Raising the bar on the evaluation of out-of-distribution detection

In image classification, a lot of development has happened in detecting out-of-distribution (OoD) data. However, most OoD detection methods are evaluated on a standard set of datasets, arbitrarily different from training data. There is no clear definition of what forms a "good" OoD dataset...

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Main Authors: Mukhoti, J, Lin, T-Y, Chen, B-C, Shah, A, Torr, PHS, Dokania, PK, Lim, S-N
Format: Conference item
Language:English
Published: EEE 2023
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author Mukhoti, J
Lin, T-Y
Chen, B-C
Shah, A
Torr, PHS
Dokania, PK
Lim, S-N
author_facet Mukhoti, J
Lin, T-Y
Chen, B-C
Shah, A
Torr, PHS
Dokania, PK
Lim, S-N
author_sort Mukhoti, J
collection OXFORD
description In image classification, a lot of development has happened in detecting out-of-distribution (OoD) data. However, most OoD detection methods are evaluated on a standard set of datasets, arbitrarily different from training data. There is no clear definition of what forms a "good" OoD dataset. Furthermore, the state-of-the-art OoD detection methods already achieve near perfect results on these standard benchmarks. In this paper, we define 2 categories of OoD data using the subtly different concepts of perceptual/visual and semantic similarity to in-distribution (iD) data. We define Near OoD samples as perceptually similar but semantically different from iD samples, and Shifted samples as points which are visually different but semantically akin to iD data. We then propose a GAN based framework for generating OoD samples from each of these 2 categories, given an iD dataset. Through extensive experiments on MNIST, CIFAR-10/100 and ImageNet, we show that a) state-of-the-art OoD detection methods which perform exceedingly well on conventional benchmarks are significantly less robust to our proposed benchmark. Moreover, we observe that b) models performing well on our setup also perform well on conventional real-world OoD detection benchmarks and vice versa, thereby indicating that one might not even need a separate OoD set, to reliably evaluate performance in OoD detection.
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spelling oxford-uuid:f22c31df-9cbb-4292-a1a0-8faaa5c390282024-05-16T12:03:00ZRaising the bar on the evaluation of out-of-distribution detectionConference itemhttp://purl.org/coar/resource_type/c_5794uuid:f22c31df-9cbb-4292-a1a0-8faaa5c39028EnglishSymplectic ElementsEEE2023Mukhoti, JLin, T-YChen, B-CShah, ATorr, PHSDokania, PKLim, S-NIn image classification, a lot of development has happened in detecting out-of-distribution (OoD) data. However, most OoD detection methods are evaluated on a standard set of datasets, arbitrarily different from training data. There is no clear definition of what forms a "good" OoD dataset. Furthermore, the state-of-the-art OoD detection methods already achieve near perfect results on these standard benchmarks. In this paper, we define 2 categories of OoD data using the subtly different concepts of perceptual/visual and semantic similarity to in-distribution (iD) data. We define Near OoD samples as perceptually similar but semantically different from iD samples, and Shifted samples as points which are visually different but semantically akin to iD data. We then propose a GAN based framework for generating OoD samples from each of these 2 categories, given an iD dataset. Through extensive experiments on MNIST, CIFAR-10/100 and ImageNet, we show that a) state-of-the-art OoD detection methods which perform exceedingly well on conventional benchmarks are significantly less robust to our proposed benchmark. Moreover, we observe that b) models performing well on our setup also perform well on conventional real-world OoD detection benchmarks and vice versa, thereby indicating that one might not even need a separate OoD set, to reliably evaluate performance in OoD detection.
spellingShingle Mukhoti, J
Lin, T-Y
Chen, B-C
Shah, A
Torr, PHS
Dokania, PK
Lim, S-N
Raising the bar on the evaluation of out-of-distribution detection
title Raising the bar on the evaluation of out-of-distribution detection
title_full Raising the bar on the evaluation of out-of-distribution detection
title_fullStr Raising the bar on the evaluation of out-of-distribution detection
title_full_unstemmed Raising the bar on the evaluation of out-of-distribution detection
title_short Raising the bar on the evaluation of out-of-distribution detection
title_sort raising the bar on the evaluation of out of distribution detection
work_keys_str_mv AT mukhotij raisingthebarontheevaluationofoutofdistributiondetection
AT linty raisingthebarontheevaluationofoutofdistributiondetection
AT chenbc raisingthebarontheevaluationofoutofdistributiondetection
AT shaha raisingthebarontheevaluationofoutofdistributiondetection
AT torrphs raisingthebarontheevaluationofoutofdistributiondetection
AT dokaniapk raisingthebarontheevaluationofoutofdistributiondetection
AT limsn raisingthebarontheevaluationofoutofdistributiondetection