Dual-Pixel Depth Mapping for Single-Exposure Background Blur

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Solution Overview

Problem

Existing image capture devices struggle to selectively blur background portions of images while keeping foreground objects in focus, especially when dedicated depth sensors are unavailable, and traditional depth estimation methods from dual pixel images are challenging due to limited cues and correspondence issues.

Innovation Solution

A machine learning approach using neural networks is employed to estimate depth maps from dual pixel images, leveraging parallax, semantic, and defocus cues, trained on a large dataset from a multi-camera device, to generate accurate depth maps that guide selective blurring of background objects.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If conventional structured light methods are used for depth mapping, then depth information can be obtained, but the process is time-consuming and requires sequential projection of multiple patterns

Engineering Contradiction:
Improvedepth mapping speedVSAvoidtime for projecting multiple patterns
Core Design Contradiction:
ProductivityVSLoss of time

Solution Approach 1:

The patent segments the depth information capture into two simultaneous channels: one for texture capture and another for depth capture using dual pixel technology. This allows parallel processing of different image types without sequential pattern projection, resolving the time loss issue while maintaining depth mapping capability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent performs preliminary action by capturing both texture and depth information in a single exposure using dual pixel imaging. The depth information is pre-captured alongside texture data, eliminating the need for subsequent sequential pattern projections and enabling real-time depth mapping.

Inventive Principle:
Principle #10Preliminary action

2Measurement precision

If multiple image captures are performed for depth estimation, then depth accuracy can be improved, but the frame rate decreases

Engineering Contradiction:
Improvedepth estimation accuracyVSAvoidframe rate
Core Design Contradiction:
Measurement precisionVSSpeed

Solution Approach 1:

The patent merges texture capture and depth capture into a single imaging operation using dual pixel technology. Both types of information are captured simultaneously in one exposure, maintaining frame rate while obtaining sufficient data for depth estimation through unified multi-task processing.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent performs preliminary action by capturing all necessary depth and texture information in a single exposure. This preliminary capture eliminates the need for multiple sequential captures, maintaining high frame rate while providing sufficient data for accurate depth estimation through advanced processing algorithms.

Inventive Principle:
Principle #10Preliminary action

3Reliability

If depth information is captured using traditional methods, then depth mapping can be achieved, but real-time processing is difficult due to computational complexity

Engineering Contradiction:
Improvedepth mapping capabilityVSAvoidcomputational processing complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent replaces complex mechanical structured light projection systems with a computational approach using dual pixel imaging. Depth information is obtained through image processing of simultaneously captured photos, substituting physical pattern projection with algorithmic depth extraction, thereby reducing device complexity while maintaining depth mapping reliability.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the parameter of information capture from sequential multi-pattern projection to simultaneous dual-channel imaging. By capturing both texture and depth information in a single exposure, the computational complexity is reduced while maintaining depth mapping capability through efficient processing of unified data.

Inventive Principle:
Principle #35Parameter changes

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

This method enables natural and pleasing depth-dependent blurring of background objects while maintaining foreground clarity, even on mobile devices, without requiring network connectivity, and produces higher-quality selectively blurred images than traditional techniques.

Implementation Method 1

a lens is arranged to receive light from the object and project the light onto a sensor array

Methodology Applied
Scientific EffectLight: Light

Implementation Method 2

the sensor array comprises a plurality of photosensitive elements arranged in a grid pattern

Methodology Applied
Scientific EffectPhotoelectric Effect: Photoelectric Effect

Data Source

PatentEP3891703B1Depth prediction from dual pixel images
Publication Date: 2026.04.29 GOOGLE LLC
  • EP3891703B1 patent drawingFigure 1
  • EP3891703B1 patent drawingFigure 2
  • EP3891703B1 patent drawingFigure 3

AI summary

Apparatus and methods related to using machine learning to determine depth maps for dual pixel images of objects are provided. A computing device can receive a dual pixel image of at least a foreground object. The dual pixel image can include a plurality of dual pixels. A dual pixel of the plurality of dual pixels can include a left-side pixel and a right-side pixel that both represent light incident on a single dual pixel element used to capture the dual pixel image. The computing device can be used to train a machine learning system to determine a depth map associated with the dual pixel image. The computing device can provide the trained machine learning system.