arXiv Computer Vision

Hierarchical Prompt Learning for Hyperbolic Vision-Language Models

arXiv Machine Learning
Oct 21

Hierarchical Semantic Tree Anchoring for CLIP-Based Class-Incremental Learning

The paper introduces HASTEN, a hierarchical semantic tree anchoring framework that enhances CLIP-based class‑incremental learning by incorporating external hierarchical knowledge into hyperbolic space. By treating classes as part of a structured hierarchy rather than isolated labels, HASTEN stabilizes visual and textual feature mappings, reduces feature drift, and mitigates catastrophic forgetting across incremental tasks. Experiments on nine benchmarks demonstrate that HASTEN consistently outperforms existing methods.

By Tao Hu, Lan Li, Zhen-Hao Xie, Da-Wei Zhou
arXiv Computer Vision
Oct 26

Separating Angular Alignment from Radial Ordering in Hyperbolic Vision-Language Models

The paper introduces AURORA, a hyperbolic vision‑language framework that separates angular alignment from radial ordering. Angular alignment captures semantic similarity while a novel Radial‑Angular Order Cone (RAOC) models hierarchical entailment based on parent‑child radial gaps. The approach includes norm regularization to prevent radial degeneration and is evaluated on large image‑text datasets, outperforming both Euclidean and hyperbolic baselines in zero‑shot classification, retrieval, hierarchical reasoning, and compositional understanding.

By Mingyang Gao, Yuwei Wu, Shiyu Luo, Wei Wu, Xiaomeng Fan, Qihao Lv, Haoyu Zhang, Rui Gao, Bingzhen Liu, Zhi Gao, Che Sun
arXiv Computer Vision
Aug 26

What Does Prompt Learning Change? -A Natural-Language Concept Analysis of Vision-Language Models

Prompt learning modifies vision‑language models by optimizing continuous prompt vectors, yet the resulting prompts are hard to interpret in natural language. PromptSpLiCE is a post‑hoc method that rewrites each class‑conditioned text embedding as a sparse mix of concepts from a fixed dictionary, enabling a direct comparison of concept profiles before and after prompt learning. Across 11 image‑classification datasets, the method shows that only about 1.6 of the initial top‑10 concepts remain after learning, and that larger profile changes correlate with higher accuracy gains, while a derived gradient expression offers geometric insight into loss sensitivity.

By Ryo Kamiya, Hiroshi Kera, Kazuhiko Kawamoto
arXiv Computer Vision
Sep 28

ProCAP: Probabilistic Cross-Attentive Prompt Learning for Vision-Language Models

ProCAP introduces a probabilistic cross-attentive prompt learning framework for vision-language models like CLIP, enabling improved cross-modal interaction without updating the backbone. It jointly learns visual and textual prompt tokens, linking them via stacked bidirectional multi-head cross-attention to refine each branch across prompt depth. The method incorporates Gaussian parameterization of prompt tokens, lightweight KL and L2 regularization, and a compact symmetric InfoNCE head to align image features with class-level text representations, achieving strong few-shot base-to-novel performance and competitive transfer results across multiple datasets and benchmarks.

By Hiwa Azeez Abbas, Fatemeh Daneshfar, Moloud Abdar