The images are indexed by number
imagec_##_##.ppm -- the first set indexes the 
time and the second the cameras #.  


The camera format is as follows

f -- location of camera
c -- lookat point
u -- up vector
r -- right vector

(f-c) cross (u) = r

m is a effectively a focal length parameter
the units for this parameter are units/pixels

the focal length in pixels is 
length(f-c)/m -- and is somewhere between 400-550 pixels for most cameras

And example cameras file

f
  x 87.91685   y 154.99222   z 63.05293

c
  x 80.49792   y 105.60966   z 60.53860

u
  x 0.00381   y -0.05142   z 0.99867

r
  x -0.98892   y 0.14799   z 0.01140

m
0.09070