Vector-Raster Overlay Analysis via Edge Clipping
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Solution Overview
Problem
Current vector-raster overlay analysis methods in GIS require significant computational resources and result in accuracy loss when converting vector data to raster data, leading to inconsistencies in polygon edges and surface area calculations.
Innovation Solution
A method and system for vector-raster overlay analysis based on edge clipping, which involves collecting raster and vector datasets, identifying four-coordinate extremums, finding the smallest raster slice covering the polygon, cropping the polygon using an outer rectangle, and allocating pixel attribute values based on area ratios, to accurately calculate the ground surface image area.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If full vector calculation is adopted for overlay analysis between vector data and raster data, then measurement precision is improved, but use of energy increases significantly
Solution Approach 1:
The patent segments the vector polygon into multiple triangular sub-polygons and divides the raster data into slices corresponding to each triangle. This segmentation allows the calculation to be performed on smaller, more manageable units rather than the entire vector-raster dataset, reducing computational energy while maintaining precision through systematic processing of divided portions.
Solution Approach 2:
The patent performs overlay calculation only on the portion of raster data that actually intersects with the vector polygon, rather than processing the entire raster dataset. By identifying and calculating only the relevant intersecting areas (partial action), the method significantly reduces energy consumption while preserving measurement precision for the areas of interest.
2Productivity
If vector data is converted to raster data for overlay analysis, then productivity is improved, but measurement precision deteriorates
Solution Approach 1:
Instead of converting vector data to raster data (the conventional approach), the patent inverts the process by converting raster data to vector format. This allows the overlay analysis to be performed on vector data with precise geometric properties, maintaining measurement precision while achieving productivity improvements through efficient vector-based calculation algorithms.
Solution Approach 2:
The patent changes the data format parameter from raster to vector representation. By transforming the raster data into vector polygons and performing overlay operations in the vector domain, the method preserves the geometric precision of vector data while enabling efficient computational processing through parameter-based calculations rather than pixel-by-pixel operations.
3Ease of operation
If pixel center point attribution or area dominance method is used for raster conversion, then ease of operation is improved, but manufacturing precision deteriorates
Solution Approach 1:
The patent replaces the mechanical attribution methods (pixel center point or area dominance) with a mathematical calculation system. Instead of assigning raster values based on simple geometric rules, the method uses area ratio calculations of intersecting polygons to determine attribute values, providing higher precision while maintaining ease of operation through automated computational procedures.
Data Source
AI summary
A method and a system for vector-raster overlay analysis of a ground surface image area based on edge clipping are provided. A large amount of computing resources is required during the calculation of extracting a ground surface image area using the vector-raster overlay analysis and a loss of accuracy is resulted when vector data is converted into raster data, thereby leading to the issue of calculation error of a polygon surface area. The disclosure adopts the vector-raster overlay analysis method while cropping an edge vector polygon of the ground surface image to be measured and allocating an attribute value of the image according to a pixel, so as to accurately calculate the ground surface image area without drastically increasing the amount of calculation, thereby achieving the function of improving the accuracy and efficiency of calculating the ground surface image area.