Organizations: State Key Laboratory of Human-Machine Hybrid Augmented Intelligence, Institute of Artificial Intelligence and Robotics, Xi’an Jiaotong University · School of Software Engineering, Xi’an Jiaotong University · Harbin Institute of Technology, Shenzhen · Shenzhen University of Advanced Technology
Generalized Category Discovery (GCD) seeks to uncover novel categories in unlabeled data while preserving recognition of known categories, yet prevailing visual-only pipelines and the loose coupling between supervised learning and discovery often yield brittle boundaries on fine-grained, look-alike categories. We introduce the Analogical Textual Concept Generator (ATCG), a plug-and-play module that analogizes from labeled knowledge to new observations, forming textual concepts for unlabeled samples. Fusing these analogical textual concepts with visual features turns discovery into a visual-textual reasoning process, transferring prior knowledge to novel data and sharpening category separation. ATCG attaches to both parametric and clustering style GCD pipelines and requires no changes to their overall design. Across six benchmarks, ATCG consistently improves overall, known-class, and novel-class performance, with the largest gains on fine-grained data. Our code is available at: https://github.com/zhou-9527/AnaLogical-GCD.
Figures & tables
Figure 1: Illustration of an example of human Analogical Learning mechanism and the proposed Analogical Textual Concept Generator (ATCG).
Figure 2: Overview of the AL-GCD Framework . The framework consists of two stages: (1) ATCG training, where the ATCG is trained using labeled images and text embeddings to acquire the ability to generate meaningful analogical text embeddings for unlabeled samples; (2) GCD Training, where ATCG generates text embeddings for unlabeled samples, which are fused with visual embeddings through a fusion head to produce fusion embeddings. These embeddings are optimized via contrastive learning.
Figure 3: Architecture of the Analogical Textual Concept Generator (ATCG), illustrating its input–output tensor structure.
Method
CUB
Stanford Cars
FGVC Aircraft
CIFAR100
ImageNet100
Herbarium19
All
Old
New
All
Old
New
All
Old
New
All
Old
New
All
Old
New
All
Old
New
(a) Clustering with the ground-truth number of categories K given
DINO
GCD (CVPR 22)
51.3
56.6
48.7
39.0
57.6
29.9
45.0
41.1
46.9
73.0
76.2
66.5
74.1
89.8
66.3
35.4
51.0
27.0
GPC (ICCV 23)
55.4
58.2
53.1
42.8
59.2
32.8
46.3
42.5
47.9
77.9
85.0
63.0
76.9
94.3
71.0
-
-
-
SimGCD (ICCV 23)
60.3
65.6
57.7
53.8
71.9
45.0
54.2
59.1
51.8
80.1
81.2
77.8
83.0
93.1
77.9
44.0
58.0
36.4
CMS (CVPR 24)
68.2
76.5
64.0
56.9
76.1
47.6
56.0
63.4
52.3
82.3
85.7
75.5
84.7
95.6
79.2
36.4
54.9
26.4
Table 1: Comparison with the state of the art on GCD. The best results are in bold, the second best are underlined. † denotes reproduced results. △ denotes results from the CMS Appendix [ 6 ] .
Method
Fine-grained
Classification
All Datasets
All
Old
New
All
Old
New
All
Old
New
(a) Clustering with the GT number of categories K given
CPT
65.9
71.3
63.2
85.3
88.3
83.7
68.9
75.3
65.6
GET
71.5
74.8
69.8
86.9
90.6
82.6
73.0
78.4
69.4
CMS △
64.7
74.5
59.9
83.1
89.5
76.3
66.1
76.5
59.6
+ AL-GCD
69.5
75.3
66.7
85.8
90.4
83.0
70.0
77.7
65.8
Table 2: Comparison on Fine-grained Avg, Classification Avg, and All Datasets Avg with CLIP backbone. The best values are in bold and the second best are underlined. † denotes reproduced results. △ denotes results from the CMS appendix [ 6 ] .
ATCG Initial Layer
ATCG Stacked Layers
CIFAR100
ImageNet100
CUB
Stanford Cars
FGVC Aircraft
Herbarium19
All
Old
New
All
Old
New
All
Old
New
All
Old
New
All
Old
New
All
Old
New
✗
✗
81.1
84.2
75.2
89.9
94.2
87.5
69.6
75.8
66.5
69.4
82.2
62.9
53.5
57.9
51.7
47.9
62.3
39.9
✓
✗
83.7
84.3
82.7
90.4
94.9
88.0
73.4
76.7
71.8
74.9
86.1
69.0
56.1
56.5
55.9
48.8
62.9
41.3
✓
✓
84.7
84.5
84.9
92.6
95.3
91.2
74.7
79.6
72.3
78.3
86.3
74.4
58.6
61.5
57.2
50.3
63.6
43.1
Improv. over baseline
+3.6
+0.3
+9.7
+2.7
+1.1
+3.7
+5.1
+3.8
+5.8
+8.9
+4.1
+11.5
+5.1
+3.6
+5.5
+2.4
+1.3
+3.2
Table 3: Ablation study results for ATCG with various initial and stacked layer settings across different datasets.
Num. of ATCG Layers
CUB
CIFAR100
All
Old
New
All
Old
New
0
69.62
75.78
66.53
81.11
84.22
75.23
2
74.73
79.59
72.31
84.67
84.54
84.94
4
74.80
78.48
72.87
84.87
83.77
86.76
6
74.69
78.12
72.97
84.76
83.67
86.63
Table 4: Ablation study on the number of ATCG layers.
Figure 4: Ablation study of the α on Stanford Cars.