Print Control Apparatus Sketch Image Conversion for Toner Reduction

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Solution Overview

Problem

Existing draft-printing methods reduce image quality and inefficiently use toner, as they are based on density reduction and struggle with converting whole images into sketch images, especially with vector-based composite graphics and rasterized images, leading to ineffective toner-saving rules and poor visual quality.

Innovation Solution

A method that extracts graphical primitives from print data, groups them based on geometrical vicinity, and converts them into a sketch image format, allowing for improved visibility and toner savings by modifying print data to include a sketch image representation, which can be used for draft-printing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of substance

If draft-printing is performed using density reduction, then toner usage is reduced, but image quality deteriorates

Engineering Contradiction:
Improvetoner usageVSAvoidimage quality
Core Design Contradiction:
Loss of substanceVSManufacturing precision

Solution Approach 1:

The image is segmented into edge components and non-edge components. Edge components are printed with high density to maintain visibility, while non-edge components are printed with reduced density to save toner. This segmentation allows selective application of toner-saving rules without compromising overall image quality.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different printing densities are applied to different regions of the image based on their importance. Edge regions receive high-density printing to preserve structural information, while non-edge regions receive low-density printing for toner savings. This local quality differentiation resolves the contradiction between image quality and toner efficiency.

Inventive Principle:
Principle #3Local quality

2Manufacturing precision

If vector-based composite graphics are converted into sketch images, then draft-printing visibility is improved, but processing complexity increases

Engineering Contradiction:
Improvedraft-printing visibilityVSAvoidprocessing complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

Vector-based composite graphics are segmented into individual graphical primitives before conversion to sketch images. This segmentation simplifies the conversion process by handling each primitive separately, reducing processing complexity while maintaining the ability to generate high-quality sketch representations for improved draft-printing visibility.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Graphical primitives are pre-processed and organized into groups based on their spatial relationships before sketch image conversion. This preliminary action simplifies subsequent processing steps and reduces overall computational complexity while enabling effective draft-printing visualization.

Inventive Principle:
Principle #10Preliminary action

3Productivity

If graphical primitives are processed independently, then processing efficiency is improved, but image integrity is lost

Engineering Contradiction:
Improveprocessing efficiencyVSAvoidimage integrity
Core Design Contradiction:
ProductivityVSStability of the object's composition

Solution Approach 1:

Graphical primitives are processed independently for efficiency, then merged into groups based on spatial proximity and visual relationships. This merging preserves image integrity by maintaining the holistic structure while benefiting from the efficiency of independent primitive processing.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The image processing is segmented into two phases: independent primitive processing for efficiency, followed by grouping for integrity. This segmentation allows both processing efficiency and image integrity to be achieved at different stages of the workflow.

Inventive Principle:
Principle #1Segmentation

4Ease of manufacture

If rasterized images are used for draft-printing, then processing simplicity is improved, but toner efficiency deteriorates

Engineering Contradiction:
Improveprocessing simplicityVSAvoidtoner efficiency
Core Design Contradiction:
Ease of manufactureVSLoss of substance

Solution Approach 1:

Rasterized images are segmented into edge and non-edge components, allowing selective application of toner-saving rules. This segmentation maintains the processing simplicity of rasterization while improving toner efficiency by reducing toner usage in non-edge regions.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different toner densities are applied to different regions of the rasterized image based on local characteristics. Edge regions maintain high density for visibility, while non-edge regions use reduced density for toner savings, resolving the contradiction between processing simplicity and toner efficiency.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP2574033B1Print controlling apparatus, image forming apparatus, and method for forming image
Publication Date: 2020.08.12 HEWLETT PACKARD DEVELOPMENT COMPANY LP
  • EP2574033B1 patent drawingFigure 1(a)~1(b)
  • EP2574033B1 patent drawingFigure 2
  • EP2574033B1 patent drawingFigure 3

AI summary

An image forming apparatus, a print controlling apparatus, and an image forming method using the same are provided. The image forming method includes extracting at least one graphical primitive from print data, forming an image by arranging the graphical primitive according to whether the extracted graphical primitives are close to each other or not, converting the formed image into a sketch image, modifying the print data by replacing the sketch image and some of the graphical primitives constituting the sketch image, and draft-printing using the modified print data.