2025-05-13 09:03:38 +08:00

117 lines
4.9 KiB
Python

import numpy as np
import open3d as o3d
import torch
class PtsUtil:
@staticmethod
def voxel_downsample_point_cloud(point_cloud, voxel_size=0.005, require_idx=False):
voxel_indices = np.floor(point_cloud / voxel_size).astype(np.int32)
if require_idx:
_, inverse, counts = np.unique(voxel_indices, axis=0, return_inverse=True, return_counts=True)
idx_sort = np.argsort(inverse)
idx_unique = idx_sort[np.cumsum(counts)-counts]
downsampled_points = point_cloud[idx_unique]
return downsampled_points, idx_unique
else:
unique_voxels = np.unique(voxel_indices, axis=0, return_inverse=True)
return unique_voxels[0]*voxel_size
@staticmethod
def voxel_downsample_point_cloud_random(point_cloud, voxel_size=0.005, require_idx=False):
voxel_indices = np.floor(point_cloud / voxel_size).astype(np.int32)
unique_voxels, inverse, counts = np.unique(voxel_indices, axis=0, return_inverse=True, return_counts=True)
idx_sort = np.argsort(inverse)
idx_unique = idx_sort[np.cumsum(counts)-counts]
downsampled_points = point_cloud[idx_unique]
if require_idx:
return downsampled_points, inverse
return downsampled_points
@staticmethod
def random_downsample_point_cloud(point_cloud, num_points, require_idx=False):
if point_cloud.shape[0] == 0:
if require_idx:
return point_cloud, np.array([])
return point_cloud
idx = np.random.choice(len(point_cloud), num_points, replace=True)
if require_idx:
return point_cloud[idx], idx
return point_cloud[idx]
@staticmethod
def fps_downsample_point_cloud(point_cloud, num_points, require_idx=False):
N = point_cloud.shape[0]
mask = np.zeros(N, dtype=bool)
sampled_indices = np.zeros(num_points, dtype=int)
sampled_indices[0] = np.random.randint(0, N)
distances = np.linalg.norm(point_cloud - point_cloud[sampled_indices[0]], axis=1)
for i in range(1, num_points):
farthest_index = np.argmax(distances)
sampled_indices[i] = farthest_index
mask[farthest_index] = True
new_distances = np.linalg.norm(point_cloud - point_cloud[farthest_index], axis=1)
distances = np.minimum(distances, new_distances)
sampled_points = point_cloud[sampled_indices]
if require_idx:
return sampled_points, sampled_indices
return sampled_points
@staticmethod
def random_downsample_point_cloud_tensor(point_cloud, num_points):
idx = torch.randint(0, len(point_cloud), (num_points,))
return point_cloud[idx]
@staticmethod
def voxelize_points(points, voxel_size):
voxel_indices = np.floor(points / voxel_size).astype(np.int32)
unique_voxels = np.unique(voxel_indices, axis=0, return_inverse=True)
return unique_voxels
@staticmethod
def transform_point_cloud(points, pose_mat):
points_h = np.concatenate([points, np.ones((points.shape[0], 1))], axis=1)
points_h = np.dot(pose_mat, points_h.T).T
return points_h[:, :3]
@staticmethod
def get_overlapping_points(point_cloud_L, point_cloud_R, voxel_size=0.005, require_idx=False):
voxels_L, indices_L = PtsUtil.voxelize_points(point_cloud_L, voxel_size)
voxels_R, _ = PtsUtil.voxelize_points(point_cloud_R, voxel_size)
voxel_indices_L = voxels_L.view([("", voxels_L.dtype)] * 3)
voxel_indices_R = voxels_R.view([("", voxels_R.dtype)] * 3)
overlapping_voxels = np.intersect1d(voxel_indices_L, voxel_indices_R)
mask_L = np.isin(
indices_L, np.where(np.isin(voxel_indices_L, overlapping_voxels))[0]
)
overlapping_points = point_cloud_L[mask_L]
if require_idx:
return overlapping_points, mask_L
return overlapping_points
@staticmethod
def filter_points(points, normals, cam_pose, theta_limit=45, z_range=(0.2, 0.45)):
""" filter with normal """
normals_normalized = normals / np.linalg.norm(normals, axis=1, keepdims=True)
cos_theta = np.dot(normals_normalized, np.array([0, 0, 1]))
theta = np.arccos(cos_theta) * 180 / np.pi
idx = theta < theta_limit
filtered_sampled_points = points[idx]
filtered_normals = normals[idx]
""" filter with z range """
points_cam = PtsUtil.transform_point_cloud(filtered_sampled_points, np.linalg.inv(cam_pose))
idx = (points_cam[:, 2] > z_range[0]) & (points_cam[:, 2] < z_range[1])
z_filtered_points = filtered_sampled_points[idx]
z_filtered_normals = filtered_normals[idx]
return z_filtered_points[:, :3], z_filtered_normals
@staticmethod
def point_to_hash(point, voxel_size):
return tuple(np.floor(point / voxel_size).astype(int))