Camera Module Noise Reduction via Ambient-Flash Exposure Segmentation

Solution Overview

Problem

Conventional digital image processing techniques for capturing higher sensitivity exposures result in increased image noise, degrading image quality and eliminating desirable texture and fine details, while being computationally intensive for mobile devices.

Innovation Solution

A system and method that captures both ambient and flash images using different exposure parameters, with noise reduction techniques applied to generate a de-noised pixel by combining ambient and flash pixels, reducing overall noise in the merged image.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If higher analog gain is used to achieve higher sensitivity exposures, then sensitivity is improved, but image noise increases

Engineering Contradiction:

ImprovesensitivityVSAvoidimage noise

Core Design Contradiction:

Illumination intensityVSObject-generated harmful factors

Solution Approach 1:

The image capture process is segmented into multiple exposures (ambient exposure and flash exposure) taken at different gain levels. The ambient image is captured with higher gain for sensitivity, while the flash image is captured with lower gain for lower noise. These segmented exposures are then combined to achieve both high sensitivity and low noise in the final image.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent changes the gain parameter differently for different exposure sequences. The ambient exposure uses high analog gain to achieve high sensitivity in low-light conditions, while the flash exposure uses low analog gain to minimize noise. By varying the gain parameter across different exposure sequences and combining the results, the patent resolves the contradiction between sensitivity and noise.

Inventive Principle:

Principle #35Parameter changes

2Object-generated harmful factors

If conventional digital image processing techniques are used to reduce noise, then noise is reduced, but desirable texture and fine details are eliminated

Engineering Contradiction:

Improveimage noiseVSAvoidtexture and fine details

Core Design Contradiction:

Object-generated harmful factorsVSLoss of information

Solution Approach 1:

The patent performs noise reduction through a preliminary action of capturing a separate flash exposure at low gain before combining it with the ambient exposure. This preliminary flash capture provides a low-noise reference that is blended with the ambient image, reducing noise while preserving texture and fine details that would otherwise be lost in post-processing de-noising.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The flash exposure acts as an intermediary between the noisy ambient exposure and the final de-noised image. By introducing this intermediate flash image captured at low gain, the patent provides a noise-reduced reference that mediates the combination process, allowing noise reduction while preserving important scene details through weighted blending.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Object-generated harmful factors

If conventional noise reduction techniques are applied, then noise is reduced, but computational complexity increases

Engineering Contradiction:

Improveimage noiseVSAvoidcomputational complexity

Core Design Contradiction:

Object-generated harmful factorsVSDevice complexity

Solution Approach 1:

The patent performs noise reduction through a preliminary action of capturing a separate flash exposure at low gain before combining it with the ambient exposure. This preliminary flash capture provides a low-noise reference that is blended with the ambient image, reducing noise while preserving texture and fine details that would otherwise be lost in post-processing de-noising.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The flash exposure acts as an intermediary between the noisy ambient exposure and the final de-noised image. By introducing this intermediate flash image captured at low gain, the patent provides a noise-reduced reference that mediates the combination process, allowing noise reduction while preserving important scene details through weighted blending.

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentUS11375085B2Systems and methods for capturing digital images

Publication Date: 2022.06.28 DUELIGHT LLC

AI summary

A system, method, and computer program product are provided for capturing digital images. In use, an ambient image comprising a plurality of ambient pixels and a flash image comprising a plurality of flash pixels is captured, via a camera module. Next, at least one de-noised pixel based on the ambient image is generated. Additionally, a resulting image is generated by combining the at least one de-noised pixel and a corresponding flash pixel. Additional systems, methods, and computer program products are also presented.