Saved in:
Bibliographic Details
Main Authors: Prasad, Renjith, Sharma, Rishabh, Shao, Andrew E., Koomthanam, Annmary Justine, Kulkarni, Shreyas, Bhattacharya, Suparna, Foltin, Martin, Sheth, Amit, Orozco, David, Quinn, Matthew, Sammuli, Brian
Format: Preprint
Published: 2026
Subjects:
Online Access:https://arxiv.org/abs/2604.22990
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866918470588825600
author Prasad, Renjith
Sharma, Rishabh
Shao, Andrew E.
Koomthanam, Annmary Justine
Kulkarni, Shreyas
Bhattacharya, Suparna
Foltin, Martin
Sheth, Amit
Orozco, David
Quinn, Matthew
Sammuli, Brian
author_facet Prasad, Renjith
Sharma, Rishabh
Shao, Andrew E.
Koomthanam, Annmary Justine
Kulkarni, Shreyas
Bhattacharya, Suparna
Foltin, Martin
Sheth, Amit
Orozco, David
Quinn, Matthew
Sammuli, Brian
contents Subtle visual anomalies such as hairline cracks, sub-millimeter voids, and low-contrast inclusions are structurally atypical yet visually ambiguous, making them both difficult to annotate and easy to overlook during active learning. Standard acquisition heuristics based on discriminative uncertainty or feature diversity often overselect dominant patterns while underexploring sparse yet important regions of the data space. This failure mode is especially severe in industrial defect inspection, where anomalies may be both low-prevalence and difficult to distinguish from surrounding structure. To resolve this, we propose GSAL, an active learning framework for object detection that combines a diffusion-based difficulty signal with a hierarchical semantic coverage prior. The diffusion component scores images and proposals using reconstruction discrepancy and denoising variability, prioritizing visually atypical or ambiguous examples. However, diffusion alone does not prevent acquisition from repeatedly favoring hard samples within dominant semantic modes. The semantic component therefore organizes candidate samples in a three-level concept graph and promotes coverage of underrepresented semantic regions while providing interpretable acquisition rationales. By balancing visual difficulty with semantic coverage, GSAL improves retrieval of subtle and rare targets that are often missed by uncertainty-only selection. Experiments on a proprietary thin-film defect, Pascal VOC and MS COCO dataset show consistent gains in label efficiency and rare-class retrieval over uncertainty-, diversity-, and hybrid-based baselines
format Preprint
id arxiv_https___arxiv_org_abs_2604_22990
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Hard to See, Hard to Label: Generative and Symbolic Acquisition for Subtle Visual Phenomena
Prasad, Renjith
Sharma, Rishabh
Shao, Andrew E.
Koomthanam, Annmary Justine
Kulkarni, Shreyas
Bhattacharya, Suparna
Foltin, Martin
Sheth, Amit
Orozco, David
Quinn, Matthew
Sammuli, Brian
Computer Vision and Pattern Recognition
Artificial Intelligence
Subtle visual anomalies such as hairline cracks, sub-millimeter voids, and low-contrast inclusions are structurally atypical yet visually ambiguous, making them both difficult to annotate and easy to overlook during active learning. Standard acquisition heuristics based on discriminative uncertainty or feature diversity often overselect dominant patterns while underexploring sparse yet important regions of the data space. This failure mode is especially severe in industrial defect inspection, where anomalies may be both low-prevalence and difficult to distinguish from surrounding structure. To resolve this, we propose GSAL, an active learning framework for object detection that combines a diffusion-based difficulty signal with a hierarchical semantic coverage prior. The diffusion component scores images and proposals using reconstruction discrepancy and denoising variability, prioritizing visually atypical or ambiguous examples. However, diffusion alone does not prevent acquisition from repeatedly favoring hard samples within dominant semantic modes. The semantic component therefore organizes candidate samples in a three-level concept graph and promotes coverage of underrepresented semantic regions while providing interpretable acquisition rationales. By balancing visual difficulty with semantic coverage, GSAL improves retrieval of subtle and rare targets that are often missed by uncertainty-only selection. Experiments on a proprietary thin-film defect, Pascal VOC and MS COCO dataset show consistent gains in label efficiency and rare-class retrieval over uncertainty-, diversity-, and hybrid-based baselines
title Hard to See, Hard to Label: Generative and Symbolic Acquisition for Subtle Visual Phenomena
topic Computer Vision and Pattern Recognition
Artificial Intelligence
url https://arxiv.org/abs/2604.22990