In this method, the pictures are processed in blocks whose dimensions (H,V) expressed in a number of pixels are integral powers of two, and the contents (pixels) of the different blocks are stored in the memories one after the other. The device for calculating the position of a pixel in the memory from the position x, y of the said pixel in the picture is formed by two material operators 11, 12 which extract from x and y, respectively, the most significant bits m and p, m and p being the integers such as 2.sup.m =H and 2.sup.p 32 V, a multiplier 19 multiplying the number of blocks in a picture line NBLOCH by the vertical component ADBLOCV supplied by the operator 12, and an adder 20 which adds together the result supplied by the said multiplier and the coordinate ADBLOCH supplied by the operator 11.