Face Replacement Using Cascade Multichannel CNN for Video Alignment

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Solution Overview

Problem

Current face replacement technologies in video production face challenges due to large appearance variations caused by light conditions, viewing angles, and body poses, and existing face alignment methods degrade in more complex datasets, requiring complex and expensive hardware for 3D-morphable models and not fully utilizing temporal information.

Innovation Solution

A neural network-based face replacement system using a cascade multichannel convolutional neural network (CMC-CNN) for determining facial landmarks, warping the source face to match the target face, and blending using Poisson Image Editing, which selects a facial region of interest and maximizes minimum angles for triangle construction in Delaunay triangulation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If complex and expensive hardware is used to obtain 3D-morphable models for facial motion capture, then facial motion capture accuracy is improved, but device complexity and cost increase

Engineering Contradiction:
Improvefacial motion capture accuracyVSAvoidhardware complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces complex mechanical hardware systems (3D-morphable model capture devices) with a software-based deep learning approach. The CMC-CNN model processes 2D video frames to extract facial landmarks and motion information, eliminating the need for expensive hardware while achieving comparable or superior accuracy through temporal information utilization and multi-channel feature learning

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent creates a digital copy of facial motion through 2D video frame analysis rather than requiring physical 3D scanning hardware. By using the CMC-CNN to regress facial landmarks from 2D images and temporal sequences, the system captures facial motion dynamics without needing complex optical or mechanical capture equipment

Inventive Principle:
Principle #26Copying

2Ease of manufacture

If face editing methods blend source face into target face, then face replacement is achieved, but temporal information in video sequence is not fully utilized

Engineering Contradiction:
Improveface replacement implementationVSAvoidtemporal information utilization
Core Design Contradiction:
Ease of manufactureVSLoss of information

Solution Approach 1:

The patent ensures continuous utilization of temporal information by processing video frames as sequences and applying the CMC-CNN model across multiple time steps. The model maintains temporal coherence by using previous frame predictions and optical flow information, ensuring that facial landmarks and expressions evolve continuously and realistically throughout the video sequence rather than treating each frame independently

Inventive Principle:
Principle #20Continuity of useful action

Solution Approach 2:

The patent implements feedback mechanisms where the model uses predicted facial landmarks from previous frames and temporal difference information to refine current frame predictions. The CMC-CNN architecture incorporates temporal context and uses iterative refinement processes that feed back into the prediction process, ensuring consistent and accurate face replacement across the entire video sequence

Inventive Principle:
Principle #23Feedback

3Measurement precision

If cascade regression-based methods with shape indexed features are used for face alignment, then alignment accuracy is improved, but computational complexity increases

Engineering Contradiction:
Improveface alignment accuracyVSAvoidcomputational complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces traditional cascade regression-based computational systems with a deep learning-based CMC-CNN model. Instead of using multiple stages of hand-crafted feature extraction and regression (such as SIFT features with random ferns or linear regression models), the system uses convolutional neural networks to automatically learn and extract relevant features directly from image data, achieving superior accuracy with more efficient computation

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent transforms the face alignment problem from a multi-stage regression process with fixed hand-crafted parameters to a unified deep learning model with learnable parameters. The CMC-CNN automatically optimizes feature extraction and landmark regression through training on large datasets, eliminating the need for manual feature engineering and cascade stage configurations while achieving higher accuracy and computational efficiency

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentUS10733699B2Face replacement and alignment
Publication Date: 2020.08.04 STRATAVISION AI INC
  • US10733699B2 patent drawing
  • US10733699B2 patent drawing
  • US10733699B2 patent drawing

AI summary

A face replacement system for replacing a target face with a source face can include a facial landmark determination model having a cascade multichannel convolutional neural network (CMC-CNN) to process both the target and the source face. A face warping module is able to warp the source face using determined facial landmarks that match the determined facial landmarks of the target face, and a face selection module is able to select a facial region of interest in the source face. An image blending module is used to blend the target face with the selected source region of interest.