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ResNet

The ResNet features are extracted at each frame of the provided video. The ResNet is pre-trained on the 1k ImageNet dataset. We extract features from the pre-classification layer. The implementation is based on the torchvision models. The extracted features are going to be of size num_frames x 2048. We additionally output timesteps in ms for each feature and fps of the video. We use the standard set of augmentations.

Set up the Environment for ResNet

Setup conda environment. Requirements are in file conda_env_torch_zoo.yml

# it will create a new conda environment called 'torch_zoo' on your machine
conda env create -f conda_env_torch_zoo.yml

Minimal Working Example

Open In Colab

Activate the environment

conda activate torch_zoo

and extract features at 1 fps from ./sample/v_GGSY1Qvo990.mp4 video and show the predicted classes

python main.py \
    feature_type=resnet101 \
    extraction_fps=1 \
    video_paths="[./sample/v_GGSY1Qvo990.mp4]" \
    show_pred=true

Examples

Start by activating the environment

conda activate torch_zoo

It is pretty much the same procedure as with other features. The example is provided for the ResNet-50 flavour, but we also support ResNet-18,34,101,152.

python main.py \
    feature_type=resnet50 \
    device_ids="[0, 2]" \
    video_paths="[./sample/v_ZNVhz7ctTq0.mp4, ./sample/v_GGSY1Qvo990.mp4]"

If you would like to save the features, use --on_extraction save_numpy (or save_pickle) – by default, the features are saved in ./output/ or where --output_path specifies. In the case of frame-wise features, besides features, it also saves timestamps in ms and the original fps of the video into the same folder with features.

python main.py \
    feature_type=resnet50 \
    device_ids="[0, 2]" \
    on_extraction=save_numpy \
    file_with_video_paths=./sample/sample_video_paths.txt

Since these features are so fine-grained and light-weight we may increase the extraction speed with batching. Therefore, frame-wise features have --batch_size argument, which defaults to 1.

python main.py \
    feature_type=resnet50 \
    device_ids="[0, 2]" \
    batch_size=128 \
    video_paths="[./sample/v_ZNVhz7ctTq0.mp4, ./sample/v_GGSY1Qvo990.mp4]"

If you would like to extract features at a certain fps, add --extraction_fps argument

python main.py \
    feature_type=resnet50 \
    device_ids="[0, 2]" \
    extraction_fps=5 \
    video_paths="[./sample/v_ZNVhz7ctTq0.mp4, ./sample/v_GGSY1Qvo990.mp4]"

Credits

  1. The TorchVision implementation.
  2. The ResNet paper

License

The wrapping code is under MIT, yet, it utilizes torchvision library which is under BSD 3-Clause "New" or "Revised" License.