[comp.graphics] BANDWIDTH COMPRESSION OF VIDEO or SSTV - less than 2400 baud :

rg@msel.unh.edu (Roger Gonzalez) (03/19/91)

I need to get some pointers toward the state-of-the-art in image
compression for transmission over extremely low bandwidth links.
What are the research areas?  What techniques have proven the best?

On video end:

  68020 VME board with coproinker, Datacube Digimax and ROIstore
  can digitize up to 512x512x8 bits grayscale.

Transmission methods:

  RF and underwater acoustic modems

Receiving end:

  80[2-4]86 with Super VGA

The MAPS technique has been previously applied here at the lab, but this
only allowed 90x90x4 pixels over a 9600 baud link at a SSTV rate.  Since
9600 is a little unrealistic at present, and I will need to do a working
demo of a underwater robot transmitting images back to base, and s-o-t-a
for underwater acoustics is sub-1200 baud, I need a better technique.
How good are differential techniques?  Can differential techniques be
combined with compression?

I really could use some tips.. I have no lack for enthusiasm or interest,
but my background in image processing is lacking and I don't want to
redo any false trails...

Thanks,
Roger

-- 
"The question of whether a computer can think is no more interesting
 than the question of whether a submarine can swim" - Edsgar W. Dijkstra 
rg@[msel|unhd].unh.edu        |  UNH Marine Systems Engineering Laboratory
r_gonzalez@unhh.bitnet        |  Durham, NH  03824-3525