A method of converting image outlline data representative of segments defining an outline of an image area to be reproduced, into dot data representative of image dots which collectively represent the image area. In the method, the outline of the image area is superimposed on a coordinated pixel screen wherein a plurality of vertical pixel lines and a plurality of horizontal pixel lines cooperate to provide intersections defining a matrix of dot positions which are selectively used as the image dots. The vertical and horizontal pixel lines form a plurality of sections each having four corners defined by the respective four intersections of the pixel lines. Each one of the plurality of sections is determined as a relevant section if any one of the segments of the outline of the image area passes through the relevant section. The dot data are prepared such that the dot data represents the presence of the image dot at a predetermined one of four corners of each relevant section.