Spatial Frequency Analysis for Draft Printing Contrast

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Solution Overview

Problem

Draft printing processes often consume excessive ink and toner to ensure all features are visible, leading to wasteful usage and increased environmental impact, as they typically apply uniform reduction in marking material without considering spatial frequency variations.

Innovation Solution

The method evaluates spatial frequencies in different regions of a printable item to calculate tailored marking material reduction values based on human contrast recognition patterns, allowing for variable toner usage that optimizes visibility while minimizing material consumption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of information

If uniform marking material reduction is applied to ensure all features are visible, then visibility of all printed items is improved, but marking material consumption increases

Engineering Contradiction:

Improvevisibility of printed featuresVSAvoidmarking material consumption

Core Design Contradiction:

Loss of informationVSLoss of substance

Solution Approach 1:

The patent applies different marking material reduction values to different spatial frequency regions of the printable item. High spatial frequency regions (fine details, text) receive lower reduction values to maintain visibility, while low spatial frequency regions (backgrounds, large areas) receive higher reduction values to reduce material consumption. This local differentiation resolves the contradiction by optimizing both visibility and material usage in different areas simultaneously.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent changes the marking material reduction parameter based on spatial frequency analysis of different regions. By calculating spatial frequencies and applying non-linear contrast recognition patterns, the system dynamically adjusts reduction values for each region, transforming a uniform parameter approach into a variable parameter approach that resolves the visibility-material consumption trade-off.

Inventive Principle:

Principle #35Parameter changes

2Loss of information

If higher contrast levels are used to ensure all printed items are visible, then readability is improved, but ink and toner usage increases

Engineering Contradiction:

Improvereadability of printed featuresVSAvoidink and toner usage

Core Design Contradiction:

Loss of informationVSQuantity of substance

Solution Approach 1:

The patent applies contrast level adjustments locally based on spatial frequency regions. High spatial frequency regions maintain higher contrast levels for readability, while low spatial frequency regions use lower contrast levels to reduce material usage. This resolves the contradiction by applying different contrast strategies where appropriate.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent dynamically changes contrast level parameters based on spatial frequency analysis and human contrast recognition patterns. The non-linear relationship between spatial frequency and perceived contrast allows the system to optimize readability while minimizing material consumption across different regions.

Inventive Principle:

Principle #35Parameter changes

3Reliability

If uniform quality printing is applied to all regions, then all features are clearly visible, but environmental impact and operating costs increase

Engineering Contradiction:

Improvequality of printed outputVSAvoidenvironmental impact and operating costs

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent applies different quality levels to different spatial frequency regions based on their visibility requirements. High spatial frequency regions (critical for readability) receive higher quality treatment, while low spatial frequency regions receive reduced quality treatment. This resolves the contradiction by maintaining necessary quality where needed while reducing environmental impact elsewhere.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent changes printing quality parameters dynamically based on spatial frequency analysis and human perception characteristics. By leveraging the non-linear relationship between spatial frequency and perceived contrast, the system optimizes the balance between output quality and environmental/operational costs.

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS8467105B2Optimal contrast level draft-mode printing using spatial frequency analysis

Publication Date: 2013.06.18 XEROX CORP

AI summary

Devices and methods herein receive a command into a computerized device to perform a printing draft operation of a printable item using a reduced amount of marking material (a reduced amount of ink, toner, etc.). The methods herein evaluate at least two different regions of the printable item to determine spatial frequencies of the different regions, and calculate at least two marking material reduction values for the different regions of the printable item based on the spatial frequencies of the different regions. Then, the methods herein apply the marking material reduction values to the printable item to produce a file containing reduced marking material printing commands for a printing device to print the printable item.