def rotate_vertices(vertices, theta, anchor=None):
'''rotate vertices around anchor
Input:
vertices: vertices of text region <numpy.ndarray, (8,)>
theta : angle in radian measure
anchor : fixed position during rotation
Output:
rotated vertices <numpy.ndarray, (8,)>
'''
v = vertices.reshape((4, 2)).T
if anchor is None:
anchor = v[:, :1]
rotate_mat = get_rotate_mat(theta)
res = np.dot(rotate_mat, v - anchor)
return (res + anchor).T.reshape(-1)
def restore_polys(valid_pos, valid_geo, score_shape, scale=4):
"""
restore polys from feature maps in given positions.
Input:
valid_pos : potential text positions <numpy.ndarray, (n,2)>, each one is in form (x ,y)
valid_geo : geometry in valid_pos <numpy.ndarray, (5,n)>, value of d1,d2,d3,d4,angle for each point
score_shape: shape of score map
scale : image / feature map
Output:
restored polys <numpy.ndarray, (n,8)>, index
"""
polys = []
index = []
# project to image size
valid_pos *= scale
d = valid_geo[:4, :] # 4 x N
angle = valid_geo[4, :] # N,
for i in range(valid_pos.shape[0]):
x = valid_pos[i, 0]
y = valid_pos[i, 1]
y_min = y - d[0, i]
y_max = y + d[1, i]
x_min = x - d[2, i]
x_max = x + d[3, i]
# 角度设置为负值，代表逆时针旋转
rotate_mat = get_rotate_mat(-angle[i])
# 以(x, y)为中心点逆时针旋转
temp_x = np.array([[x_min, x_max, x_max, x_min]]) - x
temp_y = np.array([[y_min, y_min, y_max, y_max]]) - y
coordidates = np.concatenate((temp_x, temp_y), axis=0)
# shape: (2, 4)
res = np.dot(rotate_mat, coordidates)
res[0, :] += x
res[1, :] += y
if is_valid_poly(res, score_shape, scale):
index.append(i)
polys.append([res[0, 0], res[1, 0], res[0, 1], res[1, 1], res[0, 2], res[1, 2], res[0, 3], res[1, 3]])
return np.array(polys), index
def restore_polys(valid_pos, valid_geo, score_shape, scale=4):
'''restore polys from feature maps in given positions
Input:
valid_pos : potential text positions <numpy.ndarray, (n,2)>
valid_geo : geometry in valid_pos <numpy.ndarray, (5,n)>
score_shape: shape of score map
scale : image / feature map
Output:
restored polys <numpy.ndarray, (n,8)>, index
'''
polys = []
index = []
valid_pos *= scale
d = valid_geo[:4, :] # 4 x N
angle = valid_geo[4, :] # N,
for i in range(valid_pos.shape[0]):
x = valid_pos[i, 0]
y = valid_pos[i, 1]
# d1, d2, d3, d4
y_min = y - d[0, i]
x_max = x + d[1, i]
y_max = y + d[2, i]
x_min = x - d[3, i]
rotate_mat = get_rotate_mat(-angle[i])
temp_x = np.array([[x_min, x_max, x_max, x_min]]) - x
temp_y = np.array([[y_min, y_min, y_max, y_max]]) - y
coordidates = np.concatenate((temp_x, temp_y), axis=0)
res = np.dot(rotate_mat, coordidates)
res[0, :] += x
res[1, :] += y
if is_valid_poly(res, score_shape, scale):
index.append(i)
polys.append([
res[0, 0], res[1, 0], res[0, 1], res[1, 1], res[0, 2],
res[1, 2], res[0, 3], res[1, 3]
])
return np.array(polys), index
