Analytical Services

Graphics Modeling & Analysis

Like many graphics, maps are printed with a combination of fine solid figures (think of roads) and halftone regions, that is, shaded areas constructed from a fine pattern of tiny, regularly spaced, solid dots. 

A government customer had the problem involving digitally scanning printed maps, automatically separating the solid figures from the shaded ones, and determining the “smoothed” shade that someone’s eyes would see from those fine dots, when reading the map.  This would let the automatic processing distinguish the yellow shading of deserts from the blue of open water or the black relief of mountains. 

We modeled the process of printing a map from all of the color and smooth shading components, or “separations”, which a mapmaker would have used.  Then we designed and implemented algorithms to reverse the process, starting from the scanned map images and ending with every separation that was used in it, exactly what the customer needed.  In fact, the algorithms could even distinguish the fine dots of halftones from equally fine features of other sorts.

For more information on this project or any other services available from STAR Analytical Services, please contact us by email at info@STARAnalyticalServices.com or phone 781-861-STAR (7827).