File size: 4,565 Bytes
4f6b78d |
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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 |
import numpy as np
import cv2
from functools import wraps
from matplotlib import pyplot as plt
import torch
MAX_VALUES_BY_DTYPE = {
np.dtype('uint8'): 255,
np.dtype('uint16'): 65535,
np.dtype('uint32'): 4294967295,
np.dtype('float32'): 1.0,
}
UNKNOWN_FLOW_THRESH = 1e7
SMALLFLOW = 0.0
LARGEFLOW = 1e8
def flow2rgb(flow_map, max_value):
if isinstance(flow_map,np.ndarray):
if flow_map.shape[2] == 2:
flow_map = flow_map.transpose(2,0, 1)
flow_map_np = flow_map
else:
if flow_map.shape[2] == 2:
# shape is HxWx2
flow_map = flow_map.permute(2, 0, 1)
flow_map_np = flow_map.detach().cpu().numpy()
_, h, w = flow_map_np.shape
flow_map_np[:,(flow_map_np[0] == 0) & (flow_map_np[1] == 0)] = float('nan')
rgb_map = np.ones((3,h,w)).astype(np.float32)
if max_value is not None:
normalized_flow_map = flow_map_np / max_value
else:
normalized_flow_map = flow_map_np / (np.abs(flow_map_np).max())
rgb_map[0] += normalized_flow_map[0]
rgb_map[1] -= 0.5*(normalized_flow_map[0] + normalized_flow_map[1])
rgb_map[2] += normalized_flow_map[1]
return rgb_map.clip(0,1)
def flow_to_image(flow, maxrad=None):
"""
Convert flow into middlebury color code image
:param flow: optical flow map
:return: optical flow image in middlebury color
"""
h,w, _ = flow.shape
u = flow[:, :, 0]
v = flow[:, :, 1]
maxu = -999.
maxv = -999.
minu = 999.
minv = 999.
idxUnknow = (abs(u) > UNKNOWN_FLOW_THRESH) | (abs(v) > UNKNOWN_FLOW_THRESH)
u[idxUnknow] = 0
v[idxUnknow] = 0
if maxrad is None:
rad = np.sqrt(u ** 2 + v ** 2)
maxrad = max(-1, np.max(rad))
#print("max flow: %.4f\nflow range:\nu = %.3f .. %.3f\nv = %.3f .. %.3f" % (maxrad, minu,maxu, minv, maxv))
u = u/(maxrad + np.finfo(float).eps)
v = v/(maxrad + np.finfo(float).eps)
img = compute_color(u, v)
idx = np.repeat(idxUnknow[:, :, np.newaxis], 3, axis=2)
img[idx] = 0
valid = np.ones((h,w), np.uint8)
valid[np.logical_and(u == 0 , v == 0)] = 0
return np.uint8(img)*np.expand_dims(valid, axis=2)
def show_flow(flow):
"""
visualize optical flow map using matplotlib
:param filename: optical flow file
:return: None
"""
img = flow_to_image(flow)
plt.imshow(img)
plt.show()
return img
def compute_color(u, v):
"""
compute optical flow color map
:param u: optical flow horizontal map
:param v: optical flow vertical map
:return: optical flow in color code
"""
[h, w] = u.shape
img = np.zeros([h, w, 3])
nanIdx = np.isnan(u) | np.isnan(v)
u[nanIdx] = 0
v[nanIdx] = 0
colorwheel = make_color_wheel()
ncols = np.size(colorwheel, 0)
rad = np.sqrt(u**2+v**2)
a = np.arctan2(-v, -u) / np.pi
fk = (a+1) / 2 * (ncols - 1) + 1
k0 = np.floor(fk).astype(int)
k1 = k0 + 1
k1[k1 == ncols+1] = 1
f = fk - k0
for i in range(0, np.size(colorwheel,1)):
tmp = colorwheel[:, i]
col0 = tmp[k0-1] / 255
col1 = tmp[k1-1] / 255
col = (1-f) * col0 + f * col1
idx = rad <= 1
col[idx] = 1-rad[idx]*(1-col[idx])
notidx = np.logical_not(idx)
col[notidx] *= 0.75
img[:, :, i] = np.uint8(np.floor(255 * col*(1-nanIdx)))
return img
def make_color_wheel():
"""
Generate color wheel according Middlebury color code
:return: Color wheel
"""
RY = 15
YG = 6
GC = 4
CB = 11
BM = 13
MR = 6
ncols = RY + YG + GC + CB + BM + MR
colorwheel = np.zeros([ncols, 3])
col = 0
# RY
colorwheel[0:RY, 0] = 255
colorwheel[0:RY, 1] = np.transpose(np.floor(255*np.arange(0, RY) / RY))
col += RY
# YG
colorwheel[col:col+YG, 0] = 255 - np.transpose(np.floor(255*np.arange(0, YG) / YG))
colorwheel[col:col+YG, 1] = 255
col += YG
# GC
colorwheel[col:col+GC, 1] = 255
colorwheel[col:col+GC, 2] = np.transpose(np.floor(255*np.arange(0, GC) / GC))
col += GC
# CB
colorwheel[col:col+CB, 1] = 255 - np.transpose(np.floor(255*np.arange(0, CB) / CB))
colorwheel[col:col+CB, 2] = 255
col += CB
# BM
colorwheel[col:col+BM, 2] = 255
colorwheel[col:col+BM, 0] = np.transpose(np.floor(255*np.arange(0, BM) / BM))
col += + BM
# MR
colorwheel[col:col+MR, 2] = 255 - np.transpose(np.floor(255 * np.arange(0, MR) / MR))
colorwheel[col:col+MR, 0] = 255
return colorwheel
|