1. A system for recognizing features in an image comprised of wavefronts of radiated energy, each point in the image being characterized by a plurality of radiated energy intensities at different predetermined wavelengths and a height, comprising: sensor means operable to receive the radiated energy from preselected points in the two-dimensional image in a predetermined order, thereby defining picture elements, and to produce a plurality of signals measuring the radiated energy intensities and height within each picture element; filter means for filtering the signals produced by the sensor means and adapted to produce a plurality of signals measuring the radiate energy intensity within each picture element at each of the predetermined wavelengths; processing means adapted to receive the signals produced by the sensor means and to produce a signal measuring the height associated with each picture element; first classification means adapted to receive at least some of the plurality of signals produced by the processing means and the filtering means, to partially classify each of the picture elements according to a first predetermined classification criterion selected from the set of classification criteria including the distribution of the plurality of radiated energy intensities within each picture element, and the distribution of the height associated with each picture element, the criterion selected being that which minimizes the number of picture elements partially classified and to produce a signal indicative of the resulting partial classification; and second classification means adapted to receive the signal indicative of the resulting partial classification produced by the first classification means, operable to further classify, according to the remaining criterion of said set of classification criteria, the picture elements partially classified by the first classification means into classes containing the features to be recognized, and to produce signals indicative of which picture elements have been further classified.