As stated in the Introduction, the primary objective of the FSM sequential
implementation (SI) was to optimize a sequential cluster identification algorithm
for a subsequent parallel implementation (PI) on the CM-5.
This objective was accomplished by implementing
the HK cluster identification algorithm with efficient use of pointers and utilizing a
finite state machine to eliminate redundant integer comparison operations.
The FSM implementation was compared to the HK implementation in
(Berry et al., 1994) and
Figure 11 illustrates the execution times
for the FSM implementation and that of the original
HK implementation in Berry et al. (1994). The reduction in time
for the FSM implementation can be attributed to the efficient
use of pointers during array indexing, compression of the search path
during cluster merge operations, and the use of a finite state machine to
reduce redundant integer comparison
operations by encapsulating the previous comparison result in a machine state.
The FSM implementation achieved a minimum time improvement of 1.39 and a
maximum time improvement of 2.00 on the FIRE map.
The FORD map was not used for sequential comparisons because the previous
implementation in Berry et al. (1994)
was designed to handle maps smaller than 
pixels.