RGBW Image Sensor Noise Reduction via Data Segmentation

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing image pickup elements with RGBW pixels suffer from insufficient reduction of color noise in generated images, particularly when using signal outputs from these pixels.

Innovation Solution

The image pickup apparatus employs a signal processing unit that generates resolution data from one pixel group and color data from another, with up-conversion processing to enhance image resolution and reduce color noise by interpolating signals from surrounding pixels, particularly using a RGBW 12 array configuration where W pixels surround color pixels, thereby improving sensitivity and accuracy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If RGBW pixels are used to increase sensitivity and obtain high S/N ratio images, then image sensitivity and signal-to-noise ratio are improved, but color noise in generated images is insufficiently reduced

Engineering Contradiction:
Improvesignal-to-noise ratioVSAvoidcolor noise
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent segments the pixel array into distinct functional groups: first pixel groups (RGB pixels) dedicated to generating resolution data and second pixel groups (W pixels) dedicated to generating color data. This segmentation allows each pixel type to optimize its specific function, with RGB pixels providing spatial resolution information and W pixels providing accurate color information, thereby reducing color noise while maintaining high sensitivity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces an intermediary processing stage that separates resolution data and color data into distinct processing streams. Resolution data from RGB pixels and color data from W pixels are processed independently through different computational paths before being combined, allowing optimized noise reduction algorithms to operate on each data type separately and effectively reduce color noise.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If up-conversion processing is performed to enhance image resolution, then image resolution is improved, but processing complexity increases

Engineering Contradiction:
Improveimage resolutionVSAvoidprocessing complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent performs preliminary separation of resolution data and color data at the pixel readout stage, organizing them into distinct data streams before processing. This preliminary organization simplifies subsequent up-conversion processing by providing structured input data, reducing the computational complexity compared to processing mixed pixel data.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent applies up-conversion processing that increases the dimensional resolution of the image data. By processing resolution data and color data through different computational dimensions and then combining them, the system achieves enhanced image resolution while managing processing complexity through structured multi-dimensional processing.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

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 effectively reduces color noise and maintains high image resolution, while also ensuring compatibility with existing image processing units, thereby generating images with improved signal-to-noise ratio and reduced false colors.

Implementation Method 1

each of the photoelectric conversion units included in the first pixel group and each of the photoelectric conversion units included in the second pixel group have mutually different wavelength bands of lights to be photoelectrically converted

Methodology Applied
Scientific EffectPhotoelectric conversion: Photoelectric Effect

Data Source

PatentUS10229475B2Apparatus, system, and signal processing method for image pickup using resolution data and color data
Publication Date: 2019.03.12 CANON KK
  • US10229475B2 patent drawing
  • US10229475B2 patent drawing
  • US10229475B2 patent drawing

AI summary

Resolution data is generated by using signals output by a first pixel group. Color data is generated by using signals output by a second pixel group. The resolution data is combined with the color data to generate first data. Up-conversion processing is performed on the first data to generate second data, and mosaic processing is performed on the second data to generate data of a predetermined array.