漸層色在地圖表示的應用

Abstract

The development of cartography at the end of nineteen century was essentially influenced by the inventions of photography, lithography, and halftone processing. Combination of hill shading and layer coloring have been the major method of relief presentation on small scale maps since the mid twenty century. It has been the standard method in publishing an atlas due to its efficient visual effect of relief presentation. However, the techniques of map drafting, plate making, and offset printing have been improved by more recent development of photo-grammetry, laser scanner, and computer aided drafting and design. The attempt of this article is to introduce the newly developed gradate coloring to take place layer coloring in relief presentation. Of which, air-brushing is applied in order to let adjacent colors being fused within buffer inbetween, to eliminate distinct boundary and difference of colors, and to facilitate procedure of plate making as well as printing. Laser scanner is applied to have color separations for making plates. As a result, the relief presenta-tion is much improved. The clarity of map symbols are much better than ever. Tremendous time and cost are saved. The overall purposes of this article are: to introduce the application of gradate coloring and its importance to map production; to improve the map quality in this country; to fill out the blank page in cartographic history of China; and to prepare stepping in a new field of computer map production.