Papers › Which Tokens to Use? Investigating Token Reduction in Vision Transformers

Which Tokens to Use? Investigating Token Reduction in Vision Transformers

9 Aug 2023arXiv:2308.04657archive 2025-07-28

Joakim Bruslund Haurum, Sergio Escalera, Graham W. Taylor, Thomas B. Moeslund

Since the introduction of the Vision Transformer (ViT), researchers have sought to make ViTs more efficient by removing redundant information in the processed tokens. While different methods have been explored to achieve this goal, we still lack understanding of the resulting reduction patterns and how those patterns differ across token reduction methods and datasets. To close this gap, we set out to understand the reduction patterns of 10 different token reduction methods using four image classification datasets. By systematically comparing these methods on the different classification tasks, we find that the Top-K pruning method is a surprisingly strong baseline. Through in-depth analysis of the different methods, we determine that: the reduction patterns are generally not consistent when varying the capacity of the backbone model, the reduction patterns of pruning-based methods significantly differ from fixed radial patterns, and the reduction patterns of pruning-based methods are correlated across classification datasets. Finally we report that the similarity of reduction patterns is a moderate-to-strong proxy for model performance. Project page at https://vap.aau.dk/tokens.

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JoakimHaurum/TokenReduction mentioned on GitHubpytorchMIT report

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batch_index_select JoakimHaurum/TokenReduction/models/dyvit.py community (archive-listed) ran · our draft was wrong MIT (permissive) · 908619be92da9903 · report
batched_index_select JoakimHaurum/TokenReduction/models/ats.py community (archive-listed) ran · our draft was wrong MIT (permissive) · 582b2f1aa69315a0 · report
build_nabirds_transform JoakimHaurum/TokenReduction/datasets.py community (archive-listed) ran MIT (permissive) · df3ccc72b60b293e · report
cluster_dpc_knn JoakimHaurum/TokenReduction/models/dpcknn.py community (archive-listed) ran MIT (permissive) · 6968174cad423485 · report
index_points JoakimHaurum/TokenReduction/models/dpcknn.py community (archive-listed) ran MIT (permissive) · 1e125c8d8e5f4f15 · report
merge_tokens JoakimHaurum/TokenReduction/models/dpcknn.py community (archive-listed) ran MIT (permissive) · 2f8afc8e34c74e5f · report
checkpoint_filter_fn JoakimHaurum/TokenReduction/models/deit_viz.py community (archive-listed) unverified MIT (permissive) · 5dac11fdc41c896b · report
resize_pos_embed JoakimHaurum/TokenReduction/models/deit_viz.py community (archive-listed) unverified MIT (permissive) · 1dbef2d4da4ee10f · report

Tasks

ClassificationImage ClassificationToken Reductionimage-classification

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Methods

Absolute Position EncodingsAdamAttentionBPEDense ConnectionsDropoutLabel SmoothingLayer NormalizationLinear LayerMulti-Head AttentionPosition-Wise Feed-Forward LayerPruningResidual ConnectionSoftmaxTransformerVision Transformer

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