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Deep Residual Networks (ResNet) ImageNet Classification


Classifies images into 1,000 ImageNet categories using residual learning with skip connections. Three variants available: ResNet-18 (69.57% top-1), ResNet-50 (75.99% top-1), ResNet-101 (77.56% top-1). Trade-off accuracy for speed/parameters.

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What it does

ResNet classifies images into 1,000 ImageNet categories using residual learning (skip connections). Architecture enables training of very deep networks (18–101 layers) without vanishing gradient problems. Three model sizes available for different accuracy/efficiency requirements.

Problem it solves

Input/Output

Input: RGB image

Input: RGB image

Output: Logits for 1,000 ImageNet classes

Output: Logits for 1,000 ImageNet classes

Accuracy & Speed

Model Top-1 Accuracy Top-5 Accuracy Parameters
ResNet-18 69.57% 89.24% 11.7M
ResNet-50 75.99% 92.98% 25.6M
ResNet-101 77.56% 93.79% 44.5M

Best For:

Technical Details

Architecture Residual Learning with Skip Connections
Core Innovation: y = F(x) + x • F(x): Residual function learned by stacked layers
• x: Skip connection (identity bypass)
• Benefits: Enables gradient flow through deep networks, mitigates vanishing gradient
Building block • ResNet-18: Basic blocks (2 conv layers per block)
• ResNet-50/101: Bottleneck blocks (1×1 reduce → 3×3 → 1×1 restore)
Training • Dataset: ImageNet-1k (1.28M training images, 1,000 classes)
• Optimizer: SGD (momentum 0.9)
• Batch size: 256
• Learning rate: 0.1 (÷10 every 30 epochs)
• Epochs: 100
• Weight decay: 1e-4
• Data augmentation:
◦ Random crop 224×224
â—¦ Random horizontal flip
◦ Multi-scale jitter (256–480)
â—¦ ImageNet normalization (per-channel mean/std) |

| Depth Per Stage | • ResNet-18: [2, 2, 2, 2] • ResNet-50: [3, 4, 6, 3] • ResNet-101: [3, 4, 23, 3] |

Compliance & Provenance