import numpy as np
from shapely.geometry import LineString, Point, Polygon
import mmocr.utils as utils
[docs]def sort_vertex(points_x, points_y):
"""Sort box vertices in clockwise order from left-top first.
Args:
points_x (list[float]): x of four vertices.
points_y (list[float]): y of four vertices.
Returns:
sorted_points_x (list[float]): x of sorted four vertices.
sorted_points_y (list[float]): y of sorted four vertices.
"""
assert utils.is_type_list(points_x, float) or utils.is_type_list(
points_x, int)
assert utils.is_type_list(points_y, float) or utils.is_type_list(
points_y, int)
assert len(points_x) == 4
assert len(points_y) == 4
x = np.array(points_x)
y = np.array(points_y)
center_x = np.sum(x) * 0.25
center_y = np.sum(y) * 0.25
x_arr = np.array(x - center_x)
y_arr = np.array(y - center_y)
angle = np.arctan2(y_arr, x_arr) * 180.0 / np.pi
sort_idx = np.argsort(angle)
sorted_points_x, sorted_points_y = [], []
for i in range(4):
sorted_points_x.append(points_x[sort_idx[i]])
sorted_points_y.append(points_y[sort_idx[i]])
return convert_canonical(sorted_points_x, sorted_points_y)
def convert_canonical(points_x, points_y):
"""Make left-top be first.
Args:
points_x (list[float]): x of four vertices.
points_y (list[float]): y of four vertices.
Returns:
sorted_points_x (list[float]): x of sorted four vertices.
sorted_points_y (list[float]): y of sorted four vertices.
"""
assert utils.is_type_list(points_x, float) or utils.is_type_list(
points_x, int)
assert utils.is_type_list(points_y, float) or utils.is_type_list(
points_y, int)
assert len(points_x) == 4
assert len(points_y) == 4
points = [Point(points_x[i], points_y[i]) for i in range(4)]
polygon = Polygon([(p.x, p.y) for p in points])
min_x, min_y, _, _ = polygon.bounds
points_to_lefttop = [
LineString([points[i], Point(min_x, min_y)]) for i in range(4)
]
distances = np.array([line.length for line in points_to_lefttop])
sort_dist_idx = np.argsort(distances)
lefttop_idx = sort_dist_idx[0]
if lefttop_idx == 0:
point_orders = [0, 1, 2, 3]
elif lefttop_idx == 1:
point_orders = [1, 2, 3, 0]
elif lefttop_idx == 2:
point_orders = [2, 3, 0, 1]
else:
point_orders = [3, 0, 1, 2]
sorted_points_x = [points_x[i] for i in point_orders]
sorted_points_y = [points_y[j] for j in point_orders]
return sorted_points_x, sorted_points_y