Spaces:
Build error
Build error
from torch import nn | |
import torch | |
import torch.nn.functional as F | |
from modules.util import Hourglass, make_coordinate_grid, AntiAliasInterpolation2d | |
class KPDetector(nn.Module): | |
""" | |
Detecting a keypoints. Return keypoint position and jacobian near each keypoint. | |
""" | |
def __init__(self, block_expansion, num_kp, num_channels, max_features, | |
num_blocks, temperature, estimate_jacobian=False, scale_factor=1, | |
single_jacobian_map=False, pad=0): | |
super(KPDetector, self).__init__() | |
self.predictor = Hourglass(block_expansion, in_features=num_channels, | |
max_features=max_features, num_blocks=num_blocks) | |
self.kp = nn.Conv2d(in_channels=self.predictor.out_filters, out_channels=num_kp, kernel_size=(7, 7), | |
padding=pad) | |
if estimate_jacobian: | |
self.num_jacobian_maps = 1 if single_jacobian_map else num_kp | |
self.jacobian = nn.Conv2d(in_channels=self.predictor.out_filters, | |
out_channels=4 * self.num_jacobian_maps, kernel_size=(7, 7), padding=pad) | |
self.jacobian.weight.data.zero_() | |
self.jacobian.bias.data.copy_(torch.tensor([1, 0, 0, 1] * self.num_jacobian_maps, dtype=torch.float)) | |
else: | |
self.jacobian = None | |
self.temperature = temperature | |
self.scale_factor = scale_factor | |
if self.scale_factor != 1: | |
self.down = AntiAliasInterpolation2d(num_channels, self.scale_factor) | |
def gaussian2kp(self, heatmap): | |
""" | |
Extract the mean and from a heatmap | |
""" | |
shape = heatmap.shape | |
heatmap = heatmap.unsqueeze(-1) | |
grid = make_coordinate_grid(shape[2:], heatmap.type()).unsqueeze_(0).unsqueeze_(0) | |
value = (heatmap * grid).sum(dim=(2, 3)) | |
kp = {'value': value} | |
return kp | |
def forward(self, x): | |
if self.scale_factor != 1: | |
x = self.down(x) | |
feature_map = self.predictor(x) | |
prediction = self.kp(feature_map) | |
final_shape = prediction.shape | |
heatmap = prediction.view(final_shape[0], final_shape[1], -1) | |
heatmap = F.softmax(heatmap / self.temperature, dim=2) | |
heatmap = heatmap.view(*final_shape) | |
out = self.gaussian2kp(heatmap) | |
if self.jacobian is not None: | |
jacobian_map = self.jacobian(feature_map) | |
jacobian_map = jacobian_map.reshape(final_shape[0], self.num_jacobian_maps, 4, final_shape[2], | |
final_shape[3]) | |
heatmap = heatmap.unsqueeze(2) | |
jacobian = heatmap * jacobian_map | |
jacobian = jacobian.view(final_shape[0], final_shape[1], 4, -1) | |
jacobian = jacobian.sum(dim=-1) | |
jacobian = jacobian.view(jacobian.shape[0], jacobian.shape[1], 2, 2) | |
out['jacobian'] = jacobian | |
return out | |