timm documentation
ResNetV2 (BiT)
ResNetV2 (BiT)
Category: CNN · Code: timm/models/resnetv2.py · Architectures: 20 · Pretrained weights: 24 (18 with ImageNet-1k results)
Pre-activation ResNet (v2) with Group Normalization and Weight Standardization as used by Big Transfer (BiT), with the original BiT weights. Also supports the non pre-activation variant used as the hybrid Vision Transformer backbone.
Papers
- Big Transfer (BiT): General Visual Representation Learning
- An Image is Worth 16x16 Words: Transformers for Image Recognition at Scale
- Knowledge distillation: A good teacher is patient and consistent
- Identity Mappings in Deep Residual Networks
Usage
See the Quickstart for loading pretrained weights, image preprocessing and fine-tuning, and Feature Extraction for using the models as backbones.
>>> import timm
>>> model = timm.create_model('resnetv2_50.a1h_in1k', pretrained=True)
>>> data_config = timm.data.resolve_model_data_config(model)Model API support
✓ supported, ✓ (square) works for square sizes only, ✗ not supported, – not needed (the model already accepts any input
size). Checked by running each feature on a randomly initialized model (ResNetV2 with resnetv2_18 at 224), other
architectures of the same class are expected to behave the same. See the Model API page for details.
Architectures
| Architecture | Params (M) | GMACs | Input size | Pretrained weights |
|---|---|---|---|---|
resnetv2_18 | 11.69 | 1.82 | 224 | 1 |
resnetv2_18d | 11.71 | 2.06 | 224 | 1 |
resnetv2_34 | 21.80 | 3.67 | 224 | 1 |
resnetv2_34d | 21.82 | 3.91 | 224 | 2 |
resnetv2_50 | 25.55 | 4.11 | 224 | 1 |
resnetv2_50d | 25.57 | 4.35 | 224 | 0 |
resnetv2_50d_evos | 25.59 | 4.33 | 224 | 1 |
resnetv2_50d_frn | 25.59 | 4.33 | 224 | 0 |
resnetv2_50d_gn | 25.57 | 4.38 | 224 | 1 |
resnetv2_50t | 25.57 | 4.32 | 224 | 0 |
resnetv2_50x1_bit | 25.55 | 4.23 | 224 | 3 |
resnetv2_50x3_bit | 217.32 | 145.70 | 448 | 2 |
resnetv2_101 | 44.54 | 7.83 | 224 | 1 |
resnetv2_101d | 44.56 | 8.07 | 224 | 0 |
resnetv2_101x1_bit | 44.54 | 31.65 | 448 | 2 |
resnetv2_101x3_bit | 387.93 | 280.33 | 448 | 2 |
resnetv2_152 | 60.19 | 11.55 | 224 | 0 |
resnetv2_152d | 60.20 | 11.80 | 224 | 0 |
resnetv2_152x2_bit | 236.34 | 46.95 | 224 | 4 |
resnetv2_152x4_bit | 936.53 | 844.84 | 480 | 2 |
GMACs and parameter counts are for the default input size and classifier of each architecture, from the benchmark results.
Pretrained weights
Top-1 is ImageNet-1k validation accuracy from results-imagenet.csv at
the listed eval size, - if the weight has no ImageNet-1k result (e.g. pretraining or image-text weights). Classes is the
size of the pretrained classifier, none for weights without one.
Weights are grouped by source: the paper or origin given in the pretrained config, else a Hub organization other than timm, else the first part of the pretrained tag (architecture.tag). Sources with a single weight are listed under
other.
goog tags
| Weight | Input size | Top-1 (%) | Eval size | Classes | License | Hub |
|---|---|---|---|---|---|---|
resnetv2_50x1_bit.goog_distilled_in1k | 224 | 82.820 | 224 | 1000 | apache-2.0 | timm |
resnetv2_50x1_bit.goog_in21k | 224 | - | - | 21843 | apache-2.0 | timm |
resnetv2_50x1_bit.goog_in21k_ft_in1k | 448 | 80.386 | 448 | 1000 | apache-2.0 | timm |
resnetv2_50x3_bit.goog_in21k | 224 | - | - | 21843 | apache-2.0 | timm |
resnetv2_50x3_bit.goog_in21k_ft_in1k | 448 | 83.982 | 448 | 1000 | apache-2.0 | timm |
resnetv2_101x1_bit.goog_in21k | 224 | - | - | 21843 | apache-2.0 | timm |
resnetv2_101x1_bit.goog_in21k_ft_in1k | 448 | 82.332 | 448 | 1000 | apache-2.0 | timm |
resnetv2_101x3_bit.goog_in21k | 224 | - | - | 21843 | apache-2.0 | timm |
resnetv2_101x3_bit.goog_in21k_ft_in1k | 448 | 84.430 | 448 | 1000 | apache-2.0 | timm |
resnetv2_152x2_bit.goog_in21k | 224 | - | - | 21843 | apache-2.0 | timm |
resnetv2_152x2_bit.goog_in21k_ft_in1k | 448 | 84.468 | 448 | 1000 | apache-2.0 | timm |
resnetv2_152x2_bit.goog_teacher_in21k_ft_in1k | 224 | 82.918 | 224 | 1000 | apache-2.0 | timm |
resnetv2_152x2_bit.goog_teacher_in21k_ft_in1k_384 | 384 | 83.858 | 384 | 1000 | apache-2.0 | timm |
resnetv2_152x4_bit.goog_in21k | 224 | - | - | 21843 | apache-2.0 | timm |
resnetv2_152x4_bit.goog_in21k_ft_in1k | 480 | 84.936 | 480 | 1000 | apache-2.0 | timm |
ra4 tags
| Weight | Input size | Top-1 (%) | Eval size | Classes | License | Hub |
|---|---|---|---|---|---|---|
resnetv2_18.ra4_e3600_r224_in1k | 224 (test 288) | 75.364 | 288 | 1000 | apache-2.0 | timm |
resnetv2_18d.ra4_e3600_r224_in1k | 224 (test 288) | 76.058 | 288 | 1000 | apache-2.0 | timm |
resnetv2_34.ra4_e3600_r224_in1k | 224 (test 288) | 79.070 | 288 | 1000 | apache-2.0 | timm |
resnetv2_34d.ra4_e3600_r224_in1k | 224 (test 288) | 79.614 | 288 | 1000 | apache-2.0 | timm |
resnetv2_34d.ra4_e3600_r384_in1k | 384 (test 448) | 80.430 | 448 | 1000 | apache-2.0 | timm |
a1h tags
| Weight | Input size | Top-1 (%) | Eval size | Classes | License | Hub |
|---|---|---|---|---|---|---|
resnetv2_50.a1h_in1k | 224 (test 288) | 81.406 | 288 | 1000 | apache-2.0 | timm |
resnetv2_101.a1h_in1k | 224 (test 288) | 83.002 | 288 | 1000 | apache-2.0 | timm |
ah tags
| Weight | Input size | Top-1 (%) | Eval size | Classes | License | Hub |
|---|---|---|---|---|---|---|
resnetv2_50d_evos.ah_in1k | 224 (test 288) | 82.024 | 288 | 1000 | apache-2.0 | timm |
resnetv2_50d_gn.ah_in1k | 224 (test 288) | 81.960 | 288 | 1000 | apache-2.0 | timm |