1. A data stream processing architecture, the data forming matrices of pixels of dimension Nl×Nc, the architecture comprising: processing units, each processing unit being capable of receiving an input data stream and of delivering an output data stream, and each processing unit comprising: a control unit capable of supplying instructions, a set of neighborhood processors capable of performing the instructions received from the control unit and of supplying data forming the output data stream of the processing unit, and a neighborhood storage unit enabling each neighborhood processor to access data of the input data stream received by the processing unit forming a neighborhood of pixels of dimension Vl×Vc, the neighborhoods accessible to the processors being centered on contiguous pixels of one and the same row of a matrix, two processors being neighbors when the neighborhoods that they can access are centered on contiguous pixels in one and the same row of a matrix; and interconnection means capable of receiving a data stream at an input of the architecture and the output data streams of the processing units, and capable of delivering a data stream at an output of the architecture, wherein two processing units can be coupled on a North/South axis and each comprise: one and the same number N of neighborhood processors; and intra-unit connection means enabling each neighborhood processor to exchange data with each of its neighboring processors, so that the neighborhood of pixels accessible to a neighborhood processor can be extended to all the neighborhoods of pixels accessible to the neighborhood processors of the coupled processing unit concerned, said set forming a neighborhood of pixels of dimension Vl×(Vc+N−1); and the architecture further comprises: a storage manager capable of receiving a data stream from the interconnection means and enabling the neighborhood processors of a first coupled processing unit to access neighborhoods of pixels contiguous with the neighborhoods of pixels accessible to the neighborhood processors of a second coupled processing unit, so that the neighborhoods of pixels accessible to the neighborhood processors of the two coupled processing units can form a vicinity of dimension 2·Vl×(Vc+N−1); and connection means on the North/South axis enabling each neighborhood processor of the first coupled processing unite to exchange data with one of the neighborhood processors of the second coupled processing unit, the neighborhood processors being linked in pairs so as to have access to neighborhoods of pixels centered on one and the same column of a matrix, so that the neighborhood of pixels accessible to each neighborhood processor can be extended to the neighborhoods of pixels accessible to the neighborhood processor to which it is linked.