Method for the spatial filtering of the noise in a digital image, and device for carrying out the method

A device for assistance in the observation of a medical image, comprising:

• a system for supplying data of an image in the form of a two-dimensional matrix of pixels having digitized intensity values,
• a display system for displaying the image,
• an image processing system having access to the image data and to the display system, which image processing system is configured for spatial filtering of the noise in an image (J) in the form of a matrix of pixels ›P(x,y)! having noisy digitized intensity values ›I(x,y)!, and comprises:
• a) means for selection, in a sliding window ›WD(x.sub.0,y.sub.0)! centered around an instantaneous pixel ›P.sub.0 (x.sub.0,y.sub.0)!, of a number (N.noteq.0) of random oriented elementary filters ›F.sub.1, F.sub.2, . . . ;
• V.sub.1, V.sub.2, . . . ! having supports with an axis of orientation axis ›P.sub.0 Z.sub.1, P.sub.0 Z.sub.2, . . . P.sub.0 Z.sub.N ! passing through the instantaneous pixel and having characteristics, one or several of which have random values, and
• b) means for combination of the intensities of pixels on said supports individually, yielding an elementary intensity, and combination of the elementary intensities, yielding a filtered intensity ›R.sub.0 (x.sub.0,y.sub.0)! to be applied to the instantaneous pixel.