# -*- coding:utf-8 -*-
# author : gfjiangly
# time : 2019/6/10 11:13
# e-mail : jgf0719@foxmail.com
# software : PyCharm
import numpy as np
import cv2.cv2 as cv
from shapely.geometry import Polygon
[文档]def x1y1wh_to_x1y1x2y2(xywh):
"""Convert [x1 y1 w h] box format to [x1 y1 x2 y2] format.
supported type: list, type and np.ndarray
"""
if isinstance(xywh, (list, tuple)):
# Single box given as a list of coordinates
assert len(xywh) == 4
x1, y1 = xywh[0], xywh[1]
x2 = x1 + np.maximum(0., xywh[2] - 1.)
y2 = y1 + np.maximum(0., xywh[3] - 1.)
return [x1, y1, x2, y2]
elif isinstance(xywh, np.ndarray):
# Multiple boxes given as a 2D ndarray
return np.hstack(
(xywh[:, 0:2], xywh[:, 0:2] + np.maximum(0, xywh[:, 2:4] - 1))
)
else:
raise TypeError('Argument xywh must be a list, tuple, or numpy array.')
[文档]def x1y1x2y2_to_x1y1wh(xyxy):
"""Convert [x1 y1 x2 y2] box format to [x1 y1 w h] format."""
if isinstance(xyxy, (list, tuple)):
# Single box given as a list of coordinates
assert len(xyxy) == 4
x1, y1 = xyxy[0], xyxy[1]
w = xyxy[2] - x1 + 1
h = xyxy[3] - y1 + 1
return [x1, y1, w, h]
elif isinstance(xyxy, np.ndarray):
# Multiple boxes given as a 2D ndarray
return np.hstack((xyxy[:, 0:2], xyxy[:, 2:4] - xyxy[:, 0:2] + 1))
else:
raise TypeError('Argument xyxy must be a list, tuple, or numpy array.')
[文档]def x1y1wh_to_x1y1x2y2x3y3x4y4(xywh):
"""Convert [x1 y1 w h] box format to [x1 y1 x2 y2 x3 y3 x4 y4] format.
supported type: list, type and np.ndarray
"""
if isinstance(xywh, (list, tuple)):
# Single box given as a list of coordinates
assert len(xywh) == 4
x1, y1 = xywh[0], xywh[1]
x4 = x1 + np.maximum(0., xywh[2] - 1.)
y4 = y1 + np.maximum(0., xywh[3] - 1.)
return [x1, y1, x4, y1, x4, y4, x1, y4]
elif isinstance(xywh, np.ndarray):
# Multiple boxes given as a 2D ndarray
x1y1 = xywh[:, 0:2]
x4y4 = xywh[:, 0:2] + np.maximum(0, xywh[:, 2:4] - 1)
return np.hstack(
(x1y1, np.hstack((x4y4[..., 0], x1y1[..., 1])),
x4y4, np.hstack((x1y1[..., 0], x4y4[..., 1])))
)
else:
raise TypeError('Argument xywh must be a list, tuple, or numpy array.')
[文档]def polygon_to_x1y1wh(polygon):
"""求polygon的外接正矩形
Args:
polygon (list or np.array): 多边形点集
Returns:
tuple: x1y1wh形式矩形
"""
if not isinstance(polygon, np.ndarray):
polygon = np.array(polygon)
polygon = polygon.reshape(-1, 2)
x1y1wh = cv.boundingRect(polygon)
return x1y1wh
[文档]def xywh_to_x1y1x2y2(xywh):
"""Convert [x y w h] box format to [x1 y1 x2 y2] format."""
if isinstance(xywh, (list, tuple)):
# Single box given as a list of coordinates
assert len(xywh) == 4
x1, y1 = xywh[0] - xywh[2] / 2, xywh[1] - xywh[3] / 2
x2, y2 = xywh[0] + xywh[2] / 2, xywh[1] + xywh[3] / 2
return x1, y1, x2, y2
elif isinstance(xywh, np.ndarray):
# Multiple boxes given as a 2D ndarray
return np.hstack(
(xywh[:, 0:2] - xywh[:, 2:4] / 2, xywh[:, 0:2] + xywh[:, 2:4] / 2)
)
else:
raise TypeError('Argument xywh must be a list, tuple, or numpy array.')
[文档]def x1y1x2y2_to_xywh(x1y1x2y2):
"""Convert [x1 y1 x2 y2] box format to [x y w h] format."""
if isinstance(x1y1x2y2, (list, tuple)):
# Single box given as a list of coordinates
assert len(x1y1x2y2) == 4
ct_x, ct_y = (x1y1x2y2[3] + x1y1x2y2[1]) / 2, (x1y1x2y2[2] + x1y1x2y2[0]) / 2
w, h = x1y1x2y2[3] - x1y1x2y2[1] + 1, x1y1x2y2[2] - x1y1x2y2[0] + 1
return ct_x, ct_y, w, h
elif isinstance(x1y1x2y2, np.ndarray):
# Multiple boxes given as a 2D ndarray
return np.hstack(
((x1y1x2y2[:, 0:2] + x1y1x2y2[:, 2:4]) / 2, x1y1x2y2[:, 2:4] - x1y1x2y2[:, 0:2] + 1)
)
else:
raise TypeError('Argument x1y1x2y2 must be a list, tuple, or numpy array.')
[文档]def x1y1wh_to_xywh(x1y1wh):
"""Convert [x1 y1 w h] box format to [x y w h] format.
supported type: list, type and np.ndarray
"""
if isinstance(x1y1wh, (list, tuple)):
# Single box given as a list of coordinates
assert len(x1y1wh) == 4
w = x1y1wh[2]
h = x1y1wh[3]
x, y = x1y1wh[0] + w/2, x1y1wh[1] + h/2
return x, y, w, h
elif isinstance(x1y1wh, np.ndarray):
# Multiple boxes given as a 2D ndarray
return np.hstack(
(x1y1wh[:, 0:2]+x1y1wh[:, 2:4]/2, x1y1wh[:, 2:4])
)
else:
raise TypeError('Argument x1y1wh must be a list, tuple, or numpy array.')
# 已测试
[文档]def rotate_rect(rect, center, angle):
"""一个数学问题：2x2矩阵（坐标）与旋转矩阵相乘.
在笛卡尔坐标系中，angle>0, 逆时针旋转; angle<0, 顺时针旋转
Args:
rect: x1y1x2y2形式矩形
center: 旋转中心点
angle: 旋转角度，范围在(-180, 180)
Returns:
x1y1x2y2x3y3x4y4 format box
"""
assert 180 > angle > -180
# 顺时针排列坐标
x1, y1, x3, y3 = rect
x2, y2, x4, y4 = x3, y1, x1, y3
x, y = center
# anti-clockwise to clockwise arc
cosA = np.cos(np.pi / 180. * angle)
sinA = np.sin(np.pi / 180. * angle)
x1n = (x1 - x) * cosA - (y1 - y) * sinA + x
y1n = (x1 - x) * sinA + (y1 - y) * cosA + y
x2n = (x2 - x) * cosA - (y2 - y) * sinA + x
y2n = (x2 - x) * sinA + (y2 - y) * cosA + y
x3n = (x3 - x) * cosA - (y3 - y) * sinA + x
y3n = (x3 - x) * sinA + (y3 - y) * cosA + y
x4n = (x4 - x) * cosA - (y4 - y) * sinA + x
y4n = (x4 - x) * sinA + (y4 - y) * cosA + y
return [x1n, y1n, x2n, y2n, x3n, y3n, x4n, y4n] # 顺时针方向
[文档]def rotate_rects(rects, centers, angle):
"""一个数学问题：坐标矩阵与旋转矩阵相乘.
在笛卡尔坐标系中，angle>0, 逆时针旋转; angle<0, 顺时针旋转
return: x1y1x2y2x3y3x4y4 format box
Args:
rects: x1y1x2y2形式list或array
centers: 旋转中心
angle: 旋转角度
"""
if not isinstance(rects, np.ndarray):
rects = np.array([rects])
if not isinstance(centers, np.ndarray):
centers = np.array([centers])
assert len(centers) == len(rects) > 0
# assert 180 > angle > -180
# 顺时针排列坐标
rects = np.hstack((rects[:, :2],
rects[:, 2:3], rects[:, 1:2],
rects[:, 2:4],
rects[:, 0:1], rects[:, 3:4]))
coors = rects.reshape(-1, 2)
cosA = np.tile(np.cos(np.pi / 180. * angle), (4, 1)).reshape(-1, 1)
sinA = np.tile(np.sin(np.pi / 180. * angle), (4, 1)).reshape(-1, 1)
x, y = coors[:, 0:1], coors[:, 1:2]
x0, y0 = np.tile(centers[:, 0:1], (4, 1)), np.tile(centers[:, 1:2], (4, 1))
xn = (x - x0) * cosA - (y - y0) * sinA + x0
yn = (x - x0) * sinA + (y - y0) * cosA + y0
return np.hstack((xn, yn)).reshape(-1, 8) # 顺时针方向
[文档]def xywha_to_x1y1x2y2x3y3x4y4(xywha):
"""用旋转的思路做变换是最通用和最简单的
警告：目前多维一起操作还有些问题！
Args:
xywha: (5,)一维list或(K, 5)多维array
"""
if isinstance(xywha, (list, tuple)):
assert len(xywha) == 5
return rotate_rect(xywha[:4], xywha[:2], xywha[4:5])
elif isinstance(xywha, np.ndarray):
return rotate_rects(xywha[:, :4], xywha[:, :2], xywha[:, 4:5])
else:
raise TypeError('Argument xywha must be a list, tuple, or numpy array.')
[文档]def tran_xywha_to_rbox(xywha):
"""包装opencv的cv.boxPoints函数
Args:
xywha: ((xy),(wh),angle)形式tuple或list, xy为中心点
"""
if len(xywha) != 3:
xywha = (xywha[:2], xywha[2:4], xywha[4])
return cv.boxPoints(xywha) # 返回4*2数组
[文档]def get_min_area_rect(cnt):
"""包装cv.minAreaRect
Args:
cnt: (np.ndarray): [x1, y1, x2, y2, x3, y3, x4, y4, ...]
Returns:
xywha：((x,y), (w,h), a), (x,y) is Oriented Bounding Box（OBB）'s center point,
a is orientation, which range is [-90, 0)
"""
assert isinstance(cnt, np.ndarray)
cnt = cnt.reshape(-1, 2)
# the clockwise output convex hull in the Cartesian coordinate system
cnt_hull = cv.convexHull(cnt.astype(np.float32), clockwise=False)
xywha = cv.minAreaRect(cnt_hull)
return xywha
[文档]def trans_polygon_to_rbox(polygon):
"""求polygon的最小外接旋转矩形
Args:
polygon: 一维数组，或(K, 2)数组
"""
if not isinstance(polygon, np.ndarray):
polygon = np.array(polygon)
polygon = polygon.reshape(-1, 2).astype(np.float32)
segm_hull = cv.convexHull(polygon, clockwise=False)
xywha = cv.minAreaRect(segm_hull)
rbox = cv.boxPoints(xywha).reshape(-1).tolist()
return rbox
[文档]def cut_polygon(polygon, box):
"""求polygon与矩形框的交点，返回交点与外接矩形
Args:
polygon (list or np.array): 多边形，支持一维list或(K,2)list/array
不必保持点的顺序
box (list or np.array): 必须是4个点形式list或array
Returns:
tuple: 第一个元素是交点, (K,2)数组；第二元素是交点的外接矩形，(4,)数组
"""
# polygon可以不按点的顺序构建，但是必须使用convex_hull求交
if not isinstance(polygon, np.ndarray):
polygon = np.array(polygon)
polygon = polygon.reshape(-1, 2)
polygon = Polygon(polygon).convex_hull
box = Polygon(box).convex_hull
# boundary属性对应的LineString可以直接转为array对象
# 最后一个点与第一个点相同，予以去除
inters = polygon.intersection(box)
try:
intersections = np.array(inters.boundary)[:-1]
bounds = np.array(inters.bounds) # 外接矩形
except ValueError:
return None, None
return intersections, bounds