PiX: Dynamic Channel Sampling for ConvNets

Official PyTorch implementation of PiX in CVPR 2024, from the following paper:
PiX: Dynamic Channel Sampling for ConvNets
Ashish Kumar, Daneul Kim, Jaesik Park, Laxmidhar Behera

PiX namely Pick-or-Mix (PiX) is an effective multi-purpose module for dynamic channel sampling. PiX divides a set of channels into subsets and then picks from them, where the picking decision is dynamically made per each pixel based on the input activations. PiX can perform fast channel squeezing, network downscaling and also can behave as dynamic channel prunner. In channel squezing mode, after replacing 1 × 1 channel squeezing layers in ResNet with PiX, the network becomes 25% faster without losing accuracy.

PiX in Fast Channel Squeezing Mode

Installation

The results are produced with torch==1.11.0 and timm 0.9.2. Other versions might also work.

Dataset Preparation

Download the ImageNet-1K classification dataset and structure the data as follows:

/path/to/imagenet-1k/
  train/
    class1/
      img1.jpeg
    class2/
      img2.jpeg
  val/
    class1/
      img3.jpeg
    class2/
      img4.jpeg

Checkpoint

Download the pre-trained checkpoint from here

Training

Before Training PiX pytorch cuda plugin must be built. Follow the steps below:

cd models/layers
python setup.py install

Now, you can use the following command to train PiX ResNet-50 on a single 8-GPU machine:

python -m torch.distributed.launch --nproc_per_node=8 \
main.py --model PiXResNet50_cs \
--data_path path_to_imagenet \
--lr 3.5e-3 --weight_decay 0.35  --drop 0.05 \
--opt lamb --aa rand-m7-mstd0.5-inc1 --mixup 0.15 --bce_loss
--output_dir /dir_for_saving_models \
--model_ema true --model_ema_eval true --model_ema_decay 0.99996 
--batch_size 128 

• Effective batch size = --nproc_per_node * --batch_size * --update_freq.

Acknowledgement

This repository is built using the timm library, VanillaNet repositories.

Citation

If our work is useful for your research, please consider citing:

@article{pix,
  title={Pick-or-Mix: Dynamic Channel Sampling for ConvNets},
  author={Kumar, Ashish and Kim, Daneul and Park, Jaesik and Behera, Laxmidhar},
  journal={Computer Vision and Pattern Recognition},
  year={2024}
}