wizzseen's picture
Upload 948 files
8a6df40 verified
from posenet.decode import *
from posenet.constants import *
import torch
import torch.nn as nn
import torch.nn.functional as F
def within_nms_radius_fast(pose_coords, squared_nms_radius, point):
if not pose_coords.shape[0]:
return False
return np.any(np.sum((pose_coords - point) ** 2, axis=1) <= squared_nms_radius)
def get_instance_score_fast(
exist_pose_coords,
squared_nms_radius,
keypoint_scores, keypoint_coords):
if exist_pose_coords.shape[0]:
s = np.sum((exist_pose_coords - keypoint_coords) ** 2, axis=2) > squared_nms_radius
not_overlapped_scores = np.sum(keypoint_scores[np.all(s, axis=0)])
else:
not_overlapped_scores = np.sum(keypoint_scores)
return not_overlapped_scores / len(keypoint_scores)
def build_part_with_score_torch(score_threshold, local_max_radius, scores):
lmd = 2 * local_max_radius + 1
max_vals = F.max_pool2d(scores, lmd, stride=1, padding=1)
max_loc = (scores == max_vals) & (scores >= score_threshold)
max_loc_idx = max_loc.nonzero()
scores_vec = scores[max_loc]
sort_idx = torch.argsort(scores_vec, descending=True)
return scores_vec[sort_idx], max_loc_idx[sort_idx]
# FIXME leaving here as reference for now
# def build_part_with_score_fast(score_threshold, local_max_radius, scores):
# parts = []
# num_keypoints = scores.shape[0]
# lmd = 2 * local_max_radius + 1
#
# # NOTE it seems faster to iterate over the keypoints and perform maximum_filter
# # on each subarray vs doing the op on the full score array with size=(lmd, lmd, 1)
# for keypoint_id in range(num_keypoints):
# kp_scores = scores[keypoint_id, :, :].copy()
# kp_scores[kp_scores < score_threshold] = 0.
# max_vals = ndi.maximum_filter(kp_scores, size=lmd, mode='constant')
# max_loc = np.logical_and(kp_scores == max_vals, kp_scores > 0)
# max_loc_idx = max_loc.nonzero()
# for y, x in zip(*max_loc_idx):
# parts.append((
# scores[keypoint_id, y, x],
# keypoint_id,
# np.array((y, x))
# ))
#
# return parts
def decode_multiple_poses(
scores, offsets, displacements_fwd, displacements_bwd, output_stride,
max_pose_detections=10, score_threshold=0.5, nms_radius=20, min_pose_score=0.5):
# perform part scoring step on GPU as it's expensive
# TODO determine how much more of this would be worth performing on the GPU
part_scores, part_idx = build_part_with_score_torch(score_threshold, LOCAL_MAXIMUM_RADIUS, scores)
part_scores = part_scores.cpu().numpy()
part_idx = part_idx.cpu().numpy()
scores = scores.cpu().numpy()
height = scores.shape[1]
width = scores.shape[2]
# change dimensions from (x, h, w) to (x//2, h, w, 2) to allow return of complete coord array
offsets = offsets.cpu().numpy().reshape(2, -1, height, width).transpose((1, 2, 3, 0))
displacements_fwd = displacements_fwd.cpu().numpy().reshape(2, -1, height, width).transpose((1, 2, 3, 0))
displacements_bwd = displacements_bwd.cpu().numpy().reshape(2, -1, height, width).transpose((1, 2, 3, 0))
squared_nms_radius = nms_radius ** 2
pose_count = 0
pose_scores = np.zeros(max_pose_detections)
pose_keypoint_scores = np.zeros((max_pose_detections, NUM_KEYPOINTS))
pose_keypoint_coords = np.zeros((max_pose_detections, NUM_KEYPOINTS, 2))
for root_score, (root_id, root_coord_y, root_coord_x) in zip(part_scores, part_idx):
root_coord = np.array([root_coord_y, root_coord_x])
root_image_coords = root_coord * output_stride + offsets[root_id, root_coord_y, root_coord_x]
if within_nms_radius_fast(
pose_keypoint_coords[:pose_count, root_id, :], squared_nms_radius, root_image_coords):
continue
keypoint_scores, keypoint_coords = decode_pose(
root_score, root_id, root_image_coords,
scores, offsets, output_stride,
displacements_fwd, displacements_bwd)
pose_score = get_instance_score_fast(
pose_keypoint_coords[:pose_count, :, :], squared_nms_radius, keypoint_scores, keypoint_coords)
# NOTE this isn't in the original implementation, but it appears that by initially ordering by
# part scores, and having a max # of detections, we can end up populating the returned poses with
# lower scored poses than if we discard 'bad' ones and continue (higher pose scores can still come later).
# Set min_pose_score to 0. to revert to original behaviour
if min_pose_score == 0. or pose_score >= min_pose_score:
pose_scores[pose_count] = pose_score
pose_keypoint_scores[pose_count, :] = keypoint_scores
pose_keypoint_coords[pose_count, :, :] = keypoint_coords
pose_count += 1
if pose_count >= max_pose_detections:
break
return pose_scores, pose_keypoint_scores, pose_keypoint_coords