Automatic Line Drawing Coloring via Two-Step Model Inference

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Solution Overview

Problem

Conventional software struggles to automatically color line drawing images effectively, as these images lack luminance information and often have open regions, making it difficult for existing colorization technologies to accurately process and color them.

Innovation Solution

An automatic line drawing coloring method and apparatus that utilize a two-step coloring process, where line drawing data is first reduced in size and then colored using pre-learned models, allowing for the integration of hint information and enabling user selection of models for varied coloring tendencies, and a graphical user interface for displaying and interacting with the coloring process.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If conventional software is used for coloring, then closed regions can be colored, but line drawing images with open regions cannot be easily colored

Engineering Contradiction:
Improvecoloring capabilityVSAvoidcoloring accuracy
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The system performs preliminary actions by reducing the line drawing image to a smaller size before coloring, and by pre-learning coloring models from sample data. This preparation enables the coloring algorithm to handle open regions effectively, as the reduced image allows better processing of boundary information and region identification.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The invention changes the parameter of image size by reducing the line drawing image to a predetermined smaller size before coloring. This parameter change enables the coloring algorithm to process open regions more effectively, as the reduced resolution allows better detection and coloring of regions without requiring perfectly closed boundaries.

Inventive Principle:
Principle #35Parameter changes

2Productivity

If black-and-white photographs are colorized using luminance information, then coloring can be achieved, but line drawing images without luminance information are more difficult to process

Engineering Contradiction:
Improvecoloring speedVSAvoidprocessing difficulty
Core Design Contradiction:
ProductivityVSDifficulty of detecting and measuring

Solution Approach 1:

The system introduces an intermediary approach by using pre-learned coloring models that were trained on sample line drawing images. These models serve as mediators that capture the relationship between line drawing structures and appropriate colors, enabling the system to colorize images without requiring luminance information or complex real-time analysis.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The coloring models are prepared in advance through pre-learning from sample data. This preliminary action stores the knowledge of how to translate line drawing structures into colors, allowing rapid coloring of new images without needing to perform complex analysis during the actual coloring process.

Inventive Principle:
Principle #10Preliminary action

3Manufacturing precision

If large-sized line drawing images are processed directly, then original quality is maintained, but processing time and computational load increase

Engineering Contradiction:
Improveimage qualityVSAvoidprocessing time
Core Design Contradiction:
Manufacturing precisionVSLoss of time

Solution Approach 1:

The system segments the coloring process into two stages: first reducing the image to a smaller size for preliminary coloring processing, then using the colored reduced image to guide the final coloring of the original image. This segmentation allows the computationally intensive coloring algorithm to work on a smaller image initially, reducing overall processing time while maintaining quality.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system performs preliminary reduction of the image to a predetermined smaller size before coloring. This preliminary action reduces the computational load for the coloring algorithm, as it processes a smaller image first. The colored reduced image then serves as a guide for coloring the original large image, maintaining quality while reducing processing time.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentUS11915344B2Method and apparatus for automatic line drawing coloring and graphical user interface thereof
Publication Date: 2024.02.27 PREFERRED NETWORKS INC
  • US11915344B2 patent drawing
  • US11915344B2 patent drawing
  • US11915344B2 patent drawing

AI summary

An apparatus and a method for coloring line drawing is disclosed for: acquiring line drawing data; performing reduction processing on the line drawing data to be a predetermined reduced size to obtain reduced line drawing data; coloring the reduced line drawing data based on a first learned model which is learned in advance using sample data; and coloring original line drawing data with the colored reduced data and the original line drawing data as inputs based on a second learned model which is learned in advance.