Due to the various devices composing a smart camera system, various languages have to be known by the designer (like HDL and C/C++). Most of vision applications designers are software programmers and do not have a good knowledge of HDLs (VHDL). This paper presents a new high-level methodology for implementing vision applications on smart camera platforms. This methodology is based on a soft-core approach to manage the whole system and a dataflow (actor-oriented) language to design the processing elements. We discuss in particular interfacing constraints. Keywords-Soft-core, methodology, smart camera, heterogeneous platforms, CAL, processing elements;