1. A device for segmenting, under the control of a sequencing stage for furnishing corresponding control signals, a received textured image on the basis of digital signals which are representative thereof, the segmenting including characterizing each texture by representative parameters and image decomposition into regions having different textures; said device comprising: for characterization of texture, a first sub-assembly following by a second sub-assembly; the first sub-assembly including means for generating a directionally morphologically filtered signal and a difference between said received image and said directionally morphologically filtered signal; the second sub-assembly including means for determining texture parameters of said filtered image by computing a morphological gradient from said difference; and for regional decomposition of the filtered image, a third sub-assembly at the output of said second sub-assembly; said third sub-assembly including means for image segmentation of the morphological gradient by the technique of extracting watershed lines.