Question about how to generate systhesis dataset
Opened this issue · 2 comments
ronghui19 commented
import numpy as np
import matplotlib.pyplot as plt
import cv2
def create_grid(width=100, height=100):
mr = width
mc = height
xx = np.arange(mr-1, -1, -1)
yy = np.arange(0, mc, 1)
[Y, X] = np.meshgrid(xx, yy)
ms = np.transpose(np.asarray([X.flatten('F'), Y.flatten('F')]), (1,0))
perturbed_mesh = ms
nv = np.random.randint(20) - 1
for k in range(nv):
#Choosing one vertex randomly
vidx = np.random.randint(np.shape(ms)[1])
vtex = ms[vidx, :]
#Vector between all vertices and the selected one
xv = perturbed_mesh - vtex
#Random movement
mv = (np.random.rand(1,2) - 0.5)*20
hxv = np.zeros((np.shape(xv)[0], np.shape(xv)[1] +1))
hxv[:, :-1] = xv
hmv = np.tile(np.append(mv, 0), (np.shape(xv)[0],1))
d = np.cross(hxv, hmv)
d = np.absolute(d[:, 2])
d = d / (np.linalg.norm(mv, ord=2))
wt = d
curve_type = np.random.rand(1)
if curve_type > 0.3:
alpha = np.random.rand(1) * 20 + 20
wt = alpha / (wt + alpha)
else:
alpha = np.random.rand(1) + 1
wt = 1 - (wt/ 100)**alpha
msmv = mv * np.expand_dims(wt, axis=1)
perturbed_mesh = perturbed_mesh + msmv
perturbed_mesh[:, 0] = np.where(perturbed_mesh[:, 0] > height, height, perturbed_mesh[:, 0])
perturbed_mesh[:, 1] = np.where(perturbed_mesh[:, 1] > width, width, perturbed_mesh[:, 1])
# plt.scatter(perturbed_mesh[:, 0], perturbed_mesh[:, 1], c=np.arange(0, mr*mc))
# plt.show()
return perturbed_mesh[:, 0], perturbed_mesh[:, 1]
src_img = cv2.imread('source.jpg')
height, width, _ = src_img.shape
dh = height // 20
dw = width // 20
img = cv2.copyMakeBorder(src_img, dh, dh, dw, dw, borderType=cv2.BORDER_CONSTANT, value=(0,0,0))
nh, nw, _ = img.shape
xs, ys = create_grid(nh, nw)
xs = xs.reshape(nh, nw).astype(np.float32)
ys = ys.reshape(nh, nw).astype(np.float32)
dst = cv2.remap(src_img, xs, ys, cv2.INTER_CUBIC)
cv2.imwrite('result.jpg', dst)
ronghui19 commented
code above is a way to create fake data. But sometime image's over distorted and it's flipped. Can anyone spot the mistake i made? Here is the question i asked here on stackoverflow.
keepfoolisher commented
above code only provide warpped images, but how can you get the restore image matrix @ronghui19