Image Sensor Phase Pixels Depth Map Generation

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Solution Overview

Problem

Existing methods for obtaining depth maps are complex and costly, or unsuitable for capturing moving objects, as they often require multiple photographs or specialized equipment like dual cameras or time-of-flight systems.

Innovation Solution

An image processing method using an image sensor with evenly distributed photosensitive elements, including phase pixels, to calculate phase differences across area windows of an input image, allowing for the determination of a depth map without additional images or auxiliary devices.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a dual camera system is used to obtain depth map, then depth information can be obtained, but the cost and device complexity increase significantly

Engineering Contradiction:
Improvedepth information accuracyVSAvoiddual camera system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The image sensor is segmented into different pixel types (phase detection pixels and imaging pixels) within a single sensor array. Phase detection pixels are specifically arranged to detect phase differences of autocollimated light, while imaging pixels capture standard images. This segmentation allows depth information extraction without requiring multiple cameras.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The single image sensor performs multiple functions: it captures imaging data through imaging pixels and depth information through phase detection pixels simultaneously. This multi-functionality eliminates the need for separate depth sensing devices while maintaining both imaging and depth measurement capabilities.

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

2Measurement precision

If multiple photographs with different focus are taken by using a common camera, then depth map can be generated, but the method is not suitable for photographing moving objects due to time delays

Engineering Contradiction:
Improvedepth map accuracyVSAvoidtime delay between photographs
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The phase detection pixels continuously detect phase differences of autocollimated light from objects in real-time during a single exposure. This continuous detection eliminates time delays between multiple photographs, making the system suitable for capturing moving objects while maintaining depth measurement accuracy.

Inventive Principle:
Principle #20Continuity of useful action

3Measurement precision

If time of flight system with independent light-emitting unit is used, then depth map can be obtained, but additional auxiliary devices and system complexity are required

Engineering Contradiction:
Improvedepth information accuracyVSAvoidsystem configuration complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent extracts the depth detection function from separate auxiliary devices and integrates it directly into the image sensor through phase detection pixels. These pixels detect phase differences of autocollimated light reflected from objects, eliminating the need for independent light-emitting units and other auxiliary depth sensing devices.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The image sensor serves itself by incorporating phase detection pixels that automatically detect depth information from autocollimated light. The sensor does not require external depth sensing devices or complex auxiliary systems, as it performs both imaging and depth measurement functions independently.

Inventive Principle:
Principle #25Self-service

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 approach simplifies the process of obtaining depth maps, enhances resolution, and is suitable for capturing moving objects by dividing the image into area windows to calculate phase differences, resulting in a more precise and cost-effective depth map generation.

Implementation Method 1

obtain an input image including a plurality of common pixels and a plurality of phase pixel pairs, each of the plurality of phase pixel pairs including a first phase pixel and a second phase pixel

Methodology Applied
Scientific EffectPhase detection:

Implementation Method 2

calculate phase differences between the first phase pixel and the second phase pixel in each of the plurality of phase pixel pairs

Methodology Applied
Scientific EffectAutocollimation:

Implementation Method 3

an image sensor with evenly distributed photosensitive elements, including phase pixels

Methodology Applied
Scientific EffectPhotoelectric effect: Photoelectric Effect

Data Source

PatentEP3389256B1Method and device for processing image
Publication Date: 2023.04.12 HUAWEI TECH CO LTD
  • EP3389256B1 patent drawingFigure 1~2
  • EP3389256B1 patent drawingFigure 3
  • EP3389256B1 patent drawingFigure 4

AI summary

Embodiments of the present invention provide an image processing method and device. The method includes: obtaining an input image, where the input image includes multiple common pixels and multiple phase pixel pairs, and each of the multiple phase pixel pairs includes a first phase pixel and a second phase pixel; dividing the input image into at least two area windows, where each of the at least two area windows includes at least two adjacent phase pixel pairs of the multiple phase pixel pairs; determining, according to the at least two phase pixel pairs in each of the at least two area windows, a phase difference corresponding to each area window; and determining, according to the phase difference corresponding to each area window, a depth map corresponding to the input image. In the foregoing technical solution, the depth map is obtained without photographing multiple input images or using any other auxiliary device.