Depth Acquisition With Visible-Light Edge Correction at Boundaries

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Solution Overview

Problem

Existing depth acquisition devices struggle to accurately measure distances at boundaries between objects with different reflectivities due to changes in light reflectivity, leading to noise and inaccurate depth measurements.

Innovation Solution

A depth acquisition device that uses a combination of infrared and visible light imaging to detect edge regions perpendicular to the direction of movement, correcting depth images by using edge regions to reduce noise and improve accuracy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a light source irradiates the subject with light and the imager images the light reflected on the subject to convert pixel values into depth, then depth acquisition is achieved, but measurement precision deteriorates at boundaries between objects with different reflectivities

Engineering Contradiction:
Improvedepth measurement accuracyVSAvoidnoise at boundaries
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent introduces a boundary region detector that identifies boundary regions in the visible light image, and uses these boundary regions as intermediary information to correct depth values in the depth image. The boundary region detection serves as a mediator between the visible light image and depth image, allowing precise depth measurement at boundaries by using boundary information from the visible light image to correct inaccurate depth values obtained from infrared light imaging.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent changes the parameter approach by detecting boundary regions based on movement information from visible light images and using this to modify depth values. The system identifies boundary regions where movement occurs and corrects depth values in these specific regions, effectively changing how depth is measured at boundaries by using movement-based boundary detection to guide depth correction.

Inventive Principle:
Principle #35Parameter changes

2Device complexity

If the device uses only infrared light imaging for depth acquisition, then the system is simple, but measurement precision deteriorates due to reflectivity changes at boundaries

Engineering Contradiction:
Improvesystem complexityVSAvoiddepth measurement accuracy
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent merges infrared light imaging and visible light imaging into a single system. The imaging element captures both infrared light (for depth measurement) and visible light (for boundary detection and correction). This combination allows the system to maintain simplicity while improving measurement precision by using visible light information to correct infrared-based depth measurements at boundaries.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The imaging element is designed with multi-functionality, serving both as an infrared detector for depth acquisition and as a visible light detector for boundary region detection. This universal component performs multiple functions: capturing infrared light for depth measurement, capturing visible light for boundary detection, and providing movement information for boundary identification, thereby reducing overall system complexity while improving precision.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Measurement precision

If the device corrects depth images using visible light edge detection, then measurement precision improves at boundaries, but device complexity increases

Engineering Contradiction:
Improvedepth measurement accuracyVSAvoidprocessing complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent segments the image processing into distinct functional regions: boundary region detection, movement information extraction, and depth value correction. By segmenting these functions and processing them in sequence, the system manages processing complexity through structured organization. The boundary region detector first identifies relevant regions, then the correction unit processes only those specific regions, avoiding the need to process the entire image and reducing overall computational burden.

Inventive Principle:
Principle #1Segmentation

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The device effectively reduces noise and enhances the accuracy of depth measurements at boundaries by correcting depth images based on visible light edge detection, ensuring precise distance calculations.

Implementation Method 1

a light source that emits light; an imaging element that images light reflected on the subject

Methodology Applied
Scientific EffectInfrared radiation: Infrared Radiation

Implementation Method 2

light reflected on the subject

Methodology Applied
Scientific EffectReflection: Reflection

Implementation Method 3

an imaging element that images light reflected on the subject

Methodology Applied
Scientific EffectPhotoelectric effect: Photoelectric Effect

Data Source

PatentEP3859394B1Depth acquisition device, depth acquisition method, and program
Publication Date: 2025.08.27 PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO LTD
  • EP3859394B1 patent drawingFigure 1
  • EP3859394B1 patent drawingFigure 2
  • EP3859394B1 patent drawingFigure 3

AI summary

A depth acquisition device (1) capable of accurately acquiring a depth of a subject of an image includes a memory (200) and a processor (110a). The processor (110a) performs: acquiring, from the memory (200), intensities of infrared light which have been emitted from a light source and are measured by imaging performed by receiving the infrared light reflected on a subject by pixels in an imaging element; generating a depth image by calculating a distance to the subject as a depth for each pixel based on an intensity received by the pixel; acquiring, from the memory (200), a visible light image generated by imaging a substantially same scene as that of an infrared light image, with visible light from a substantially same viewpoint and at a substantially same timing as those of imaging the infrared light image which is generated by the imaging based on the intensities of the infrared light received by the pixels; detecting, from the visible light image, an edge region including an edge along a direction perpendicular to a direction of movement of the visible light image; and correcting, in the depth image, a depth of a target region corresponding to the edge region in the depth image.