Curved Baseline Generation for Map Labeling

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Solution Overview

Problem

Portable GPS devices face performance issues due to the computational burden of generating curved labels for map polylines, which are often complex and require efficient methods to prevent overcrowding and ensure visual clarity.

Innovation Solution

A method and apparatus for generating a curved baseline on portable GPS devices using a curved baseline generator module that processes polyline data to produce B-Spline points, allowing for efficient and visually clear labeling of map objects like roads and rivers.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If curved labeling is used to faithfully represent polylines, then visual clarity and labeling accuracy are improved, but computational time and processing burden increase significantly

Engineering Contradiction:

Improvelabeling accuracyVSAvoidcomputational time

Core Design Contradiction:

Manufacturing precisionVSLoss of time

Solution Approach 1:

The patent segments the complex curved baseline generation problem into three distinct phases: (1) generating a supporting polyline from the original polyline points, (2) creating control points for B-Spline curves, and (3) generating the final curved baseline. This segmentation allows each phase to be optimized independently, reducing overall computational complexity while maintaining labeling accuracy.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent transforms the geometric representation parameters by converting original polyline points into a new set of control points that define B-Spline curves. This parameter transformation enables the curved baseline to be generated more efficiently using mathematical curve fitting rather than direct geometric computation, reducing computational time while preserving visual fidelity.

Inventive Principle:

Principle #35Parameter changes

2Quantity of substance

If more data is presented on the map display, then information completeness is improved, but screen overcrowding and visual clutter increase

Engineering Contradiction:

Improveinformation completenessVSAvoidvisual clutter

Core Design Contradiction:

Quantity of substanceVSObject-generated harmful factors

Solution Approach 1:

The patent applies curvature to the baseline of text labels, allowing them to follow the natural curvature of map features like roads and rivers. This curved baseline technique enables labels to be positioned more efficiently along curved features, reducing the need for additional spacing and preventing screen overcrowding while maintaining complete information display.

Inventive Principle:

Principle #14Spheroidality (Curvature)

3Productivity

If straight line baseline labeling is used for simplicity, then computational efficiency is improved, but visual clarity and faithfulness to original polylines deteriorate

Engineering Contradiction:

Improvecomputational efficiencyVSAvoidvisual clarity

Core Design Contradiction:

ProductivityVSManufacturing precision

Solution Approach 1:

The patent introduces B-Spline control points as an intermediary between the original polyline data and the final curved baseline. These control points serve as a mathematical mediator that enables smooth curve generation through standardized algorithms, achieving visual clarity comparable to complex geometric methods while maintaining computational efficiency through established B-Spline mathematics.

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentUS7692655B2Apparatus and method of generating curved baseline for map labeling

Publication Date: 2010.04.06 MITAC INT CORP

AI summary

Apparatus and methods of generating a curved baseline for a map labeling include receiving a polyline P={p1,p2, . . . ,pn} of n points, generating a supporting polyline Q={q1,q2, . . . , qm} (m≧n) of m points at an expected distance d between polyline P and a curved base line L. A predetermined number of B-Spline points is generated based upon supporting polyline Q. The B-Spline points are then connected to form a curved baseline L for displaying a label.