Patent Document ID: 4449193
Application ID: 06256929
Patent Status: 1

Claim One:
1. A device for the bidimensional correlation between a reference image of a plane Oxy having lines oriented in the Ox direction and a scanned image obtained by scanning in the plane Oxy, the scanned lines being parallel to Ox, wherein said device comprises: a correlation means including a surface wave convolver said correlation means connected to receive first signals corresponding to said reference image and second signals corresponding to said scanned image with said reference image being formed from K lines of M points and said scanned image being formed from L lines of N points, in which L&gt;K and N&lt;M, wherein the K lines of the reference image are correlated line-by-line with all the systems of K lines such as i at i+k-1 of the scanned image in which 1 is less than or equal to i less than or equal to L minus K, whereby one line of the reference image is simultaneously inputted with one line of the scanned image in order to supply to said correlation means an electrical representation of a monodimensional correlation line formed from points corresponding to the displacement of said reference image and said scanned image thus supplying after summation for a same displacement .alpha. along Ox, (L-K) correlation lines of (M-N) points, wherein said first signals corresponding to the reference image are stored in a first pair of random access memories and said second signals corresponding to the scanned image are each stored in a second pair of random access memories which are read under the control of a clock with one of said first and second signals being read along Ox and the other of said first and second signals being read in the opposite direction along Ox; digital to analog converter means connected to said random access memories for receiving the output of said random access memories; modulation means for receiving the output of said digital-to-analog converter means and supplying a modulated signal placed on a frequency carrier f.sub.O to said correlation means; demodulation means for demodulating the output of said correlation means and applying said demodulated signal to an analog-digital converter; adder means which adds the output of said analog to digital converter and which thereby adds the signals for the points corresponding to one and the same displacement for said (M-N) monodimensional correlation lines of said reference image and said scanned image with the output of said adder means supplying a bidimensional correlation signal whereby said device for bidimensional correlation supplies a new bidimensional correlation line after each new scanned line of the image obtained by scanning.