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US 10,319,260 B2Granted
Methods, apparatus and computer program for automatically deriving small-scale maps
OwnerBin Jianginventor
Life of this patent
Estimating the term…
Abstract
One or more small-scale maps are generated automatically and directly from a single large-scale map or database. A subset of geographic features to be represented in the small-scale map is selected based on the scaling law. The geographic features in the subset are determined based on topological connectivity, size, bend size or point density characterizing the geographic features, so the subset includes the larger or more connected or with higher density among the geographic features.
Claims18
A method for generating one or more small-scale maps from a single large-scale map or database, the method comprising, for each of the one or more small-scale maps and for each type of geographic features automatically performing:
- selecting a subset of geographic features to be represented in the small-scale map, wherein a number of geographic features in the subset is determined based on a scaling law, and the geographic features in the subset are determined based on topological connectivity or size or bend size or point density characterizing the geographic features, so as the subset to include larger or more connected among the geographic features;
- generating the small-scale map using the subset made of selected geographic features, while maintaining topological relationships present in the single large-scale map or database among the selected geographic features;
- and
- displaying the generated small-scale map,
- wherein the geographic features characterized by number of connections are split into levels using head/tail breaks, and the topological connectivity T indicating a lowest level of the selected geographic features in the small-scale map with a scale denominator Md is calculated as
- T
- =
- log
- 2
-
- (
- M
- d
- M
- 0
- )
- log
- 2
-
- (
- M
- m
- M
- 0
- )
- ×
- h
-
- (
- c
- )
- where Mo is an original scale denominator of the large-scale map or database, Mm is a denominator of a minimum-scale in a scale series, and h(c) is an ht-index of topological connectivity of all connected geographic features of a certain type.
29 more elements
A map-generating apparatus configured to automatically generate one or more small-scale maps from a single large-scale map or database, the apparatus comprising:
- an interface configured to enable receiving input triggering the one or more small-scale maps to be generated and to output the one or more small-scale maps;
- a data processing unit connected to the interface and configured to perform for each of the one-or more small-scale maps
- selecting a subset of geographic features to be represented in the small-scale map, wherein a number of geographic features in the subset is determined based on a scaling law, and the geographic features in the subset are determined based on topological connectivity or size or bend size or point density characterizing the geographic features, so as the subset to include larger or more connected among the geographic features;
- and
- generating the small-scale map using the subset made of selected geographic features, while maintaining topological relationships present in the single large-scale map or database among the selected geographic features;
- and
- a display device configured to display the generated small-scale map,
- wherein the data processing unit is configured to split the geographic features characterized by number of connections into levels using a head/tail breaks technique, and to calculate the topological connectivity T indicating a lowest level of the selected geographic features as
- T
- =
- log
- 2
-
- (
- M
- d
- M
- 0
- )
- log
- 2
-
- (
- M
- m
- M
- 0
- )
- ×
- h
-
- (
- c
- )
- where Md is a scale denominator of the small-scale map, Mo is an original scale denominator of the large-scale map or database, Mm is a denominator of a minimum-scale in a scale series, and h(c) is an ht-index of topological connectivity of all connected geographic features of a certain type.
32 more elements
A non-transitory computer-readable recording medium storing executable codes which, when executed by a processor having access to a large-scale map or database, generate one or more small-scale maps by performing for each of the one or more small-scale maps and for each type of geographic features:
- selecting a subset of geographic features to be represented in the small-scale map, wherein a number of geographic features in the subset is determined based on a scaling law, and the geographic features in the subset are determined based on topological connectivity or size or bend size or point density characterizing the geographic features, so as the subset to include larger or more connected among the geographic features;
- generating the small-scale map using the subset made of selected geographic features, while maintaining topological relationships present in the single large-scale map or database among the selected geographic features;
- and
- displaying the generated small-scale map,
- wherein the executable codes further make the processor to perform at least one of:
- to split the geographic features characterized by number of connections are split into levels using a head/tail breaks technique, and to calculate the topological connectivity T indicating a lowest level of the selected geographic features in the small-scale map with a scale denominator Md is calculated as
- T
- =
- log
- 2
-
- (
- M
- d
- M
- 0
- )
- log
- 2
-
- (
- M
- m
- M
- 0
- )
- ×
- h
-
- (
- c
- )
- where Mo is an original scale denominator of the large-scale map or database, Mm is a denominator of a minimum-scale in a scale series, and h(c) is an ht-index of topological connectivity of all connected geographic features of a certain type;
- to simplify a selected geographic feature in the small-scale map by using geometric details of levels higher than and equal to G which is calculated as
- G
- =
- log
- 2
-
- (
- M
- d
- M
- 0
- )
- log
- 2
-
- (
- M
- m
- M
- 0
- )
- ×
- h
-
- (
- x
- )
- where h(x) is an ht index of all bends of the selected geographic feature;
- and
- to select point-like geographic features separately, each of the point-like features being associated with a hierarchical level, and point-like geographic features included in the subset having higher hierarchical levels than point-like geographic features not included in the subset, the hierarchical level P being calculated as
- P
- =
- log
- 2
-
- (
- M
- d
- M
- 0
- )
- log
- 2
-
- (
- M
- m
- M
- 0
- )
- ×
- h
-
- (
- ρ
- )
- where h(ρ) is an ht-index of density of point-like geographic features.
87 more elements
A map-generating apparatus configured to automatically generate one or more small-scale maps from a single large-scale map or database, the apparatus comprising:
- an interface configured to enable receiving input triggering the one or more small-scale maps to be generated and to output the one or more small-scale maps;
- a data processing unit connected to the interface and configured to perform for each of the one-or more small-scale maps;
- selecting a subset of geographic features to be represented in the small-scale map, wherein a number of geographic features in the subset is determined based on a scaling law, and the geographic features in the subset are determined based on topological connectivity or size or bend size or point density characterizing the geographic features, so as the subset to include larger or more connected among the geographic features;
- generating the small-scale map using the subset made of selected geographic features, while maintaining topological relationships present in the single large-scale map or database among the selected geographic features;
- and
- a display device configured to display the generated small-scale map,
- wherein the data processing unit is further configured:
- to determine a constant c in a power law y=Nr−c, based on a number y of geographic features of a predetermined type in the subset of a primary-scale map, N being a constant, and r being a primary scale r, and
- to calculate a number y2 of geographic features of the predetermined type of the small-scale characterized by a scale r2 as y2=Nr2−c.
6 more elements
Dependencies are inferred from the claim text.