Contour extraction has been used as an image processing scenario to explore the advantages and implications of using the PASM parallel processing system. Use of these parallel algorithms leads to several advantages, notably speedup. Analysis of the algorithms has motivated the inclusion of several important architectural features. These features were used to discuss possible configurations of a custom-designed VLSI processor chip set for PASM. The use of algorithm characteristics to drive the design of PASM leads to a machine with features that provide the necessary flexibility for executing image and speech processing algorithms.