In a data processing method, all information on a figure to be drawn, as vector-graphic data representing said figure, is transmitted to a drawing apparatus. The vector-graphic data is processed to form an image, as raster-graphic data representing the figure, and the run length data is extracted from the image. The run length data is grouped to become grouped run length data, and outline vector-graphic data, that is having a smaller data amount than that of the vector-graphic data, and that is based on an outline of the figure represented by the grouped run length data, is created. In another data processing method, the drawing data is processed in a workstation such as a CAD system, and the resulting outline vector graphic data is transmitted to the drawing apparatus.
