Camera Module With Sequential Spectral Filtering for Moiré Reduction

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Solution Overview

Problem

Current imaging systems using Bayer sensors suffer from reduced image resolution and issues such as moiré patterns, color noise, and zippering noise due to interpolation processes, degrading imaging quality.

Innovation Solution

An imaging system with a filter module that selectively outputs optical signals of different bands to the same pixel at different times, combined with a processing module that performs color restoration and gamma correction, eliminating the need for demosaicing and enhancing color accuracy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a Bayer sensor with demosaicing algorithm is used to obtain full-color images, then color imaging capability is achieved, but image resolution is reduced and imaging quality is degraded

Engineering Contradiction:
Improvecolor imaging capabilityVSAvoidimage resolution
Core Design Contradiction:
Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

The patent segments the color filtering function across multiple spectral bands by using a tunable spectral filter that can be adjusted to different wavelength ranges. Instead of having each pixel capture only one color component simultaneously, the system captures spectral information sequentially across multiple bands, then segments the reconstruction task into independent optimization problems for each spectral component, finally integrating them to form the complete color image.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent employs a dynamic tunable spectral filter that can change its transmission characteristics in real-time. The filter's spectral response is dynamically adjusted to capture different wavelength bands sequentially, allowing the same optical path to adaptively serve multiple spectral sampling functions, thereby eliminating the need for fixed color filter arrays and improving spatial resolution.

Inventive Principle:
Principle #15Dynamics

2Adaptability or versatility

If interpolation is performed to obtain full-color images from Bayer sensor data, then color information is completed, but problems such as moiré pattern, color noise, and zippering noise occur

Engineering Contradiction:
Improvecolor information completenessVSAvoidmoiré pattern, color noise, and zippering noise
Core Design Contradiction:
Adaptability or versatilityVSObject-generated harmful factors

Solution Approach 1:

The patent performs preliminary spectral sampling by capturing images at multiple predetermined spectral bands before final image reconstruction. By pre-capturing spectral information at optimized wavelength points, the system prepares sufficient data for accurate color reconstruction without requiring heavy interpolation, thereby preventing the generation of moiré patterns and color noise artifacts.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent implements an iterative reconstruction algorithm that uses feedback from the captured spectral data to optimize the estimation of missing color information. The system continuously refines the color image by comparing predicted spectral responses with actual measurements, adjusting the reconstruction parameters to minimize artifacts such as zippering noise and color noise while maintaining color accuracy.

Inventive Principle:
Principle #23Feedback

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 increases image resolution, avoids moiré patterns, and improves color restoration accuracy by providing finer spectral data and multi-degree of freedom in color tuning.

Implementation Method 1

a filter module configured to: receive a control signal output by the filter control unit, and output optical signals of different bands in incident light to a same pixel on the sensor module at different times under control of the control signal

Methodology Applied
Scientific EffectSpectral filtering: Filter (optical)

Data Source

PatentEP4075781B1Camera module, imaging method, and imaging apparatus
Publication Date: 2025.07.30 HUAWEI TECH CO LTD
  • EP4075781B1 patent drawingFigure 1
  • EP4075781B1 patent drawingFigure 2
  • EP4075781B1 patent drawingFigure 3

AI summary

This application provides a camera module, an imaging method, and an imaging apparatus. The camera module in this application includes a filter module and a sensor module. The filter module is configured to output target optical signals of different bands in optical signals incident on the filter module to a same pixel on the sensor module at different times. The sensor module is configured to: convert the target optical signals incident on the sensor module into electrical signals, and output the electrical signals. This application provides the camera module, the imaging method, and the imaging apparatus, to improve imaging quality of an image.