RE-OWOD/projects/DensePose/densepose/data/samplers/densepose_base.py

191 lines
7.0 KiB
Python

# Copyright (c) Facebook, Inc. and its affiliates. All Rights Reserved
from typing import List, Optional
import torch
from torch.nn import functional as F
from detectron2.structures import BoxMode, Instances
from ..structures import (
DensePoseDataRelative,
DensePoseList,
DensePoseOutput,
resample_output_to_bbox,
)
class DensePoseBaseSampler:
"""
Base DensePose sampler to produce DensePose data from DensePose predictions.
Samples for each class are drawn according to some distribution over all pixels estimated
to belong to that class.
"""
def __init__(self, count_per_class: int = 8):
"""
Constructor
Args:
count_per_class (int): the sampler produces at most `count_per_class`
samples for each category
"""
self.count_per_class = count_per_class
def __call__(self, instances: Instances) -> DensePoseList:
"""
Convert DensePose predictions (an instance of `DensePoseOutput`)
into DensePose annotations data (an instance of `DensePoseList`)
"""
boxes_xyxy_abs = instances.pred_boxes.tensor.clone().cpu()
boxes_xywh_abs = BoxMode.convert(boxes_xyxy_abs, BoxMode.XYXY_ABS, BoxMode.XYWH_ABS)
dp_datas = []
for i, box_xywh in enumerate(boxes_xywh_abs):
labels_i, result_i = resample_output_to_bbox(
instances.pred_densepose[i], box_xywh, self._confidence_channels()
)
annotation_i = self._sample(labels_i.cpu(), result_i.cpu(), box_xywh)
annotation_i[DensePoseDataRelative.S_KEY] = self._resample_mask(
instances.pred_densepose[i]
)
dp_datas.append(DensePoseDataRelative(annotation_i))
# create densepose annotations on CPU
dp_list = DensePoseList(dp_datas, boxes_xyxy_abs, instances.image_size)
return dp_list
def _sample(
self, labels: torch.Tensor, dp_result: torch.Tensor, bbox_xywh: List[int]
) -> DensePoseDataRelative:
"""
Sample DensPoseDataRelative from estimation results
"""
annotation = {
DensePoseDataRelative.X_KEY: [],
DensePoseDataRelative.Y_KEY: [],
DensePoseDataRelative.U_KEY: [],
DensePoseDataRelative.V_KEY: [],
DensePoseDataRelative.I_KEY: [],
}
x0, y0, _, _ = bbox_xywh
n, h, w = dp_result.shape
for part_id in range(1, DensePoseDataRelative.N_PART_LABELS + 1):
# indices - tuple of 3 1D tensors of size k
# 0: index along the first dimension N
# 1: index along H dimension
# 2: index along W dimension
indices = torch.nonzero(labels.expand(n, h, w) == part_id, as_tuple=True)
# values - an array of size [n, k]
# n: number of channels (U, V, confidences)
# k: number of points labeled with part_id
values = dp_result[indices].view(n, -1)
k = values.shape[1]
count = min(self.count_per_class, k)
if count <= 0:
continue
index_sample = self._produce_index_sample(values, count)
sampled_values = values[:, index_sample]
sampled_y = indices[1][index_sample] + 0.5
sampled_x = indices[2][index_sample] + 0.5
# prepare / normalize data
x = (sampled_x / w * 256.0).cpu().tolist()
y = (sampled_y / h * 256.0).cpu().tolist()
u = sampled_values[0].clamp(0, 1).cpu().tolist()
v = sampled_values[1].clamp(0, 1).cpu().tolist()
fine_segm_labels = [part_id] * count
# extend annotations
annotation[DensePoseDataRelative.X_KEY].extend(x)
annotation[DensePoseDataRelative.Y_KEY].extend(y)
annotation[DensePoseDataRelative.U_KEY].extend(u)
annotation[DensePoseDataRelative.V_KEY].extend(v)
annotation[DensePoseDataRelative.I_KEY].extend(fine_segm_labels)
return annotation
def _confidence_channels(self) -> Optional[List[str]]:
"""
Confedence channels to be used for sampling (to be overridden in children)
"""
return None
def _produce_index_sample(self, values: torch.Tensor, count: int):
"""
Abstract method to produce a sample of indices to select data
To be implemented in descendants
Args:
values (torch.Tensor): an array of size [n, k] that contains
estimated values (U, V, confidences);
n: number of channels (U, V, confidences)
k: number of points labeled with part_id
count (int): number of samples to produce, should be positive and <= k
:w
Return:
list(int): indices of values (along axis 1) selected as a sample
"""
raise NotImplementedError
def _resample_mask(self, output: DensePoseOutput) -> torch.Tensor:
"""
Convert output mask tensors into the annotation mask tensor of size
(256, 256)
"""
sz = DensePoseDataRelative.MASK_SIZE
S = (
F.interpolate(output.S, (sz, sz), mode="bilinear", align_corners=False)
.argmax(dim=1)
.long()
)
I = (
(
F.interpolate(output.I, (sz, sz), mode="bilinear", align_corners=False).argmax(
dim=1
)
* (S > 0).long()
)
.squeeze()
.cpu()
)
# Map fine segmentation results to coarse segmentation ground truth
# TODO: extract this into separate classes
# coarse segmentation: 1 = Torso, 2 = Right Hand, 3 = Left Hand,
# 4 = Left Foot, 5 = Right Foot, 6 = Upper Leg Right, 7 = Upper Leg Left,
# 8 = Lower Leg Right, 9 = Lower Leg Left, 10 = Upper Arm Left,
# 11 = Upper Arm Right, 12 = Lower Arm Left, 13 = Lower Arm Right,
# 14 = Head
# fine segmentation: 1, 2 = Torso, 3 = Right Hand, 4 = Left Hand,
# 5 = Left Foot, 6 = Right Foot, 7, 9 = Upper Leg Right,
# 8, 10 = Upper Leg Left, 11, 13 = Lower Leg Right,
# 12, 14 = Lower Leg Left, 15, 17 = Upper Arm Left,
# 16, 18 = Upper Arm Right, 19, 21 = Lower Arm Left,
# 20, 22 = Lower Arm Right, 23, 24 = Head
FINE_TO_COARSE_SEGMENTATION = {
1: 1,
2: 1,
3: 2,
4: 3,
5: 4,
6: 5,
7: 6,
8: 7,
9: 6,
10: 7,
11: 8,
12: 9,
13: 8,
14: 9,
15: 10,
16: 11,
17: 10,
18: 11,
19: 12,
20: 13,
21: 12,
22: 13,
23: 14,
24: 14,
}
mask = torch.zeros((sz, sz), dtype=torch.int64, device=torch.device("cpu"))
for i in range(DensePoseDataRelative.N_PART_LABELS):
mask[I == i + 1] = FINE_TO_COARSE_SEGMENTATION[i + 1]
return mask