Patent Document ID: 4734770
Application ID: 07013541
Patent Status: 1

Claim One:
1. An image data processing method for treating first image data consisting of a plurality of pixels having values corresponding to their gray level, several of which contain noise components, and transforming them into second image data, in which the noise components are reduced or eliminated, comprising; a first step for selecting pixels x.sub.i,j, which are objects to be treated, whose gray level value is to be updated, from said first image data; a second step for obtaining candidate values {x'.sub.i,j } for the gray level, which should be given to said object pixels x.sub.i,j on the basis of a function E ({x.sub.i,j }) consisting of a first variable term U.sup.d ({x.sub.i,j }), whose differential with respect to the gray level {x.sub.i,j } of the object pixel is proportional to the Laplacian with respect to the gray level at the position of the object pixel in the image and a second variable term U.sup.n ({x.sub.i,j }), which is proportional to the square of the gray level of the noise components contained in the object pixel; a third step for obtaining q corresponding to the ratio of the probability G ({x'.sub.i,j }) in the case where the gray level of said object pixel x.sub.i,j is replaced by said candidate value {x'.sub.i,j }, using a probability formula G ({x.sub.i,j }) including said function in its exponent, to the probability G ({x.sub.i,j }) in the case where the object pixel x.sub.i,j is held to be the value at that time {x.sub.i,j }; and a fourth step for replacing the gray level of said object pixel by the candidate value {x'.sub.i,j }, according to results obtained by comparing said value q with a random number .eta., said first to fourth steps being performed for all the pixels of said first image data in order to obtain said second image data.