Method Details
Details for method 'Fast-SCNN (Quarter-resolution)'
Method overview
| name | Fast-SCNN (Quarter-resolution) |
| challenge | pixel-level semantic labeling |
| details | The encoder-decoder framework is state-of-the-art for offline semantic image segmentation. Since the rise in autonomous systems, real-time computation is increasingly desirable. In this paper, we introduce fast segmentation convolutional neural network (Fast-SCNN), an above real-time semantic segmentation model on high resolution image data (1024x2048px) suited to efficient computation on embedded devices with low memory. Building on existing two-branch methods for fast segmentation, we introduce our `learning to downsample' module which computes low-level features for multiple resolution branches simultaneously. Our network combines spatial detail at high resolution with deep features extracted at lower resolution, yielding an accuracy of 68.0% mean intersection over union at 123.5 frames per second on Cityscapes. We also show that large scale pre-training is unnecessary. We thoroughly validate our metric in experiments with ImageNet pre-training and the coarse labeled data of Cityscapes. Finally, we show even faster computation with competitive results on subsampled inputs, without any network modifications. |
| publication | Fast-SCNN: Fast Semantic Segmentation Network Rudra P K Poudel, Stephan Liwicki, Roberto Cipolla https://arxiv.org/abs/1902.04502 |
| project page / code | |
| used Cityscapes data | fine annotations |
| used external data | |
| runtime | 0.00206 s Nvidia Titan Xp (Pascal) |
| subsampling | 4 |
| submission date | November, 2018 |
| previous submissions |
Average results
| Metric | Value |
|---|---|
| IoU Classes | 51.9292 |
| iIoU Classes | 23.0119 |
| IoU Categories | 74.1649 |
| iIoU Categories | 48.2369 |
Class results
| Class | IoU | iIoU |
|---|---|---|
| road | 96.3406 | - |
| sidewalk | 70.4595 | - |
| building | 83.1103 | - |
| wall | 26.0995 | - |
| fence | 23.5008 | - |
| pole | 18.6551 | - |
| traffic light | 26.1479 | - |
| traffic sign | 33.1417 | - |
| vegetation | 84.504 | - |
| terrain | 55.7191 | - |
| sky | 89.5119 | - |
| person | 55.1668 | 28.1508 |
| rider | 35.4404 | 10.2066 |
| car | 86.8067 | 70.7005 |
| truck | 38.7097 | 10.3824 |
| bus | 47.386 | 18.0632 |
| train | 46.683 | 18.1863 |
| motorcycle | 27.2933 | 6.94711 |
| bicycle | 41.9791 | 21.4585 |
Category results
| Category | IoU | iIoU |
|---|---|---|
| flat | 96.7545 | - |
| nature | 83.8904 | - |
| object | 25.4159 | - |
| sky | 89.5119 | - |
| construction | 82.8695 | - |
| human | 55.6375 | 28.7441 |
| vehicle | 85.0747 | 67.7297 |