Abstract
This paper presents the evolution of algorithms implementation in image processing libraries and discusses the limits of these implementations in terms of reusability. In particular, we show that in C++, an algorithm can have a general implementation; said differently, an implementation can be generic, i.e., independent of both the input aggregate type and the type of the data contained in the input aggregate. A total reusability of algorithms can therefore be obtained; moreover, a generic implementation is more natural and does not introduce a meaningful additional cost in execution time as compared to an implementation dedicated to a particular input type.