Papers › OrdinalCLIP: Learning Rank Prompts for Language-Guided Ordinal Regression

OrdinalCLIP: Learning Rank Prompts for Language-Guided Ordinal Regression

6 Jun 2022arXiv:2206.02338archive 2025-07-28

Wanhua Li, Xiaoke Huang, Zheng Zhu, Yansong Tang, Xiu Li, Jie zhou, Jiwen Lu

This paper presents a language-powered paradigm for ordinal regression. Existing methods usually treat each rank as a category and employ a set of weights to learn these concepts. These methods are easy to overfit and usually attain unsatisfactory performance as the learned concepts are mainly derived from the training set. Recent large pre-trained vision-language models like CLIP have shown impressive performance on various visual tasks. In this paper, we propose to learn the rank concepts from the rich semantic CLIP latent space. Specifically, we reformulate this task as an image-language matching problem with a contrastive objective, which regards labels as text and obtains a language prototype from a text encoder for each rank. While prompt engineering for CLIP is extremely time-consuming, we propose OrdinalCLIP, a differentiable prompting method for adapting CLIP for ordinal regression. OrdinalCLIP consists of learnable context tokens and learnable rank embeddings; The learnable rank embeddings are constructed by explicitly modeling numerical continuity, resulting in well-ordered, compact language prototypes in the CLIP space. Once learned, we can only save the language prototypes and discard the huge language model, resulting in zero additional computational overhead compared with the linear head counterpart. Experimental results show that our paradigm achieves competitive performance in general ordinal regression tasks, and gains improvements in few-shot and distribution shift settings for age estimation. The code is available at https://github.com/xk-huang/OrdinalCLIP.

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Code

xk-huang/OrdinalCLIP officialmentioned in papermentioned on GitHubpytorchMIT report

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Tasks

Aesthetics Quality AssessmentAge EstimationFew-shot Age EstimationHistorical Color Image DatingLanguage ModellingPrompt Engineeringregression

Results from the paper archive 2025-07-28

TaskDatasetModelMetricValueRank at snapshotLeaderboardReport
Aesthetics Quality Assessment Image Aesthetics dataset OrdinalCLIP Accuracy 73.05 #1 of 4 Archive leaderboard report
Aesthetics Quality Assessment Image Aesthetics dataset OrdinalCLIP MAE 0.280 #1 of 4 Archive leaderboard report
Age Estimation Adience OrdinalCLIP Accuracy 61.2 #1 of 5 Archive leaderboard report
Age Estimation Adience OrdinalCLIP MAE 0.47 #1 of 5 Archive leaderboard report
Age Estimation MORPH album2 (Caucasian) OrdinalCLIP MAE 2.32 #4 of 11 Archive leaderboard report
Few-shot Age Estimation MORPH Album2 OrdinalCLIP MAE 4.94 #1 of 2 Archive leaderboard report
Few-shot Age Estimation MORPH Album2 OrdinalCLIP MAE (16 shot) 3.07 #1 of 2 Archive leaderboard report
Few-shot Age Estimation MORPH Album2 OrdinalCLIP MAE (2 shot) 4.36 #1 of 2 Archive leaderboard report
Few-shot Age Estimation MORPH Album2 OrdinalCLIP MAE (4 shot) 3.55 #1 of 2 Archive leaderboard report
Few-shot Age Estimation MORPH Album2 OrdinalCLIP MAE (8 shot) 3.31 #1 of 2 Archive leaderboard report
Historical Color Image Dating HCI OrdinalCLIP MAE 0.67 #1 of 6 Archive leaderboard report
Historical Color Image Dating HCI OrdinalCLIP accuracy 56.44 #1 of 6 Archive leaderboard report

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Methods

CLIP

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