Early Quantization Shrinks Codebook: A Simple Fix for Diversity-Preserving Tokenization

Fuente: arXiv
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Main Authors: Zhao, Wenhao, Zou, Qiran, Shah, Rushi, Wu, Yudi, Lin, Zhouhan, Liu, Dianbo
Format: Preprint
Published: 2026
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author Zhao, Wenhao
Zou, Qiran
Shah, Rushi
Wu, Yudi
Lin, Zhouhan
Liu, Dianbo
author_facet Zhao, Wenhao
Zou, Qiran
Shah, Rushi
Wu, Yudi
Lin, Zhouhan
Liu, Dianbo
contents Vector quantization is a technique in machine learning that discretizes continuous representations into a set of discrete vectors. It is widely employed in tokenizing data representations for large language models, diffusion models, and other generative models. Despite its prevalence, the characteristics and behaviors of vector quantization in generative models remain largely underexplored. In this study, we systematically investigate the issue of collapses in vector quantization, where collapsed representations are observed across discrete codebook tokens and continuous latent embeddings. By leveraging both synthetic and real datasets, we identify the severity of each type of collapses and triggering conditions. Our analysis reveals that random initialization and limited encoder capacity result in tokens collapse and embeddings collapse. Building on these findings, we propose potential solutions aimed at mitigating each collapse. To the best of our knowledge, this is the first comprehensive study examining representation collapsing problems in vector quantization.
format Preprint
id arxiv_https___arxiv_org_abs_2603_17052
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Early Quantization Shrinks Codebook: A Simple Fix for Diversity-Preserving Tokenization
Zhao, Wenhao
Zou, Qiran
Shah, Rushi
Wu, Yudi
Lin, Zhouhan
Liu, Dianbo
Machine Learning
Artificial Intelligence
Vector quantization is a technique in machine learning that discretizes continuous representations into a set of discrete vectors. It is widely employed in tokenizing data representations for large language models, diffusion models, and other generative models. Despite its prevalence, the characteristics and behaviors of vector quantization in generative models remain largely underexplored. In this study, we systematically investigate the issue of collapses in vector quantization, where collapsed representations are observed across discrete codebook tokens and continuous latent embeddings. By leveraging both synthetic and real datasets, we identify the severity of each type of collapses and triggering conditions. Our analysis reveals that random initialization and limited encoder capacity result in tokens collapse and embeddings collapse. Building on these findings, we propose potential solutions aimed at mitigating each collapse. To the best of our knowledge, this is the first comprehensive study examining representation collapsing problems in vector quantization.
title Early Quantization Shrinks Codebook: A Simple Fix for Diversity-Preserving Tokenization
topic Machine Learning
Artificial Intelligence
url https://arxiv.org/abs/2603.17052