Table 2.
Enhanced DenseNet169 model structure for skin cancer image analysis.
| Stage | Original layer | Enhanced layer | Modification | Parameters (Enhanced) |
|---|---|---|---|---|
| Input | 224 × 224 × 3 | 224 × 224 × 3 | No change | – |
| Initial convolution | 7 × 7 conv, 64 filters, stride 2 | 3 × 3 conv, 32 filters, stride 2 | Reduced filter size & number | ~ 0.9 M |
| Pooling | 3 × 3 max pool, stride 2 | 3 × 3 max pool, stride 2 | No change | – |
| Dense block 1 | 6 convolutional layers | 6 convolutional layers | Retained | ~ 1.6 M |
| Transition layer 1 | 1 × 1 conv + 2 × 2 avg pool | 1 × 1 conv + 2 × 2 avg pool | Retained | ~ 0.2 M |
| Dense block 2 | 12 convolutional layers | 12 convolutional layers | Retained | ~ 3.2 M |
| Transition layer 2 | 1 × 1 conv + 2 × 2 avg pool | 1 × 1 conv + 2 × 2 avg pool | Retained | ~ 0.3 M |
| Dense block 3 | 32 convolutional layers | 16 convolutional layers | Reduced by 50% (less deep features) | ~ 1.9 M |
| Transition layer 3 | 1 × 1 conv + 2 × 2 avg pool | 1 × 1 conv + 2 × 2 avg pool | Retained | ~ 0.2 M |
| Dense block 4 | 32 convolutional layers | Removed | Significant reduction in computation | 0 |
| Final output | Feature vector from final transition layer | Feature vector from final transition layer | Used as input to external classifier | – |
| Total parameters | ≈ 14.3 million | – | ~ 50% Reduction | ~ 7.35 M |