顾及形变控制的小屏幕变比例尺交通路线图生成方法

用户在旅游或者室外运动中经常将路线图显示于移动设备上以方便规划路线。然而移动设备显示屏幕通常较小,若较大范围的地图通过等比例尺缩小在小屏幕显示,可能会导致清晰度和辨识度的降低,尤其对于地图中地物较为密集的区域。本文提出一种自动化生成变比例尺地图的方法,通过更加均匀化地图显示内容密度分布以改善地图概览清晰度。在该方法中,首先对密度分布进行估计,密度估计主要考虑地图上路线空间分布以及地标与注记显示空间,然后根据所得到的密度分布进行变比例尺转换,最终生成的变比例尺结果图,其大小取决于给定显示尺寸。相较于现有变比例尺转换方法,本文提出的方法可以考虑了地标与注记显示空间,同时又能有效控制地图变形以提高地图识别。实验结果表明,通过本方法生成变比例尺结果图对地图概览的清晰度有着显著提高,并且能够保持良好的地图识别度。

Generation of Variable-Scale Route Maps with Consideration of Distortion Reduction for Small Display Sizes

Currently route maps are often displayed on mobile devices for the route selection. However, for such devices, a major problem is their small display sizes. In this study, a new method on adaptive generation of variable scale maps for small display sizes was proposed and aimed to improve the clarity of the whole map. This method consists of two steps, i.e. estimating the density of global distribution on maps and conducting variable scale transformation based on the estimated density values. Compared with current variable scale methods, this method considered the space for representation of the landmarks and text symbols, and the reduction of overall distortions arising from map deformation. The experimental results indicated that the new method is able to adaptively generate the variable scale maps for different small display sizes and provide a map overview with an improved clarity as well as well-preserved map recognition compared with original shapes.