Our goal is to design and to achieve a multiple purpose vision system for various robotics applications : wheeled robots (like cars for autonomous driving), legged robots (six, four (SONY's AIBO) legged robots, and humanoid), flying robots (to inspect bridges for example) in various conditions : indoor or outdoor. Considering that the constraints depend on the application, we propose an edge segmentation implemented either in software, or in hardware using CPLDs (ASICs or FPGAs could be used too). After discussing the criteria of our choice, we propose a chain of image processing operators constituting an edge segmentation. Although this chain is quite simple and very fast to perform, results appear satisfactory. We proposed a software implementation of it. Its temporal optimization is based on : its implementation under the pixel data flow programming model, the gathering of local processing when it is possible, the simplification of computations, and the use of fast access data structures. Then, we describe a first dedicated hardware implementation of the first part, which requires 9CPLS in this low cost version. It is technically possible, but more expensive, to implement these algorithms using only a signle FPGA.