Detector Confidence Signals Category Presence, Not Target Visibility, in Cluttered Manipulation

Jul 16, 2026

A new preprint demonstrates that open-vocabulary object detectors maintain nearly constant confidence scores even as the visible portion of a target object drops to one-eighth, and often report the target present in about 90% of scenes, even when only a same-category distractor is visible. This indicates that detector confidence signals the presence of the object category somewhere in the scene, rather than the visibility of the specific target. The finding holds across three detectors, nine object categories, multiple simulators, and real video, and exposes a fundamental flaw in using detector confidence as a proxy for occlusion or visibility.

Why it matters: This work challenges a common assumption in robotics and computer vision, showing that detector confidence cannot reliably indicate object visibility, which impacts evaluation, active perception, and downstream applications.

Full story at: arXiv Computer Vision ↗