Scene Consistency Representation Learning for Video Scene Segmentation (CVPR2022)

This is an official PyTorch implementation of SCRL, the CVPR2022 paper is available at here.

Getting Started

Data Preparation

MovieNet Dataset

Download MovieNet Dataset from its Official Website.

SceneSeg318 Dataset

Download the Annotation of SceneSeg318, you can find the download instructions in LGSS repository.

Make Puzzles for pre-training

In order to reduce the number of IO accesses and perform data augmentation (a.k.a Scene Agnostic Clip-Shuffling in the paper) at the same time, we suggest to stitch 16 shots into one image (puzzle) during the pre-training stage. You can make the data by yourself:

python ./data/data_preparation.py

And the processed data will be saved in ./compressed_shot_images/, a puzzle example figure.

Load the Data into Memory [Optional]

We strongly recommend loading data into memory to speed up pre-training, which additionally requires your device to have at least 100GB of RAM.

mkdir /tmpdata
mount tmpfs /tmpdata -t tmpfs -o size=100G
cp -r ./compressed_shot_images/ /tmpdata/

Initialization Weights Preparation

Download the ResNet-50 weights trained on ImageNet-1k (resnet50-19c8e357.pth), and save it in ./pretrain/ folder.

Prerequisites

Requirements

• python >= 3.6
• pytorch >= 1.6
• cv2
• pickle
• numpy
• yaml
• sklearn

Hardware

• 8 NVIDIA V100 (32GB) GPUs

Usage

STEP 1: Encoder Pre-training

Using the default configuration to pretrain the model. Make sure the data path is correct and the GPUs are sufficient (e.g. 8 NVIDIA V100 GPUs)

python pretrain_main.py --config ./config/SCRL_pretrain_default.yaml

The checkpoint, copy of config and log will be saved in ./output/.

STEP 2: Feature Extraction

python extract_embeddings.py $CKP_PATH --shot_img_path $SHOT_PATH --Type all --gpu-id 0

$CKP_PATH is the path of an encoder checkpoint, and $SHOT_PATH is the keyframe path of MovieNet. The extracted embeddings (in pickle format) and log will be saved in ./embeddings/.

STEP 3: Video Scene Segmentation Evaluation

cd SceneSeg

python main.py \
    -train $TRAIN_PKL_PATH \
    -test  $TEST_PKL_PATH \
    -val   $VAL_PKL_PATH \
    --seq-len 40 \
    --gpu-id 0

The checkpoints and log will be saved in ./SceneSeg/output/.

Models

We provide checkpoints, logs and results under two different pre-training settings, i.e. with and without ImageNet-1K initialization, respectively.

Initialization	AP	F1	Config File	STEP 1 Pre-training	STEP 2 Embeddings	STEP 3 Fine-tuning
w/o ImageNet-1k	55.16	51.32	SCRL_pretrain _without_imagenet1k.yaml	ckp and log	embedings	ckps and log
w/ ImageNet-1k	56.65	52.45	SCRL_pretrain _with_imagenet1k.yaml	ckp and log	embedings	ckps and log

License

Please see LICENSE file for the details.

Acknowledgments

Part of codes are borrowed from the following repositories:

• MoCo
• LGSS

Citation

Please cite our work if it's useful for your research.

@InProceedings{Wu_2022_CVPR,
    author    = {Wu, Haoqian and Chen, Keyu and Luo, Yanan and Qiao, Ruizhi and Ren, Bo and Liu, Haozhe and Xie, Weicheng and Shen, Linlin},
    title     = {Scene Consistency Representation Learning for Video Scene Segmentation},
    booktitle = {Proceedings of the IEEE/CVF Conference on Computer Vision and Pattern Recognition (CVPR)},
    month     = {June},
    year      = {2022},
    pages     = {14021-14030}
}