Building Shadow Generation from Raster Imagery
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing map generation techniques using high resolution imagery are computationally intensive and produce inaccurate, noisy shadows when using lower resolution raster imagery, resulting in lower quality maps.
Innovation Solution
A map generation system that extracts and processes pixel values from raster images to create a shadow layer with a shape corresponding to building shapes, conserving processing resources while improving shadow accuracy by translating and modifying pixel values based on building height and shape.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If high resolution imagery (LIDAR) is used to generate building shadows, then shadow accuracy is improved, but processing resources and computational intensity increase substantially
Solution Approach 1:
The patent extracts only the shadow-relevant pixel values from raster imagery using predefined range filtering, rather than processing entire high resolution LIDAR datasets. This extraction approach retrieves shadow information from lower resolution imagery without requiring substantial processing resources, resolving the contradiction between shadow accuracy and processing complexity
Solution Approach 2:
The patent creates a shadow layer that copies and processes only the necessary shadow pixel data from raster imagery, rather than working with complete high resolution imagery. This copying strategy maintains shadow representation quality while significantly reducing computational requirements compared to processing full LIDAR datasets
2Device complexity
If lower resolution raster imagery is used to generate building shadows, then processing resources are conserved, but shadow accuracy deteriorates due to noise and speckle
Solution Approach 1:
The patent applies local quality enhancement by translating shadow pixels based on building height information and applying morphological operations specifically to shadow regions. This localized processing improves shadow accuracy in critical areas without requiring global processing of entire high resolution images, maintaining resource efficiency while enhancing shadow quality
Solution Approach 2:
The patent performs preliminary filtering of pixel values within predefined ranges before further processing, and applies building height-based translations to correct shadow positioning early in the processing pipeline. These preliminary actions reduce noise and speckle before final shadow layer generation, improving accuracy without substantial additional processing resources
Data Source
AI summary
A map generation system, method and computer program product are provided to generate a shadow layer from a raster image that accurately represents the shadows of one or more buildings. In the context of a map generation system, the map generation system extracts pixel values from a raster image of one or more buildings and processes the pixel values so as to retain pixel values within a predefined range while eliminating other pixel values. The pixel values that are retained represent a shadow. The map generation system also modifies the a representation of the shadow by modifying the pixel values of respective pixels so as to have a shape corresponding to the shape of the one or more buildings. The map generation system causes presentation or storage of the building layer representing the one or more buildings and a shadow layer representing the shadow.