/pytorch-deform-conv-v2

PyTorch implementation of Deformable ConvNets v2 (Modulated Deformable Convolution)

Primary LanguagePythonMIT LicenseMIT

PyTorch implementation of Deformable ConvNets v2

This repository contains code for Deformable ConvNets v2 (Modulated Deformable Convolution) based on Deformable ConvNets v2: More Deformable, Better Results implemented in PyTorch. This implementation of deformable convolution based on ChunhuanLin/deform_conv_pytorch, thanks to ChunhuanLin.

TODO

  • Initialize weight of modulated deformable convolution based on paper
  • Learning rates of offset and modulation are set to different values from other layers
  • Results of ScaledMNIST experiments
  • Support different stride
  • Support deformable group
  • DeepLab + DCNv2
  • Results of VOC segmentation experiments

Requirements

  • Python 3.6
  • PyTorch 1.0

Usage

Replace regular convolution (following model's conv2) with modulated deformable convolution:

class ConvNet(nn.Module):
  def __init__(self):
    self.relu = nn.ReLU(inplace=True)
    self.pool = nn.MaxPool2d((2, 2))
    self.avg_pool = nn.AdaptiveAvgPool2d(1)

    self.conv1 = nn.Conv2d(3, 32, 3, padding=1)
    self.bn1 = nn.BatchNorm2d(32)
    self.conv2 = nn.DeformConv2d(32, 64, 3, padding=1, modulation=True)
    self.bn2 = nn.BatchNorm2d(64)

    self.fc = nn.Linear(64, 10)

  def forward(self, x):
    x = self.relu(self.bn1(self.conv1(x)))
    x = self.pool(x)
    x = self.relu(self.bn2(self.conv2(x)))

    x = self.avg_pool(x)
    x = x.view(x.shape[0], -1)
    x = self.fc(x)

    return x

Training

ScaledMNIST

ScaledMNIST is randomly scaled MNIST.

Use modulated deformable convolution at conv3~4:

python train.py --arch ScaledMNISTNet --deform True --modulation True --min-deform-layer 3

Use deformable convolution at conv3~4:

python train.py --arch ScaledMNISTNet --deform True --modulation False --min-deform-layer 3

Use only regular convolution:

python train.py --arch ScaledMNISTNet --deform False --modulation False

Results

ScaledMNIST

Model Accuracy (%) Loss
w/o DCN 97.22 0.113
w/ DCN @conv4 98.60 0.049
w/ DCN @conv3~4 98.95 0.035
w/ DCNv2 @conv4 98.45 0.058
w/ DCNv2 @conv3~4 99.21 0.027