mmcv.ops.deform_roi_pool 源代码

# Copyright (c) OpenMMLab. All rights reserved.
from torch import nn
from torch.autograd import Function
from torch.autograd.function import once_differentiable
from torch.nn.modules.utils import _pair

from ..utils import ext_loader

ext_module = ext_loader.load_ext(
    '_ext', ['deform_roi_pool_forward', 'deform_roi_pool_backward'])


class DeformRoIPoolFunction(Function):

    @staticmethod
    def symbolic(g, input, rois, offset, output_size, spatial_scale,
                 sampling_ratio, gamma):
        return g.op(
            'mmcv::MMCVDeformRoIPool',
            input,
            rois,
            offset,
            pooled_height_i=output_size[0],
            pooled_width_i=output_size[1],
            spatial_scale_f=spatial_scale,
            sampling_ratio_f=sampling_ratio,
            gamma_f=gamma)

    @staticmethod
    def forward(ctx,
                input,
                rois,
                offset,
                output_size,
                spatial_scale=1.0,
                sampling_ratio=0,
                gamma=0.1):
        if offset is None:
            offset = input.new_zeros(0)
        ctx.output_size = _pair(output_size)
        ctx.spatial_scale = float(spatial_scale)
        ctx.sampling_ratio = int(sampling_ratio)
        ctx.gamma = float(gamma)

        assert rois.size(1) == 5, 'RoI must be (idx, x1, y1, x2, y2)!'

        output_shape = (rois.size(0), input.size(1), ctx.output_size[0],
                        ctx.output_size[1])
        output = input.new_zeros(output_shape)

        ext_module.deform_roi_pool_forward(
            input,
            rois,
            offset,
            output,
            pooled_height=ctx.output_size[0],
            pooled_width=ctx.output_size[1],
            spatial_scale=ctx.spatial_scale,
            sampling_ratio=ctx.sampling_ratio,
            gamma=ctx.gamma)

        ctx.save_for_backward(input, rois, offset)
        return output

    @staticmethod
    @once_differentiable
    def backward(ctx, grad_output):
        input, rois, offset = ctx.saved_tensors
        grad_input = grad_output.new_zeros(input.shape)
        grad_offset = grad_output.new_zeros(offset.shape)

        ext_module.deform_roi_pool_backward(
            grad_output,
            input,
            rois,
            offset,
            grad_input,
            grad_offset,
            pooled_height=ctx.output_size[0],
            pooled_width=ctx.output_size[1],
            spatial_scale=ctx.spatial_scale,
            sampling_ratio=ctx.sampling_ratio,
            gamma=ctx.gamma)
        if grad_offset.numel() == 0:
            grad_offset = None
        return grad_input, None, grad_offset, None, None, None, None


deform_roi_pool = DeformRoIPoolFunction.apply


[文档]class DeformRoIPool(nn.Module): def __init__(self, output_size, spatial_scale=1.0, sampling_ratio=0, gamma=0.1): super(DeformRoIPool, self).__init__() self.output_size = _pair(output_size) self.spatial_scale = float(spatial_scale) self.sampling_ratio = int(sampling_ratio) self.gamma = float(gamma)
[文档] def forward(self, input, rois, offset=None): return deform_roi_pool(input, rois, offset, self.output_size, self.spatial_scale, self.sampling_ratio, self.gamma)
[文档]class DeformRoIPoolPack(DeformRoIPool): def __init__(self, output_size, output_channels, deform_fc_channels=1024, spatial_scale=1.0, sampling_ratio=0, gamma=0.1): super(DeformRoIPoolPack, self).__init__(output_size, spatial_scale, sampling_ratio, gamma) self.output_channels = output_channels self.deform_fc_channels = deform_fc_channels self.offset_fc = nn.Sequential( nn.Linear( self.output_size[0] * self.output_size[1] * self.output_channels, self.deform_fc_channels), nn.ReLU(inplace=True), nn.Linear(self.deform_fc_channels, self.deform_fc_channels), nn.ReLU(inplace=True), nn.Linear(self.deform_fc_channels, self.output_size[0] * self.output_size[1] * 2)) self.offset_fc[-1].weight.data.zero_() self.offset_fc[-1].bias.data.zero_()
[文档] def forward(self, input, rois): assert input.size(1) == self.output_channels x = deform_roi_pool(input, rois, None, self.output_size, self.spatial_scale, self.sampling_ratio, self.gamma) rois_num = rois.size(0) offset = self.offset_fc(x.view(rois_num, -1)) offset = offset.view(rois_num, 2, self.output_size[0], self.output_size[1]) return deform_roi_pool(input, rois, offset, self.output_size, self.spatial_scale, self.sampling_ratio, self.gamma)
[文档]class ModulatedDeformRoIPoolPack(DeformRoIPool): def __init__(self, output_size, output_channels, deform_fc_channels=1024, spatial_scale=1.0, sampling_ratio=0, gamma=0.1): super(ModulatedDeformRoIPoolPack, self).__init__(output_size, spatial_scale, sampling_ratio, gamma) self.output_channels = output_channels self.deform_fc_channels = deform_fc_channels self.offset_fc = nn.Sequential( nn.Linear( self.output_size[0] * self.output_size[1] * self.output_channels, self.deform_fc_channels), nn.ReLU(inplace=True), nn.Linear(self.deform_fc_channels, self.deform_fc_channels), nn.ReLU(inplace=True), nn.Linear(self.deform_fc_channels, self.output_size[0] * self.output_size[1] * 2)) self.offset_fc[-1].weight.data.zero_() self.offset_fc[-1].bias.data.zero_() self.mask_fc = nn.Sequential( nn.Linear( self.output_size[0] * self.output_size[1] * self.output_channels, self.deform_fc_channels), nn.ReLU(inplace=True), nn.Linear(self.deform_fc_channels, self.output_size[0] * self.output_size[1] * 1), nn.Sigmoid()) self.mask_fc[2].weight.data.zero_() self.mask_fc[2].bias.data.zero_()
[文档] def forward(self, input, rois): assert input.size(1) == self.output_channels x = deform_roi_pool(input, rois, None, self.output_size, self.spatial_scale, self.sampling_ratio, self.gamma) rois_num = rois.size(0) offset = self.offset_fc(x.view(rois_num, -1)) offset = offset.view(rois_num, 2, self.output_size[0], self.output_size[1]) mask = self.mask_fc(x.view(rois_num, -1)) mask = mask.view(rois_num, 1, self.output_size[0], self.output_size[1]) d = deform_roi_pool(input, rois, offset, self.output_size, self.spatial_scale, self.sampling_ratio, self.gamma) return d * mask