26 or 28 connected thereto for receiving the output of the respective control units the demultiplexers 24 26 and 28 respectively effect a distribution of the addresses according to the operating states write in read out image processing of the image memories 30 31 and 32 an angle dependent control unit 22 is additionally connected to the control unit 21 for angle dependent control of the write in address control unit 23 the data are thus converted to angle independent information of predetermined functional dependency this dependency may for example be given by the function 1 cos u03b1 whereby 2 u03b1 is the entire sector angle as shown in fig3 a data reduction is effected by means of this conversion a preferred embodiment of the angle dependent control unit 22 is depicted in fig7 during the sequential transfer of data into the matrix of any of the memories 30 31 32 the write in address of the address control unit 23 will be incremented in each instance the value of the increment is determined in dependence of the angle 34 u03b1 34 according to the following equation wherein the word 34 pixel 34 34 picture element 34 stands for 34 memory element 34 the angle information is derived from the sector scan control unit 21 and fed into a unit 122 is.