×

Method of and arrangement for image data compression by means of a neural network

  • US 5,005,206 A
  • Filed: 11/20/1989
  • Issued: 04/02/1991
  • Est. Priority Date: 11/25/1988
  • Status: Expired due to Fees
First Claim
Patent Images

1. A method used in an arrangement for image data compression by vector quantization in accordance with a precoding in blocks constituted by a plurality of picture elements, thereafter comparing by means of a neural network precoded blocks with reference words stored in the form of a code book in the neural network so as to transmit to a receiver selected indices corresponding to the index of the reference words nearest to the precoded blocks, characterized in that it includes a stage of generating an adaptive code book by means of the neural network, the stage comprising the following steps:

  • A--feeding the neural network with prototypes which prescribe the states of stable neurons in the neural network which determines its synaptic coefficients associated with each prototype during the learning phases,B--resolving by means of the neural network with the aid of test vectors supplied by the pictures by effecting in accordance with consecutive dynamic relaxation phases performed by feeding back the input to the output of the neural network, after which the states of the neurons are stabilized in configuration denoted attractors around which the test vectors are grouped in clouds,C--comparing each test vector with its corresponding attractor, with determination of the distance by which they are separated from each other and determination of the rate of frequentation of each attractor by the test vector,D--determining the rough mean of all the distances;

    and when this rough mean exceeds a predetermined value, selecting attractors whose rate of frequentation exceeds a predetermined rate, thereafter determining the centre of gravity of the total cloud existing around each selected attractor to generate an optimum attractor when this attractor is the better and preserve the old attractor in the opposite case so as to form a group of new attractors which are then used again as new prototypes to restart the method of step A,and when this rough mean is less than the predetermined value, to utilize all the final attractors, to form the reference words of the adaptive code book which are stored in a synaptic coefficients store of the neural network, said reference words being transmitted to the receiver to update its local code book,the method also including a coding stage utilizing the said reference words to encode the rough image and thereafter to select the indices to be transmitted.

View all claims
  • 1 Assignment
Timeline View
Assignment View
    ×
    ×