GENERATING RASTER IMAGE REPRESENTING ROAD EXISTENCE PROBABILITY BASED ON PROBE MEASUREMENTS

摘要

The invention comprises methods for enabling digital map database editors to more easily interpret probe measurements by generating raster images which represent road existence probabilities or other attributes of concern such as altitude, speed, acceleration, or direction of movement. The raster images may be imposed on tiles (16, 16', 16", 16'") in a digital map database and use a gradient value, e.g., gray scale brightness, hue or saturation, to visually represent the probability density. Such renderings may utilize brush objects which represent probability density of, for example, vehicle position via a Gaussian probability distribution wherein each value in the brush is a number between 0 and 1 representing the Gaussian probability, with all pixels of that brush summing up to 1. In this manner, a smaller brush sizes visually describes more focused positional distributions whereas a larger brush size represents greater uncertainty and higher positional deviation.