3D Shape Estimation for Cross-Camera Subject Identification

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing systems face challenges in accurately identifying the same person across different cameras due to variations in installation position and viewing angle, leading to differences in feature quantity vectors.

Innovation Solution

An image processing apparatus that extracts subject images from multiple cameras, estimates the three-dimensional shape and state of subjects, generates predictive images based on these estimates, and determines subject identity by comparing predictive images with actual images from other cameras.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If feature quantity vectors are extracted from images captured by different cameras, then person identification can be performed, but identification accuracy deteriorates due to variations in installation position and viewing angle

Engineering Contradiction:
Improveidentification accuracyVSAvoidrobustness to camera variation
Core Design Contradiction:
Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The invention transforms the identification approach from direct 2D image comparison to 3D shape-based comparison. By estimating three-dimensional shapes of persons from 2D images captured at different angles and comparing these 3D representations, the system achieves viewpoint-invariant identification. This dimensional transformation allows the same person to be identified regardless of camera position or viewing angle.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Area of stationary object

If multiple cameras are installed to cover large-scale areas, then monitoring coverage is improved, but difficulty in detecting and measuring identical subjects increases due to viewpoint differences

Engineering Contradiction:
Improvemonitoring coverageVSAvoidsubject identification difficulty
Core Design Contradiction:
Area of stationary objectVSDifficulty of detecting and measuring

Solution Approach 1:

The invention resolves the difficulty of identifying subjects across multiple cameras by transforming 2D viewpoint-dependent images into 3D viewpoint-independent shape representations. The 3D shape estimation process creates a unified representation that can be compared across different camera perspectives, enabling reliable identification throughout the entire monitored area regardless of how many cameras are deployed.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Measurement precision

If direct image comparison is used for subject identification, then processing complexity is reduced, but identification accuracy deteriorates due to appearance variations

Engineering Contradiction:
Improveidentification accuracyVSAvoidprocessing complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The invention introduces 3D shape estimation as an intermediate processing step that transforms appearance-dependent 2D images into appearance-independent 3D representations. While this adds processing complexity, it enables accurate identification by comparing fundamental geometric properties rather than superficial visual characteristics that vary with lighting, angle, and pose.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Data Source

PatentUS20250148636A1Image processing apparatus, image processing method, and storage medium
Publication Date: 2025.05.08 CANON KK
  • US20250148636A1 patent drawing
  • US20250148636A1 patent drawing
  • US20250148636A1 patent drawing

AI summary

An image processing apparatus includes a first extraction means for extracting a first subject image from a first image captured by a first imaging unit, a second extraction means for extracting a second subject image from a second image captured by a second imaging unit, a first estimation means for estimating a three-dimensional shape of the first subject based on the first subject image, a second estimation means for estimating a second subject state based on the second subject image, an acquisition means for acquiring a predictive image predicted to be acquired when the first subject is captured by the second imaging unit based on the estimation results of the first subject's three-dimensional shape and the second subject's state, and a determination means for determining whether the first subject and the second subject are identical by comparing the predictive image with the second subject image.