Toner Saving Rendering Unit for White Character Visibility

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Solution Overview

Problem

Toner saving processing methods often degrade the visibility of white characters when they are inside objects from which colors are removed, leading to reduced image quality.

Innovation Solution

An image processing system that includes a toner saving rendering unit capable of discriminating between graphics and character objects, determining if a character is white, and adjusting its color or the surrounding region's density to maintain visibility, while performing toner saving processing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of substance

If color removal processing is applied to inner regions surrounded by edges during toner saving processing, then toner consumption is reduced, but visibility of white characters inside the inner region is degraded

Engineering Contradiction:
Improvetoner consumptionVSAvoidvisibility of white characters
Core Design Contradiction:
Loss of substanceVSReliability

Solution Approach 1:

The patent applies different processing treatments to different regions within the inner area surrounded by edges. Specifically, white character regions are identified and preserved with original coloring, while non-character regions undergo color removal or density reduction. This local differentiation allows toner saving in background areas while maintaining character visibility.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The processing method segments the inner region into character portions and non-character portions. By detecting edges and analyzing regional characteristics, the system divides the area inside edges into segments that require different handling - white characters are segmented and protected from color removal, while other areas are processed for toner saving.

Inventive Principle:
Principle #1Segmentation

2Loss of substance

If density is decreased throughout the inner region for toner saving, then printing cost is reduced, but image quality and legibility of text elements are compromised

Engineering Contradiction:
Improveprinting costVSAvoidimage quality
Core Design Contradiction:
Loss of substanceVSManufacturing precision

Solution Approach 1:

The patent implements local quality control by applying different density adjustment strategies to different areas. White character regions maintain their original density and color characteristics, while non-character background regions have their density reduced. This selective approach preserves image quality where needed while achieving toner savings in appropriate areas.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The system performs preliminary detection and classification of regions before applying toner saving processing. By first identifying edges, then analyzing inner regions for character content, and finally determining which areas should preserve vs. reduce density, the method prepares the image data in advance to guide subsequent selective processing that maintains quality while saving toner.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP2852144B1Image processing apparatus, image processing method and computer-readable storage medium
Publication Date: 2020.04.15 CANON KK
  • EP2852144B1 patent drawingFigure 1
  • EP2852144B1 patent drawingFigure 2
  • EP2852144B1 patent drawingFigure 3

AI summary

An image processing apparatus including an extraction unit (S502) configured to extract a graphics object from image data; and a conversion unit (404) configured, in a case where recording material saving processing is instructed (S501) and a character whose density is equal to or less than a predetermined density is included inside a graphics object extracted by the extraction unit (S504, S505), to convert the character so as to increase the density thereof (S506) and to convert a region other than the character inside the graphics object so as to decrease the density thereof (S507).