Spatial processing for map geometry simplification

Abstract

A method of simplifying a digital map for display is disclosed. The method comprises receiving a digital map for a geographical region, the digital map being organized into a plurality of raw map tiles associated with a plurality of sub-regions of the geographical region; retrieving configuration data related to visibility to humans for simplifying the digital map; identifying one or more features from each of the plurality of raw map tiles, each feature corresponding to a cluster of pixels, at least two features corresponding to a common pixel; generating a specific modified map tile for a particular raw map tile based on the configuration data by assigning a maximum of all values of pixels of certain features associated with the particular raw map tile that correspond to one or more common pixels to at least one pixel of the one or more common pixels not already having the maximum as a value.

What is claimed is: 
     
         1 . A computer-implemented method of simplifying a digital map for display, comprising:
 receiving, by a processor, a digital map for a geographical region, the digital map being organized into a plurality of raw map tiles associated with a plurality of sub-regions of the geographical region;   retrieving, by the processor, configuration data stored in one or more memories, the configuration data being related to visibility to humans for simplifying the digital map;   identifying one or more features from each of the plurality of raw map tiles,   each feature of the one more features of each of the plurality of raw map tiles corresponding to a cluster of pixels within the raw map tile and having a value for each of the cluster of pixels,   at least two features corresponding to a common pixel within a raw map tile of the plurality of raw map tiles;   creating a plurality of modified map tiles forming a modified digital map for the plurality of raw map tiles based on the configuration data, a total size of the plurality of modified map tiles being smaller than a total size of the plurality of raw map tiles, by eliminating or merging at least one feature in the plurality of raw map tiles, updating a value of a pixel within a feature in the plurality of raw map tiles, or reducing a size of a feature in the plurality of raw map tiles,   the creating comprising generating a specific modified map tile for a particular raw map tile of the plurality of raw map tiles by assigning a maximum of all values of pixels of certain features of the one or more features associated with the particular raw map tile that correspond to one or more common pixels to at least one pixel of the one or more common pixels of at least one of the certain features, the at least one pixel each not already having the maximum as a value;   storing, for each of the plurality of modified map tiles, the modified map tile and an indication of a corresponding raw map tile of the plurality of raw map tiles in the one or more memories.   
     
     
         2 . The computer-implemented method of  claim 1 , further comprising:
 receiving a request for a specific raw map tile of the plurality of raw map tiles;   retrieving, from the one or more memories, a specific modified map tile of the plurality of modified map tiles that corresponds to the specific raw map tile;   transmitting the specific modified map tile in response to the request to a display device.   
     
     
         3 . The computer-implemented method of  claim 1 ,
 the configuration data including data for multiple zoom levels for viewing digital maps of the geographical region,   the digital map corresponding to a zoom level of the multiple zoom levels.   
     
     
         4 . The computer-implemented method of  claim 3 , further comprising
 receiving a selection of a particular zoom level of the multiple zoom levels,   the configuration data including smoothing functions allowing dynamic control of simplification of digital maps, as modified digital maps corresponding to successive zoom levels that have been selected are transmitted to a display device.   
     
     
         5 . The computer-implemented method of  claim 1 , the creating comprising:
 determining that a pixel resolution for a specific raw map tile of the plurality of raw map tiles is below a first threshold from the configuration data;   determining that the specific raw map tile has a specific number of features that is greater than a second threshold from the configuration data;   generating a specific modified map tile for the specific raw map tile by eliminating a feature of the specific number of features.   
     
     
         6 . The computer-implemented method of  claim 1 , the creating comprising:
 determining that a pixel resolution for a specific raw map tile of the plurality of raw map tiles exceeds a first threshold from the configuration data;   determining that the specific raw map tile has a specific number of features including a feature that is larger than a second threshold from the configuration data;   generating a specific modified map tile for the specific raw map tile by updating at least one value of a pixel in the feature.   
     
     
         7 . The computer-implemented method of  claim 1 , the creating comprising:
 computing an aggregate of number of vertices in shapes of features in a raw map tile over a list of neighboring raw map tiles;   selecting a particular raw map tile of the list of neighboring raw map tiles that has a number of vertices in shapes of features within the particular raw map tile that is greater than the aggregate by a particular amount from the configuration data; and   generating a particular modified map tile for the particular raw map tile by reducing the number of vertices in the shapes of the features within the particular raw map tile.   
     
     
         8 . The computer-implemented method of  claim 1 , the creating comprising generating a specific modified map tile for a set of multiple raw map tiles of the plurality of raw map tiles by assigning a maximum of all values of pixels in features within the set of multiple raw map tiles to at least one pixel of the features within the set of multiple raw map tiles, the at least one pixel each not already having the maximum as a value. 
     
     
         9 . The computer-implemented method of  claim 1 , each value of a pixel of a feature within the digital map representing an amount of risk that a certain event of a list of events will take place. 
     
     
         10 . The computer-implemented method of  claim 1 , a pixel resolution of a particular raw map tile of the plurality of raw map tiles depending on a location of the sub-region associated with the particular raw map tile within the geographical region. 
     
     
         11 . One or more non-transitory computer-readable storage media storing instructions which when executed cause one or more processors to perform a method of simplifying a digital map, the method comprising:
 receiving a digital map for a geographical region, the digital map being organized into a plurality of raw map tiles associated with a plurality of sub-regions of the geographical region;   retrieving configuration data stored in one or more memories, the configuration data being related to visibility to humans for simplifying the digital map;   identifying one or more features from each of the plurality of raw map tiles,   each feature of the one more features of each of the plurality of raw map tiles corresponding to a cluster of pixels within the raw map tile and having a value for each of the cluster of pixels,   at least two features corresponding to a common pixel within a raw map tile of the plurality of raw map tiles;   creating a plurality of modified map tiles forming a modified digital map for the plurality of raw map tiles based on the configuration data, a total size of the plurality of modified map tiles being smaller than a total size of the plurality of raw map tiles, by eliminating or merging at least one feature in the plurality of raw map tiles, updating a value of a pixel within a feature in the plurality of raw map tiles, or reducing a size of a feature in the plurality of raw map tiles,   the creating comprising generating a specific modified map tile for a particular raw map tile of the plurality of raw map tiles by assigning a maximum of all values of pixels of certain features of the one or more features associated with the particular raw map tile that correspond to one or more common pixels to at least one pixel of the one or more common pixels of at least one of the certain features, the at least one pixel each not already having the maximum as a value;   storing, for each of the plurality of modified map tiles, the modified map tile and an indication of a corresponding raw map tile of the plurality of raw map tiles in the one or more memories.   
     
     
         12 . The one or more non-transitory computer-readable storage media of  claim 11 , the method further comprising:
 receiving a request for a specific raw map tile of the plurality of raw map tiles;   retrieving, from the one or more memories, a specific modified map tile of the plurality of modified map tiles that corresponds to the specific raw map tile;   transmitting the specific modified map tile in response to the request to a display device.   
     
     
         13 . The one or more non-transitory computer-readable storage media of  claim 11 ,
 the configuration data including data for multiple zoom levels for viewing digital maps of the geographical region,   the digital map corresponding to a zoom level of the multiple zoom levels.   
     
     
         14 . The one or more non-transitory computer-readable storage media of  claim 13 , the method further comprising
 receiving a selection of a particular zoom level of the multiple zoom levels,   the configuration data including smoothing functions allowing dynamic control of simplification of digital maps, as modified digital maps corresponding to successive zoom levels that have been selected are transmitted to a display device.   
     
     
         15 . The one or more non-transitory computer-readable storage media of  claim 11 , the creating comprising:
 determining that a pixel resolution for a specific raw map tile of the plurality of raw map tiles is below a first threshold from the configuration data;   determining that the specific raw map tile has a specific number of features that is greater than a second threshold from the configuration data;   generating a specific modified map tile for the specific raw map tile by eliminating a feature of the specific number of features.   
     
     
         16 . The one or more non-transitory computer-readable storage media of  claim 11 , the creating comprising:
 determining that a pixel resolution for a specific raw map tile of the plurality of raw map tiles exceeds a first threshold from the configuration data;   determining that the specific raw map tile has a specific number of features including a feature that is larger than a second threshold from the configuration data;   generating a specific modified map tile for the specific raw map tile by updating at least one value of a pixel in the feature.   
     
     
         17 . The one or more non-transitory computer-readable storage media of  claim 11 , each value of a pixel of a feature within the digital map representing an amount of risk that a certain event of a list of events will take place. 
     
     
         18 . The one or more non-transitory computer-readable storage media of  claim 11 , a pixel resolution of a particular raw map tile of the plurality of raw map tiles depending on a location of the sub-region associated with the particular raw map tile within the geographical region. 
     
     
         19 . A system for simplifying a digital map, comprising:
 one or more memories;   one or more processors coupled with the memory and configured to perform:   receiving a digital map for a geographical region, the digital map being organized into a plurality of raw map tiles associated with a plurality of sub-regions of the geographical region;   retrieving configuration data stored in the one or more memories, the configuration data being related to visibility to humans for simplifying the digital map;   identifying one or more features from each of the plurality of raw map tiles,   each feature of the one more features of each of the plurality of raw map tiles corresponding to a cluster of pixels within the raw map tile and having a value for each of the cluster of pixels,   at least two features corresponding to a common pixel within a raw map tile of the plurality of raw map tiles;   creating a plurality of modified map tiles forming a modified digital map for the plurality of raw map tiles based on the configuration data, a total size of the plurality of modified map tiles being smaller than a total size of the plurality of raw map tiles, by eliminating or merging at least one feature in the plurality of raw map tiles, updating a value of a pixel within a feature in the plurality of raw map tiles, or reducing a size of a feature in the plurality of raw map tiles,   the creating comprising generating a specific modified map tile for a particular raw map tile of the plurality of raw map tiles by assigning a maximum of all values of pixels of certain features of the one or more features associated with the particular raw map tile that correspond to one or more common pixels to at least one pixel of the one or more common pixels of at least one of the certain features, the at least one pixel each not already having the maximum as a value;   storing, for each of the plurality of modified map tiles, the modified map tile and an indication of a corresponding raw map tile of the plurality of raw map tiles in the one or more memories.   
     
     
         20 . The system of  claim 19 , the one or more processors further configured to perform:
 receiving a request for a specific raw map tile of the plurality of raw map tiles;   retrieving, from the one or more memories, a specific modified map tile of the plurality of modified map tiles that corresponds to the specific raw map tile;   transmitting the specific modified map tile in response to the request to a display device.