M9 CO) CD. e DCD wv "4€ 
ua CD 
EB'ooo5D2 
+ 
image 
sequence 
recall 
  
  
  
figure 
animation 
  
  
  
  
  
  
image 
processing 
   
measurement 
values 
  
  
   
  
    
  
search space 
directives 
    
state 
estimation 
  
  
  
motion parameters 
Fig. 2: Inter-process communication 
2. SYNTHESIS 
The animation tool, which provides flexible means for 
test signal generation, can be looked at in two aspects, 
a geometric and a movement generating one (see 
figure 5). 
  
Fig. 3: Sample input image 
2.1 Geometry 
The figures are regarded as articulated bodies and are 
eometrically represented by volume models and a 
imuied number of limb joints giving a compromise 
between realistic shape and modelli;g effort. The 
model follows major ideas in the wide-spread field of 
computer graphics [Dooley 82, Thalmann 90]. As for 
real human mobility, the body has 107 degrees of 
freedom according to [Fischer 06], not taken into 
account the vertebrae and jaw. Nevertheless, in order 
to achieve a somewhat natural appearance and 
movability less effort is required, but the 
interdepenceny between good-looking movements and 
pleasing body representation has to be borne in mind. 
An adjustable figure repertoire with different shapes 
and scale factors has been created, also clothing 
artefacts are implemented. Figure 4 gives an 
impression of the degree of modelling detail. The limb 
ends are thoroughly modelled such that under no 
circumstances undesireable gaps at joints occur. 
2.2. Movements 
The actual issue of animation - animating objects, i.e. 
let them move - can be performed threefold with the 
existing tool: 
by a kinetik approach (implemented for the 
particularly critical simulation of human gait), 
by kinematic movement description (for less complex 
definition of cyclic movement of arms) and 
by key-frame interpolation (for being able to uniformly 
animate a whole figure and to switch smoothly between 
single movement patterns). 
Firstly, an exclusively kinetic approach is assigned for 
leg movement during normal walking only. Stiffed leg 
locomotion was enhanced by including knee flexion. 
Regarding the stance leg as an inverted pendulum and 
  
Fig. 4: Wire frame rendering of figure specimen