python - 使用原始点列表在Python/cv2中查找重叠矩形的区域

我有一个矩形的坐标x1，y1，x2，y2和其他矩形的其他坐标列表。

我想比较一个已经拥有的值和其他值，看它们是否重叠得比原始矩形的50%多。

我检查了其他资源，但是仍然可以解决:

https://codereview.stackexchange.com/questions/151309/check-if-two-rectangles-overlap

https://codereview.stackexchange.com/questions/31352/overlapping-rectangles

最佳答案

首先让我们将问题简化为一个维度:

您有一个区间A = [a0, a1]，并想找出另一个区间B = [b0, b1]与它相交多少。我将用A表示=，用B表示-。

有6种可能的情况:

A包含B，intersection = b1 - b0

a0  b0  b1  a1
==============
    ------

B包含A，intersection = a1 - a0

b0  a0  a1  b1
    ======
--------------

B从左边与A相交，intersection = b1 - a0

b0  a0  b1  a1
    ==========
----------

B从右边与A相交，intersection = a1 - b0

a0  b0  a1  b1
==========
    ----------

B在A，intersection = 0的左侧

b0  b1  a0  a1
        ======
------

B在A，intersection = 0的右侧

a0  a1  b0  b1
======
        ------

基于此，我们可以定义一个函数，给定两个间隔A = [a0, a1]和B = [b0, b1]，该函数返回它们相交的数量:

def calculateIntersection(a0, a1, b0, b1):
    if a0 >= b0 and a1 <= b1: # Contained
        intersection = a1 - a0
    elif a0 < b0 and a1 > b1: # Contains
        intersection = b1 - b0
    elif a0 < b0 and a1 > b0: # Intersects right
        intersection = a1 - b0
    elif a1 > b1 and a0 < b1: # Intersects left
        intersection = b1 - a0
    else: # No intersection (either side)
        intersection = 0

    return intersection

这几乎就是您需要的一切。要找出两个矩形相交的数量，您只需要在X和Y轴上都执行此函数，并将其相乘即可得到相交区域:

# The rectangle against which you are going to test the rest and its area:
X0, Y0, X1, Y1, = [0, 0, 10, 10]
AREA = float((X1 - X0) * (Y1 - Y0))

# Rectangles to check
rectangles = [[15, 0, 20, 10], [0, 15, 10, 20], [0, 0, 5, 5], [0, 0, 5, 10], [0, 5, 10, 100], [0, 0, 100, 100]]

# Intersecting rectangles:
intersecting = []

for x0, y0, x1, y1 in rectangles:
    width = calculateIntersection(x0, x1, X0, X1)
    height = calculateIntersection(y0, y1, Y0, Y1)
    area = width * height
    percent = area / AREA

    if (percent >= 0.5):
        intersecting.append([x0, y0, x1, y1])

结果将是:

[15, 0, 20, 10]在X轴上不相交，所以width = 0。

[0, 15, 10, 20]在Y轴上不相交，因此height = 0。

[0, 0, 5, 5]仅与25%相交。

[0, 0, 5, 10]与50%相交，并将其添加到intersecting中。

[0, 5, 10, 100]与50%相交，并将其添加到intersecting中。

[0, 0, 100, 100]与100%相交，并将其添加到intersecting中。