3D Object Classification Using Pyramidal HoG Vectors

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Solution Overview

Problem

Virtual experience platforms face challenges in automatically detecting and classifying counterfeit 3D objects, which can disrupt the virtual economy and user experience due to their geometric similarities to authentic objects, making it difficult to distinguish between authentic and inauthentic digital assets.

Innovation Solution

The system generates multiple images of a candidate 3D object from various camera positions, calculates histogram of oriented gradients (HoG) vectors, and determines asset features by concatenating pyramidal HoG vectors, allowing for rotationally invariant comparisons and dimensionality reduction to classify objects as authentic or inauthentic based on vector distances.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If geometric similarity analysis is used to detect counterfeit 3D objects, then detection accuracy is improved, but computational complexity increases due to multiple camera positions and pyramidal HoG vectors

Engineering Contradiction:
Improvedetection accuracyVSAvoidcomputational complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The system segments the 3D object analysis into multiple camera positions and pyramidal levels, processing each segment independently to extract HoG vectors. This segmentation allows comprehensive geometric analysis while organizing computational tasks into manageable units that can be processed systematically.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system transitions from analyzing a single 2D image to analyzing multiple images from different camera positions, adding the dimension of spatial viewing angles. This multi-dimensional approach enables more accurate geometric similarity detection by capturing the 3D object's shape from multiple perspectives.

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

2Measurement precision

If multiple camera positions are used for comprehensive geometric analysis, then classification accuracy is improved, but processing time increases

Engineering Contradiction:
Improveclassification accuracyVSAvoidprocessing time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The system performs preliminary processing by pre-computing HoG vectors for each camera position and pyramidal level before the final similarity comparison. This preliminary extraction of geometric features allows the actual classification to proceed more quickly, as the heavy computational lifting is done in advance.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system creates multiple copies of the 3D object representation from different camera positions and pyramidal levels, then compares these copies against each other and against authentic references. This copying approach enables parallel processing of multiple views simultaneously, improving both accuracy and efficiency.

Inventive Principle:
Principle #26Copying

3Reliability

If pyramidal HoG vectors are used for rotationally invariant comparison, then authenticity detection reliability is improved, but computational resources required increase

Engineering Contradiction:
Improveauthenticity detection reliabilityVSAvoidcomputational resources
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The system adds pyramidal levels to the HoG vector computation, creating a multi-resolution representation of the 3D object. This pyramidal structure allows rotationally invariant comparison by analyzing the object at multiple scales, improving reliability while the hierarchical nature of the pyramid allows efficient computation by processing coarser levels first.

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

Data Source

PatentUS20240331352A1Classification of three-dimensional (3D) objects in a virtual environment
Publication Date: 2024.10.03 ROBLOX CORP
  • US20240331352A1 patent drawing
  • US20240331352A1 patent drawing
  • US20240331352A1 patent drawing

AI summary

Some implementations relate to methods, systems, and computer-readable media for classifying three-dimensional (3D) objects. In some implementations, the method includes generating a plurality of images of a candidate 3D object, determining one or more histogram of oriented gradients (HOG) vectors for each image, determining an asset feature of the candidate 3D object based on the one or more HOG vectors, determining if the asset feature of the candidate 3D object matches an authentic asset feature of at least one authentic 3D object, if the asset feature of the candidate 3D object matches the authentic asset feature of the at least one authentic 3D object, classifying the candidate 3D object as an inauthentic object, and if the asset feature of the candidate 3D object does not match the authentic asset feature of the at least one authentic 3D object, classifying the candidate 3D object as an authentic object.