Spaces:
Running
on
Zero
Running
on
Zero
File size: 4,825 Bytes
aaf39d1 |
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 |
# Copyright 2023 Bingxin Ke, ETH Zurich. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
# --------------------------------------------------------------------------
# If you find this code useful, we kindly ask you to cite our paper in your work.
# Please find bibtex at: https://github.com/prs-eth/Marigold#-citation
# More information about the method can be found at https://marigoldmonodepth.github.io
# --------------------------------------------------------------------------
import numpy as np
import torch
from scipy.optimize import minimize
def inter_distances(tensors: torch.Tensor):
"""
To calculate the distance between each two depth maps.
"""
distances = []
for i, j in torch.combinations(torch.arange(tensors.shape[0])):
arr1 = tensors[i : i + 1]
arr2 = tensors[j : j + 1]
distances.append(arr1 - arr2)
dist = torch.concatenate(distances, dim=0)
return dist
def ensemble_depths(
input_images: torch.Tensor,
regularizer_strength: float = 0.02,
max_iter: int = 2,
tol: float = 1e-3,
reduction: str = "median",
max_res: int = None,
):
"""
To ensemble multiple affine-invariant depth images (up to scale and shift),
by aligning estimating the scale and shift
"""
device = input_images.device
dtype = input_images.dtype
np_dtype = np.float32
original_input = input_images.clone()
n_img = input_images.shape[0]
ori_shape = input_images.shape
if max_res is not None:
scale_factor = torch.min(max_res / torch.tensor(ori_shape[-2:]))
if scale_factor < 1:
downscaler = torch.nn.Upsample(scale_factor=scale_factor, mode="nearest")
input_images = downscaler(input_images)
# init guess
_min = np.min(input_images.reshape((n_img, -1)).cpu().numpy(), axis=1)
_max = np.max(input_images.reshape((n_img, -1)).cpu().numpy(), axis=1)
s_init = 1.0 / (_max - _min).reshape((-1, 1, 1))
t_init = (-1 * s_init.flatten() * _min.flatten()).reshape((-1, 1, 1))
x = np.concatenate([s_init, t_init]).reshape(-1).astype(np_dtype)
input_images = input_images.to(device)
# objective function
def closure(x):
len_x = len(x)
s = x[: int(len_x / 2)]
t = x[int(len_x / 2) :]
s = torch.from_numpy(s).to(dtype=dtype).to(device)
t = torch.from_numpy(t).to(dtype=dtype).to(device)
transformed_arrays = input_images * s.view((-1, 1, 1)) + t.view((-1, 1, 1))
dists = inter_distances(transformed_arrays)
sqrt_dist = torch.sqrt(torch.mean(dists**2))
if "mean" == reduction:
pred = torch.mean(transformed_arrays, dim=0)
elif "median" == reduction:
pred = torch.median(transformed_arrays, dim=0).values
else:
raise ValueError
near_err = torch.sqrt((0 - torch.min(pred)) ** 2)
far_err = torch.sqrt((1 - torch.max(pred)) ** 2)
err = sqrt_dist + (near_err + far_err) * regularizer_strength
err = err.detach().cpu().numpy().astype(np_dtype)
return err
res = minimize(
closure, x, method="BFGS", tol=tol, options={"maxiter": max_iter, "disp": False}
)
x = res.x
len_x = len(x)
s = x[: int(len_x / 2)]
t = x[int(len_x / 2) :]
# Prediction
s = torch.from_numpy(s).to(dtype=dtype).to(device)
t = torch.from_numpy(t).to(dtype=dtype).to(device)
transformed_arrays = original_input * s.view(-1, 1, 1) + t.view(-1, 1, 1)
if "mean" == reduction:
aligned_images = torch.mean(transformed_arrays, dim=0)
std = torch.std(transformed_arrays, dim=0)
uncertainty = std
elif "median" == reduction:
aligned_images = torch.median(transformed_arrays, dim=0).values
# MAD (median absolute deviation) as uncertainty indicator
abs_dev = torch.abs(transformed_arrays - aligned_images)
mad = torch.median(abs_dev, dim=0).values
uncertainty = mad
else:
raise ValueError(f"Unknown reduction method: {reduction}")
# Scale and shift to [0, 1]
_min = torch.min(aligned_images)
_max = torch.max(aligned_images)
aligned_images = (aligned_images - _min) / (_max - _min)
uncertainty /= _max - _min
return aligned_images, uncertainty
|