IoUの0.1～0.9を図にしてみた ref: https://qiita.com/ak11/items/8e0f42f358c1f822df27

plot_iou.py

import matplotlib
import matplotlib.pyplot as plt

import numpy as np

for i, iou in enumerate(np.linspace(1, 0, 11)):
    # 　 ↓t
    # □□□
    # □□□
    # □□■□□
    # 　　□□□
    # 　　□□□

    # inter = (1 - t) ** 2
    # union = 2 - inter
    # iou = inter / union
    # https://www.wolframalpha.com/input/?dataset=&i=Solve%5Bu+%3D%3D+(1+-+t)%5E2+%2F+(2+-+(1+-+t)%5E2)+%26%26+0+<%3D+t+%26%26+t+<%3D+1+%26%26+0+<%3D+u+%26%26+u+<%3D+1,+t%5D
    # → t = 1 - sqrt(2) sqrt(u/(1 + u))
    t = 1 - np.sqrt(2 * iou / (1 + iou))
    print(f'#{i} iou={iou:.2f}, offset={t:.2f}')

    fig = plt.figure()
    ax = plt.axes()
    ax.add_patch(matplotlib.patches.Rectangle(xy=(0 / 2, 0.5 + 0 / 2), width=0.5, height=0.5, color='#9999ff77'))
    ax.add_patch(matplotlib.patches.Rectangle(xy=(t / 2, 0.5 - t / 2), width=0.5, height=0.5, color='#99ff9977'))
    ax.set_aspect('equal')
    plt.savefig(f'#{i} iou={iou:.2f}, offset={t:.2f}.png')
    plt.close()