Prompt and Refinement: Asymmetric Mutual Learning for Infrared Small Target Detection with Noisy Labels

Yimin Fu; Songbo Wang; Lizhuo Liu; Baicheng Pan; Zhunga Liu; Michael K. Ng

cs.CVOct 5, 2026

Prompt and Refinement: Asymmetric Mutual Learning for Infrared Small Target Detection with Noisy Labels

Authors: Yimin Fu, Songbo Wang, Lizhuo Liu, Baicheng Pan, Zhunga Liu, Michael K. Ng

Organizations: Department of Mathematics, Hong Kong Baptist University, Hong Kong, China · School of Automation, Northwestern Polytechnical University, Xi’an, 710072, China · School of Electrical and Control Engineering, Xi’an University of Science and Technology, Xi’an, 710054, China

Abstract

Existing data-driven infrared small target detection (ISTD) methods typically require large-scale datasets with accurate pixel-level annotations for model training. However, such labor-intensive requirements are difficult to satisfy in real-world applications due to the heavy reliance on expert knowledge and the inherently weak distinctiveness of infrared small targets. Consequently, the presence of noisy labels during model training is inevitable, which can severely mislead the learning of target perception toward spurious patterns. To address this challenge, we propose Prompt and Refinement (PAR), a label-noise-robust asymmetric mutual learning paradigm for ISTD. Specifically, PAR comprises a pretrained Segment Anything Model (SAM) and an ISTD-specific detector trained from scratch, which learn collaboratively through a peer-teaching scheme. Coupled with local contrast regularity, the predictions of the two asymmetric peer models are mutually exploited as rectification cues for the supervisory masks of their counterparts. The interaction between complementary inductive biases effectively prevents the label correction process from degenerating into the self-confirmation loop of a single model, enabling progressive refinement of the annotations toward intrinsic target characteristics. In addition, the detector predictions are utilized as corrective mask prompts to facilitate task-specific adaptation of the vision foundation model. Moreover, an evidential uncertainty estimation strategy is introduced into the optimization process to further alleviate the adverse effects of noisy labels. Extensive experiments under diverse noisy label scenarios on three ISTD datasets demonstrate that PAR consistently achieves state-of-the-art performance.

Figures & tables

Fig. 1: The illustration of different types of noisy labels for infrared small targets. Pixels colored in red and green denote false-positive and false-negative annotations, respectively.

Fig. 2: The architecture overview of our proposed PAR for ISTD under noisy-label supervision.

Method	Venue	Dilation & Erosion				Shrinkage				Expansion
Method	Venue	IoU $\uparrow$	$F_{1}\uparrow$	$P_{d}\uparrow$	$F_{a}\downarrow$	IoU $\uparrow$	$F_{1}\uparrow$	$P_{d}\uparrow$	$F_{a}\downarrow$	IoU $\uparrow$	$F_{1}\uparrow$	$P_{d}\uparrow$	$F_{a}\downarrow$
Tophat [ 6 ]	$\text{OE}_{96}$	43.13	32.27	83.49	35.31	43.13	32.27	83.49	35.31	43.13	32.27	83.49	35.31
MPCM [ 7 ]	$\text{PR}_{16}$	24.41	34.65	88.99	17.84	24.41	34.65	88.99	17.84	24.41	34.65	88.99	17.84
ACMNet [ 10 ]	$\text{WACV}_{21}$	48.19	65.03	87.61	54.87	52.23	68.61	91.74	22.42	48.55	65.36	91.42	56.23
DNANet [ 11 ]	$\text{TIP}_{22}$	58.52	73.83	95.66	61.31	61.96	76.51	94.60	12.78	63.74	77.85	94.17	31.91
UIUNet [ 12 ]	$\text{TIP}_{22}$	54.01	70.14	88.78	18.38	68.18	81.08	96.61	16.04	60.08	75.06	94.49	25.07

TABLE I: Comparison of results under different noise types on the NUDT-SIRST dataset in terms of IoU (%),

F_{1}

(%),

P_{d}

(%), and

F_{a}

(

10^{-6}

). The best results are highlighted in bold.

Method	Venue	Dilation & Erosion				Shrinkage				Expansion
Method	Venue	IoU $\uparrow$	$F_{1}\uparrow$	$P_{d}\uparrow$	$F_{a}\downarrow$	IoU $\uparrow$	$F_{1}\uparrow$	$P_{d}\uparrow$	$F_{a}\downarrow$	IoU $\uparrow$	$F_{1}\uparrow$	$P_{d}\uparrow$	$F_{a}\downarrow$
Tophat [ 6 ]	$\text{OE}_{96}$	39.64	36.39	78.41	167.20	39.64	36.39	78.41	167.20	39.64	36.39	78.41	167.20
MPCM [ 7 ]	$\text{PR}_{16}$	12.80	16.62	66.24	207.90	12.80	16.62	66.24	207.90	12.80	16.62	66.24	207.90
ACMNet [ 10 ]	$\text{WACV}_{21}$	57.41	72.94	93.57	9.05	59.51	74.62	91.74	23.24	54.91	70.89	94.49	117.98
DNANet [ 11 ]	$\text{TIP}_{22}$	63.01	77.31	94.49	10.82	70.56	82.74	99.08	14.90	58.88	74.12	95.41	29.81
UIUNet [ 12 ]	$\text{TIP}_{22}$	63.51	77.69	98.16	40.10	69.83	82.24	96.33	10.64	52.56	68.91	99.08	50.38

TABLE II: Comparison of results under different noise types on the NUAA-SIRST dataset in terms of IoU (%),

F_{1}

(%),

P_{d}

(%), and

F_{a}

(

10^{-6}

). The best results are highlighted in bold.

Panel of Figure 5 — Fig. 3: ROC curves of different methods on the NUAA-SIRST and NUDT-SIRST datasets under different label noise scenarios.

Method	Venue	MSHNet [ 39 ]				MTUNet [ 13 ]				L2SKNet [ 40 ]
Method	Venue	IoU $\uparrow$	$F_{1}\uparrow$	$P_{d}\uparrow$	$F_{a}\downarrow$	IoU $\uparrow$	$F_{1}\uparrow$	$P_{d}\uparrow$	$F_{a}\downarrow$	IoU $\uparrow$	$F_{1}\uparrow$	$P_{d}\uparrow$	$F_{a}\downarrow$
baseline	—	45.39	62.43	84.65	29.86	43.10	60.23	76.47	32.39	43.72	60.84	66.45	29.46
+ URN [ 28 ]	$\text{AAAI}_{22}$	46.88	63.84	71.31	23.26	44.21	61.31	69.51	22.91	42.14	59.29	58.54	19.06
+ RMD [ 60 ]	$\text{TMI}_{23}$	41.67	58.83	76.46	17.45	46.72	63.69	79.74	29.83	40.69	57.84	72.24	16.12
+ AIO2 [ 70 ]	$\text{TGRS}_{24}$	43.24	60.37	62.28	18.75	44.11	61.22	56.11	26.86	40.67	57.82	55.48	25.51
+ DSR [ 59 ]	$\text{TNNLS}_{25}$	45.48	62.52	69.52	17.88	47.75	64.64	72.46	15.17	49.69	66.39	71.63	14.85

TABLE III: Comparison of results under different noise types on the NUDT-Sea dataset in terms of IoU (%),

F_{1}

(%),

P_{d}

(%), and

F_{a}

(

10^{-6}

). The best results are highlighted in bold.

Fig. 4: Visualizations of IRSTD results of different methods. Boxes in red, blue, and yellow refer to detected targets, missed detections, and false alarms. Zoomed-in regions of the detected targets are provided in the corner for clear visualization.

AML	JAR	EUE	IoU $\uparrow$	$F_{1}\uparrow$	$P_{d}\uparrow$	$F_{a}\downarrow$
✘	✘	✘	53.26	69.50	90.79	24.61
✘	✘	✔	57.20	72.77	94.17	20.11
✘	✔	✘	65.51	79.16	93.75	17.28
✔	✘	✘	62.52	76.94	95.56	12.11
✔	✘	✔	66.69	80.01	95.66	15.85
✔	✔	✘	67.71	80.74	95.23	11.35

TABLE IV: Ablation experiments about contributions of each component to noisy ISTD. Best results are highlighted in bold.

Panel of Figure 9 — Fig. 5: Ablation experiments for different configurations of architectural and objective asymmetry.

Strategy	Shrinkage $\leftarrow$ $\theta$ $\rightarrow$ Expansion
Strategy	0.3	0.4	0.5	0.6	0.7
Baseline	58.18	66.73	68.47	60.94	55.28
Entropy	57.87	66.84	67.60	62.58	55.08
Variance	58.34	65.60	67.70	64.27	55.20
Sensitivity	59.93	67.68	69.89	65.76	56.76
Evidence	60.98	68.52	70.90	67.59	58.01

TABLE V: Ablation experiments for different uncertainty estimation strategies. Best results are highlighted in bold.

Method	Params (M)	Clean labels		Noisy labels
Method	Params (M)	IoU $\uparrow$	$P_{d}\uparrow$	IoU $\uparrow$	$P_{d}\uparrow$
MTUNet	12.75	61.43	84.54	43.10	76.47
+ RMD	25.50	57.80	72.25	46.72	79.74
+ RoCoT	25.50	55.32	77.01	46.02	62.39
+ PAR	22.05	61.11	84.71	56.55	81.43

TABLE VI: Analysis of computational complexity. Best results are highlighted in bold.

Fig. 6: The performance of PAR with different combinations of $\tau_{p}$ and $\tau_{c}$ .

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