AR Optical System Local Opacity Adjustment for Bright Object Contrast

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Solution Overview

Problem

Augmented and merged reality visualization technologies face challenges with color distortion due to limitations in image mixing and overlay, particularly affecting bright objects like well-illuminated brain tissue, resulting in low contrast and reduced perceivability of digital information in AR/MR environments.

Innovation Solution

An optical system that includes a display module, sensor, and processing module to sense optical properties of objects, determine visual contrast, and selectively adjust illumination or optical attenuation to enhance the contrast between the visual overlay and the object, using a camera for image analysis and controlling illumination or attenuation to improve perceivability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of information

If semi-transparent mirrors and projection devices are used to overlay digital images on the field of view, then augmented reality visualization is achieved, but color distortion and low contrast occur for bright objects

Engineering Contradiction:
Improveperceivability of digital informationVSAvoidbrightness of real objects
Core Design Contradiction:
Loss of informationVSIllumination intensity

Solution Approach 1:

The system applies different opacity levels to different regions of the field of view based on local brightness characteristics. Bright regions (such as well-illuminated brain tissue) receive higher opacity to reduce their perceived brightness, while darker regions maintain lower opacity. This spatially varying opacity adjustment resolves the contrast problem for bright objects without unnecessarily dimming darker areas, thereby maintaining overall scene visibility while improving digital information perceivability.

Inventive Principle:
Principle #3Local quality

2Loss of information

If opacity is increased to improve digital information visibility, then contrast with bright objects improves, but surrounding objects and portions lose brightness

Engineering Contradiction:
Improvelegibility of visual overlayVSAvoidbrightness of surrounding objects
Core Design Contradiction:
Loss of informationVSIllumination intensity

Solution Approach 1:

The system calculates opacity values on a per-region basis using brightness maps of the real-world scene. Each region's opacity is independently determined based on its local brightness characteristics, allowing selective dimming only where necessary (bright regions) while preserving brightness in other regions. This localized approach ensures digital information remains legible against bright backgrounds without sacrificing the visibility of surrounding objects.

Inventive Principle:
Principle #3Local quality

3Loss of information

If uniform opacity adjustment is applied to the entire field of view, then digital information becomes visible, but spatial selectivity is lost and overall scene quality deteriorates

Engineering Contradiction:
Improvevisibility of digital overlayVSAvoidquality of visual perception
Core Design Contradiction:
Loss of informationVSEase of operation

Solution Approach 1:

The system divides the field of view into multiple regions and assigns different opacity values to each region based on local brightness analysis. This spatially selective opacity adjustment maintains high visual quality by preserving brightness in dark regions while applying higher opacity only in bright regions where digital information needs enhancement. The result is both improved digital information visibility and maintained overall scene quality.

Inventive Principle:
Principle #3Local quality

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 system effectively increases the contrast between the visual overlay and objects, enhancing the legibility and perceivability of digital information in AR/MR environments, particularly in surgical settings where bright objects are involved, by adjusting illumination or attenuation based on optical properties.

Implementation Method 1

at least one sensor for sensing at least one optical property of the object

Methodology Applied
Scientific EffectLight sensing: Photoelectric Effect

Implementation Method 2

selectively adjust an illumination of one of more portions of the field of view

Methodology Applied
Scientific EffectLight emission: Light Emitting Diode

Implementation Method 3

selectively adjust an optical attenuation of the one of more portions of the field of view

Methodology Applied
Scientific EffectOptical absorption: Absorption (EM radiation)

Data Source

PatentEP3819699B1Optical system and corresponding apparatus, method and computer program
Publication Date: 2024.02.21 LEICA INSTRUMENTS (SINGAPORE) PTE LTD
  • EP3819699B1 patent drawingFigure 1a~1b
  • EP3819699B1 patent drawingFigure 1c~2
  • EP3819699B1 patent drawingFigure 3

AI summary

Examples relate to an optical system and to a corresponding apparatus, method and computer program. The optical system comprises a display module for providing a visual overlay to be overlaid over an object in an augmented reality or mixed reality environment. The optical system comprises at least one sensor for sensing at least one optical property of the object. The optical system comprises a processing module configured to determine the at least one optical property of the object using the at least one sensor. The processing module is configured to determine a visual contrast between the visual overlay to be overlaid over the object and the object, as perceived within a field of view of the augmented reality or mixed reality environment, based on the at least one optical property of the object. The processing module is configured to selectively adjust an illumination of one of more portions of the field of view, or an optical attenuation of the one of more portions of the field of view, based on the determined visual contrast between the visual overlay to be overlaid over the object and the object.