Homography Attention Module for Multi-View Object Detection

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Solution Overview

Problem

Current multi-view object detection methods face challenges in accurately matching features from different view angles due to viewpoint changes and occlusions, and require significant computational resources, with not all features from each view angle being equally useful for accurate aggregation.

Innovation Solution

The proposed method employs a homography attention module that performs channel and spatial attention on images from multiple cameras before homographically transforming them onto multiple height planes, selecting only top-k channel attention scores and spatial features for each height plane, and then aggregates these features using a BEV heatmap generator to improve detection accuracy and reduce computational load.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If all features from multiple camera views are aggregated through homography transformation, then object detection accuracy improves, but computational load increases significantly

Engineering Contradiction:
Improveobject detection accuracyVSAvoidcomputational load
Core Design Contradiction:
Measurement precisionVSPower

Solution Approach 1:

The patent extracts only the most relevant features from multiple camera views by applying channel attention and spatial attention mechanisms. The channel attention module identifies important feature channels, while the spatial attention module highlights significant spatial regions, thereby extracting only the essential features needed for accurate object detection without processing all features, thus reducing computational load.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent applies local quality by using attention mechanisms that assign different weights to different spatial locations and feature channels. The spatial attention module generates location-specific weights, and the channel attention module assigns importance weights to different feature channels, allowing the system to focus computational resources on locally important features rather than treating all features equally.

Inventive Principle:
Principle #3Local quality

2Measurement precision

If channel attention and spatial attention are applied to all feature maps before homography transformation, then feature matching accuracy improves, but processing time increases

Engineering Contradiction:
Improvefeature matching accuracyVSAvoidprocessing time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent applies preliminary action by performing channel attention and spatial attention operations before the homography transformation. The channel attention module processes feature maps to generate channel-wise attention weights, and the spatial attention module generates spatial-wise attention weights in advance, preparing the features for more efficient subsequent processing and matching after transformation.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent extracts only the most relevant features through attention mechanisms before transformation. By identifying and emphasizing important feature channels and spatial regions in advance, the system reduces the amount of data that needs to be processed during and after homography transformation, thereby reducing overall processing time.

Inventive Principle:
Principle #2Taking out (Extraction)

3Power

If top-k channel attention scores are selected for each height plane, then computational requirements are reduced, but detection accuracy may be compromised

Engineering Contradiction:
Improvecomputational requirementsVSAvoiddetection accuracy
Core Design Contradiction:
PowerVSMeasurement precision

Solution Approach 1:

The patent applies partial action by selecting only the top-k channel attention scores for each height plane instead of using all channel scores. This selective approach processes only the most important feature channels, reducing computational requirements while maintaining detection accuracy by focusing on the most relevant features for each specific height plane.

Inventive Principle:
Principle #16Partial or excessive action

Solution Approach 2:

The patent applies local quality by adapting the feature selection to each height plane's specific requirements. Different height planes receive different sets of top-k channel attention scores based on their unique characteristics, allowing the system to optimize computational resources for each local region's detection needs rather than using a uniform approach.

Inventive Principle:
Principle #3Local quality

4Adaptability or versatility

If homography transformation is performed onto multiple height planes, then robustness to viewpoint changes improves, but device complexity increases

Engineering Contradiction:
Improverobustness to viewpoint changesVSAvoiddevice complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent applies dimensionality change by performing homography transformations onto multiple height planes (different Z-depths) rather than a single ground plane. This multi-planar approach captures objects at various distances and viewpoints more effectively, improving robustness to viewpoint changes by representing the scene in multiple depth dimensions simultaneously.

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

Solution Approach 2:

The patent segments the transformation process by dividing it into multiple independent height plane transformations. Each height plane is processed separately with its own homography matrix and attention mechanisms, allowing the system to manage complexity through modular processing of distinct depth layers rather than attempting a single complex transformation.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP4287072A1Methods for performing multi-view object detection by using homography attention module and devices using the same
Publication Date: 2023.12.06 DEEPING SOURCE INC
  • EP4287072A1 patent drawingFigure 1
  • EP4287072A1 patent drawingFigure 2
  • EP4287072A1 patent drawingFigure 3

AI summary

A method for training a homography attention module (HAM) to perform multi-view object detection includes steps of: generating, from an i-th feature map corresponding to each of multiple training images representing multi-views of a target space, a 1-st to a d-th channel attention map for determining channel attention scores each channel included in the i-th feature map has for each of a 1-st to a d-th height plane of the target space, generating a 1-st to a d-th channel refined feature map by referring to channels with top k channel attention scores for each height, element-wisely multiplying them with corresponding spatial attention map generated therefrom to produce a 1-st to a d-th spatial refined feature map, and then homographically transforming them onto corresponding height plane and aggregating them to generate a BEV occupancy heatmap, which is used with its GT for training.