System information (version)

• OpenCV => 4.2.0.34 / 4.5.1.48 (python)
• Operating System / Platform => Ubuntu 20.04 (linux 5.8.0-48-generic), x86_64
• Compiler => N/A

Detailed description

OpenCV is throwing an assertion error when running rotatedRectangleIntersection:

cv2.error: OpenCV(4.2.0) /io/opencv/modules/imgproc/src/intersection.cpp:271: error: (-215:Assertion failed) fabs(normL2Sqr<float>(intersection[minI] - intersection[minJ]) - minD) < 1e-6 in function 'rotatedRectangleIntersection'

Issue has been discussed on the OpenCV forum here.

TL;DR
Assertion error is solved by applying an offset to bring the rectangles closer to the (0, 0), which implies that maybe it is linked to the rectangle being "far away".

Steps to reproduce

import cv2 as cv
import numpy as np


def box(box):
    return ((box[0], box[1]), (box[2], box[3]), box[4])


box_1 = np.array([ 246805.033  , 4002326.94   ,      26.40587,       6.20026,     -62.10156])
box_2 = np.array([ 246805.122  , 4002326.59   ,      27.4821 ,       8.5361 ,     -56.33761])

try:
    print(cv.rotatedRectangleIntersection(box(box_1), box(box_2)))  # Assertion error
except Exception as e:
    print(e)

offset = (246805, 4002326, 0, 0, 0)

box_1 -= offset
box_2 -= offset

print(cv.rotatedRectangleIntersection(box(box_1), box(box_2)))  # that works

Issue submission checklist

• I report the issue, it's not a question
• I checked the problem with documentation, FAQ, open issues,
  forum.opencv.org, Stack Overflow, etc and have not found solution
• I updated to latest OpenCV version and the issue is still there
• There is reproducer code and related data files: videos, images, onnx, etc