Convergence of Mean Shift Algorithms for Large Bandwidths and Simultaneous Accurate Clustering
- URL: http://arxiv.org/abs/2506.19837v1
- Date: Tue, 24 Jun 2025 17:53:29 GMT
- Title: Convergence of Mean Shift Algorithms for Large Bandwidths and Simultaneous Accurate Clustering
- Authors: Susovan Pal, Praneeth Vepakomma,
- Abstract summary: Mean shift (MS) is a non-parametric, density-based, iterative algorithm that has prominent usage in clustering and image segmentation.<n>We show that for textit sufficiently large bandwidth convergence is guaranteed in any dimension with textitany radially symmetric and strictly positive definite kernels.
- Score: 3.038423178022283
- License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
- Abstract: The mean shift (MS) is a non-parametric, density-based, iterative algorithm that has prominent usage in clustering and image segmentation. A rigorous proof for its convergence in full generality remains unknown. Two significant steps in this direction were taken in the paper \cite{Gh1}, which proved that for \textit{sufficiently large bandwidth}, the MS algorithm with the Gaussian kernel always converges in any dimension, and also by the same author in \cite{Gh2}, proved that MS always converges in one dimension for kernels with differentiable, strictly decreasing, convex profiles. In the more recent paper \cite{YT}, they have proved the convergence in more generality,\textit{ without any restriction on the bandwidth}, with the assumption that the KDE $f$ has a continuous Lipschitz gradient on the closure of the convex hull of the trajectory of the iterated sequence of the mode estimate, and also satisfies the {\L}ojasiewicz property there. The main theoretical result of this paper is a generalization of those of \cite{Gh1}, where we show that (1) for\textit{ sufficiently large bandwidth} convergence is guaranteed in any dimension with \textit{any radially symmetric and strictly positive definite kernels}. The proof uses two alternate characterizations of radially symmetric positive definite smooth kernels by Schoenberg and Bernstein \cite{Fass}, and borrows some steps from the proofs in \cite{Gh1}. Although the authors acknowledge that the result in that paper is more restrictive than that of \cite{YT} due to the lower bandwidth limit, it uses a different set of assumptions than \cite{YT}, and the proof technique is different.
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