m at ash.to>> wrote:
> 
>     Andrey,
> 
>     I currently failed to downgrade.
>     Does that mean this mode should work in 7.1.x firmware? or things
>     are less likely to break?
> 
> 
>     best,
>     m,-
> 
> Michael,
> 
> I will need to test the code some more (current version is really 
> experimental and have some glitches), but it seems that the lines can 
> mode is back in 8.0.6.6 firmware. It supports up to 16K of lines in each 
> composite frame (frames are supposed to perfectly match - no gaps 
> between them). With full line of 2592 pixels the regular 5MPix sensor of 
> the 353 camera can handle about 2500 line pairs (they go in pairs as the 
> sensor is color) per second.
> 
> The same mode should be useful to get the top fps for small images 
> avoiding the CPU overhead related to the file headers and just 
> processing the frame interrupts. It is possible now to combine multiple 
> small images (not just 2-line rectangles) to the total height of up to 
> 16K lines in a single composite image.
> 
> Here are some samples (original and some - rotated/cropped):
> 
> http://community.elphel.com/pictures/linescan/
> 
> It is fun that cars going in the opposite directions on the freeway are 
> going the same direction on the image. You may also notice something 
> like huge chromatic aberration - it is caused by the car crossing one of 
> the line in a color pair before the other.
> 
> Many images are acquired at reduced rate (they have "582lps" in the 
> name) so the cars look more proportional, at the full 2425 lp/s they 
> look too long.
> 
> Andrey