Vision Transformer Head Pruning for Lightweight Deployment

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Solution Overview

Problem

Vision transformers require a large number of parameters, making them unsuitable for deployment on lightweight devices due to increased model size and computational resources, which existing pruning methods for other models are ineffective for.

Innovation Solution

Structured pruning of vision transformers using multi-granularity sparsity across attention heads and MLP layers, employing a graph-based approach to rank importance and a soft-pruning strategy with optimization techniques to maintain model accuracy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If vision transformers use many parameters to define the model, then model accuracy and performance are improved, but model size and computational resources increase significantly

Engineering Contradiction:
Improvemodel accuracyVSAvoidnumber of parameters
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The patent segments the vision transformer model into multiple attention heads and MLP layers, applying structured pruning at different granular levels. Each attention head can be independently pruned, allowing selective removal of less important parameters while preserving the overall model architecture and performance.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies local quality by differentiating the importance of different parameters within the model. Not all parameters are treated equally - instead, parameters are ranked by importance using graph-based methods, and pruning is applied selectively to less important parameters while retaining critical ones.

Inventive Principle:
Principle #3Local quality

2Reliability

If vision transformers use many parameters to define the model, then model accuracy and performance are improved, but deployment on lightweight devices becomes unsuitable

Engineering Contradiction:
Improvemodel accuracyVSAvoidcomputational resources
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent segments the vision transformer model into multiple attention heads and MLP layers, applying structured pruning at different granular levels. Each attention head can be independently pruned, allowing selective removal of less important parameters while preserving the overall model architecture and performance.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent changes the parameter configuration of the vision transformer by reducing the number of parameters through structured pruning. The model transitions from a dense parameter configuration to a sparse one, where only the most important parameters are retained, making it suitable for deployment on lightweight devices.

Inventive Principle:
Principle #35Parameter changes

3Quantity of substance

If existing pruning methods for other models are applied to vision transformers, then model size is reduced, but pruning effectiveness is insufficient

Engineering Contradiction:
Improvemodel sizeVSAvoidpruning effectiveness
Core Design Contradiction:
Quantity of substanceVSReliability

Solution Approach 1:

The patent applies local quality by differentiating the importance of different parameters within the model. Not all parameters are treated equally - instead, parameters are ranked by importance using graph-based methods, and pruning is applied selectively to less important parameters while retaining critical ones.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent introduces a dynamic pruning strategy where the pruning process is iterative and adaptive. The model is pruned in stages with fine-tuning between stages, allowing the pruning to adapt to the specific characteristics of vision transformers and maintain performance while reducing size.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentUS12548317B2Structured pruning of vision transformer
Publication Date: 2026.02.10 SAMSUNG ELECTRONICS CO LTD
  • US12548317B2 patent drawing
  • US12548317B2 patent drawing
  • US12548317B2 patent drawing

AI summary

In one embodiment, a method includes accessing a batch B of a plurality of images, wherein each image in the batch is part of a training set of images used to train a vision transformer comprising a plurality of attention heads. The method further includes determining, for each attention head A, a similarity between (1) the output of the attention head evaluated using each image in the batch and the (2) output of each attention head evaluated using each image in the batch. The method further includes determining, based on the determined similarities, an importance score for each attention head; and pruning, based on the importance scores, one or more attention heads from the vision transformer.