Pyramid Stereo Matching Network

This repository contains the code (in PyTorch) for "Pyramid Stereo Matching Network" paper (CVPR 2018) by Jia-Ren Chang and Yong-Sheng Chen.

Citation

@inproceedings{chang2018pyramid,
  title={Pyramid Stereo Matching Network},
  author={Chang, Jia-Ren and Chen, Yong-Sheng},
  booktitle={Proceedings of the IEEE Conference on Computer Vision and Pattern Recognition},
  pages={5410--5418},
  year={2018}
}

Contents

1. Introduction
2. Usage
3. Results
4. Contacts

Introduction

Recent work has shown that depth estimation from a stereo pair of images can be formulated as a supervised learning task to be resolved with convolutional neural networks (CNNs). However, current architectures rely on patch-based Siamese networks, lacking the means to exploit context information for finding correspondence in illposed regions. To tackle this problem, we propose PSMNet, a pyramid stereo matching network consisting of two main modules: spatial pyramid pooling and 3D CNN. The spatial pyramid pooling module takes advantage of the capacity of global context information by aggregating context in different scales and locations to form a cost volume. The 3D CNN learns to regularize cost volume using stacked multiple hourglass networks in conjunction with intermediate supervision.

Usage

Dependencies

• Python2.7
• PyTorch(0.4.0+)
• torchvision 0.2.0 (higher version may cause issues)
• KITTI Stereo
• Scene Flow

Usage of Scene Flow dataset
Download RGB cleanpass images and its disparity for three subset: FlyingThings3D, Driving, and Monkaa.
Put them in the same folder.
And rename the folder as: "driving_frames_cleanpass", "driving_disparity", "monkaa_frames_cleanpass", "monkaa_disparity", "frames_cleanpass", "frames_disparity".

Train

As an example, use the following command to train a PSMNet on Scene Flow

python main.py --maxdisp 192 \
               --model stackhourglass \
               --datapath (your scene flow data folder)\
               --epochs 10 \
               --loadmodel (optional)\
               --savemodel (path for saving model)

As another example, use the following command to finetune a PSMNet on KITTI 2015

python finetune.py --maxdisp 192 \
                   --model stackhourglass \
                   --datatype 2015 \
                   --datapath (KITTI 2015 training data folder) \
                   --epochs 300 \
                   --loadmodel (pretrained PSMNet) \
                   --savemodel (path for saving model)

You can also see those examples in run.sh.

Evaluation

Use the following command to evaluate the trained PSMNet on KITTI 2015 test data

python submission.py --maxdisp 192 \
                     --model stackhourglass \
                     --KITTI 2015 \
                     --datapath (KITTI 2015 test data folder) \
                     --loadmodel (finetuned PSMNet) \

Pretrained Model

※NOTE: The pretrained model were saved in .tar; however, you don't need to untar it. Use torch.load() to load it.

Update: 2018/9/6 We released the pre-trained KITTI 2012 model.

KITTI 2015	Scene Flow	KITTI 2012
Google Drive	Google Drive	Google Drive

Results

Evaluation of PSMNet with different settings

※Note that the reported 3-px validation errors were calculated using KITTI's official matlab code, not our code.

Results on KITTI 2015 leaderboard

Leaderboard Link

Method	D1-all (All)	D1-all (Noc)	Runtime (s)
PSMNet	2.32 %	2.14 %	0.41
iResNet-i2	2.44 %	2.19 %	0.12
GC-Net	2.87 %	2.61 %	0.90
MC-CNN	3.89 %	3.33 %	67

Qualitative results

Left image

Predicted disparity

Error

Visualization of Receptive Field

We visualize the receptive fields of different settings of PSMNet, full setting and baseline.

Full setting: dilated conv, SPP, stacked hourglass

Baseline: no dilated conv, no SPP, no stacked hourglass

The receptive fields were calculated for the pixel at image center, indicated by the red cross.

Contacts

[email protected]

Any discussions or concerns are welcomed!