Machine Learning Colorization of Line Drawings via Element-Specific Estimation Models

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Solution Overview

Problem

Conventional automatic colorization technologies are unable to accurately colorize line drawings of characters and elements in games and animations.

Innovation Solution

An image processing method that uses machine learning to generate an estimation model from pairs of line-drawing and colorized images, allowing for accurate colorization of line drawings by identifying elements and modifying colorization layers based on user input, while storing learning data for iterative improvement.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional automatic colorization technologies are used, then the process is simple and fast, but the colorization accuracy of line drawings in games and animations is poor

Engineering Contradiction:
Improvecolorization accuracyVSAvoidsystem complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The system segments the colorization task by creating separate estimation models for different elements (characters, backgrounds, objects). Each model is trained on element-specific learning data, allowing accurate colorization of line drawings while maintaining manageable system complexity through modular architecture

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system performs preliminary actions by pre-training estimation models using extensive learning data pairs of line drawings and colorized images. These pre-trained models are stored and can be directly applied to new line drawings, achieving high accuracy without requiring complex real-time processing

Inventive Principle:
Principle #10Preliminary action

2Measurement precision

If element-specific estimation models are generated through machine learning, then colorization accuracy improves, but processing time and computational resources increase

Engineering Contradiction:
Improvecolorization accuracyVSAvoidmodel generation time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The system performs model training in advance using accumulated learning data, generating element-specific estimation models before they are needed. These pre-trained models are stored for reuse, eliminating the need to retrain models for each colorization task and reducing processing time while maintaining high accuracy

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system creates and stores copies of trained estimation models for different elements. Once a model is trained on learning data, the model copy can be reused multiple times for colorizing similar elements, significantly reducing the time and computational resources required for actual colorization operations

Inventive Principle:
Principle #26Copying

3Measurement precision

If learning data is stored and reused for model generation, then colorization quality improves, but data management complexity increases

Engineering Contradiction:
Improvecolorization qualityVSAvoiddata management complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The system segments learning data by element type (characters, backgrounds, objects), organizing data into element-specific datasets. This segmentation allows the system to manage complex data through modular organization, where each element's learning data is handled independently by its corresponding estimation model

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system implements feedback mechanisms where colorization results are evaluated and used to generate additional learning data. This feedback loop continuously improves model accuracy by incorporating real-world performance data, managing complexity through automated feedback processing rather than manual data curation

Inventive Principle:
Principle #23Feedback

Data Source

PatentUS11880912B2Image processing method, image processing system, and program for colorizing line-drawing images using machine learning
Publication Date: 2024.01.23 CYGAMES INC
  • US11880912B2 patent drawing
  • US11880912B2 patent drawing
  • US11880912B2 patent drawing

AI summary

Provided is an image processing method wherein a computer: generates an estimation model for estimating the colorized image from the line-drawing image for each element through machine learning using the learning data of that element; identifies the element corresponding to the subject line-drawing image; generates the colorized image that is to be paired with the subject line-drawing image, on the basis of the estimation model corresponding to the identified element and the subject line-drawing image; generates a colorization layer of an image file including a line-drawing layer and the colorization layer by using the subject colorized image; extracts the modified colorization layer and the corresponding line-drawing layer as the image pair for learning; and stores a pair of the line-drawing image of the extracted line-drawing layer and the colorized image of the extracted colorization layer, as the learning data, in association with the element corresponding to the estimation model.