cv2.putText 在向图像中添加文本信息时，如果在待添加的文本中含有换行转义符，一般它是无法正确处理的：

cv2.putText(img, "This is \n some text", (50,50), cv2.FONT_HERSHEY_SIMPLEX, .6, (0, 255, 0), 1, 2)

一种解决方案如下：

img = cv2.imread('boat.png')
text = 'This is \nsome text'
y0, dy = 50, 25
for i, txt in enumerate(text.split('\n')):
    y = y0+i*dy
    cv2.putText(img, txt, (50, y), cv2.FONT_HERSHEY_SIMPLEX,  .6, (0, 255, 0), 1, 2)
cv2.imshow('img', img)
cv2.waitKey(0)

https://blog.csdn.net/lanchunhui/article/details/71229235