Image Processing Unit Dynamic Threshold Noise Correction

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing image processing methods struggle to accurately determine suitability for image synthesis due to the use of fixed thresholds, leading to errors in noise correction and ghosting in images with varying light and dark portions, resulting in suboptimal image quality.

Innovation Solution

An image processing unit that dynamically sets thresholds based on pixel outputs of reference images, using a threshold table correlating mean pixel values to determine suitable image blocks for synthesis, thereby avoiding fixed threshold limitations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a fixed threshold is used to determine image synthesis suitability, then the determination process is simple and fast, but image synthesis accuracy deteriorates in regions with varying light conditions

Engineering Contradiction:
Improveimage synthesis processing speedVSAvoidimage synthesis determination accuracy
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The patent applies dynamics by transitioning from a fixed threshold to a variable threshold that adapts to local image characteristics. The threshold is dynamically adjusted based on the mean pixel output values of image blocks, allowing the determination criteria to change according to lighting conditions in different regions of the image.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the parameter of the threshold value based on the mean pixel output of each image block. By calculating the mean pixel output and using it to determine an appropriate threshold, the system adjusts the synthesis determination parameter to match the local lighting conditions, resolving the contradiction between processing speed and accuracy.

Inventive Principle:
Principle #35Parameter changes

2Manufacturing precision

If a large threshold is set to correct noise in light portions, then noise correction accuracy improves, but motion detection capability in dark portions deteriorates

Engineering Contradiction:
Improvenoise correction accuracy in light portionsVSAvoidmotion detection accuracy in dark portions
Core Design Contradiction:
Manufacturing precisionVSMeasurement precision

Solution Approach 1:

The patent applies local quality by treating different regions of the image differently based on their lighting conditions. Each image block is evaluated independently, and the threshold is adjusted according to the mean pixel output of that specific block. This allows optimal threshold selection for both light portions (to correct noise) and dark portions (to detect motion), without compromising either region.

Inventive Principle:
Principle #3Local quality

3Object-generated harmful factors

If image blocks with large RGB difference values are excluded from synthesis, then ghosting is reduced, but noise correction effectiveness deteriorates

Engineering Contradiction:
Improveghosting reductionVSAvoidnoise correction effectiveness
Core Design Contradiction:
Object-generated harmful factorsVSManufacturing precision

Solution Approach 1:

The patent changes the threshold parameter dynamically based on the mean pixel output of each image block. In dark regions where motion is more likely, a lower threshold allows synthesis to proceed even with smaller RGB differences, preventing ghosting. In light regions, a higher threshold maintains noise correction effectiveness. This dynamic parameter adjustment resolves the contradiction between ghosting reduction and noise correction.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentUS8983140B2Image processing unit, image processing method, and image processing program to correct blurs and noise in an image
Publication Date: 2015.03.17 RICOH CO LTD
  • US8983140B2 patent drawing
  • US8983140B2 patent drawing
  • US8983140B2 patent drawing

AI summary

An image processing unit includes a memory unit in which continuously captured images including a reference image and a comparative image are stored, an image dividing unit to divide the reference image and the comparative image into image blocks of a predetermined size, a mean value calculator unit to calculate a mean value of pixel outputs in each image block of each of the reference and comparative images, a threshold determining unit to determine a threshold according to a mean value of pixel outputs of an image block of the reference image, and a determiner unit to compare the threshold with a difference value of the mean values of the pixel outputs in the image blocks of the reference and comparative images to be synthesized and determine whether the image blocks of the reference and comparative images are suitable for image synthesis based on a result of the comparison.