简介:Acontourtreeisagoodgraphicaltoolforrepresentingthespatialrelationsofcontourlinesandhasmanyapplicationsinmapgeneralization,mapannotation,terrainanalysis,etc.AnewmethodforgeneratingcontourtreesbyintroducingaVoronoi-basedinterioradjacencyconceptisproposedinthispaper.Theimmediateinterioradjacencysetisemployedtoidentifyallofthechildrencontoursofeachcontourwithoutcontourelevations.Ithasadvantagesoverexistingmethodssuchasthegeometricmethodandtheregiongrowingbasedmethod.
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简介:<正>随着科学技术的发展和进步,常规地图生产工艺正朝着以软代硬、以轻代重、以薄代厚的方向迈进,薄膜在地图生产过程中扮演了软、轻、薄的角色,它还具有透明度高、伸缩性小、便于携带、易于保管等特点,因而在地图生产过程中得到了充分应用。制图作业中,常常由于制作地图的工艺方案不同,制图人员经常会碰到薄膜图的拼贴问题。例如,为了制作1∶50000图幅的地理底图,通常需要将四幅放大编绘好的1∶25000图幅经照相缩小而成为1∶50000薄膜图,拼贴到已展绘好1∶50000数学基础的薄膜上;再如,对具有相同地理要素的系列专题图件,可将编绘并复制好的薄膜地理底图和薄膜专题图件套合起来拼贴制成多种专题图件的综合版,然后进行复制,提交验收及清绘出版原图。薄膜图的拼贴质量直接关系着成图质量,所以确保薄膜图的拼贴质量是制图人员面临的实际问题。下面谈谈我们的做法和体会。