Lossy compression in jpg format (sacrificing image quality)
img = cv2.imread("E:/code/conputer_visual/data/0.jpg", 1)
#param2为压缩参数，50代表压缩比例，该值范围在0-100，越小代表压缩力度越大
cv2.imwrite("E:/code/conputer_visual/data/2.jpg", img, [cv2.IMWRITE_JPEG_QUALITY, 50])
Lossless compression in png format
img = cv2.imread("E:/code/conputer_visual/data/0.jpg", 1)
#param2为压缩参数，50代表压缩比例，该值范围在0-9，越小代表压缩力度越小
cv2.imwrite("E:/code/conputer_visual/data/3.png", img, [cv2.IMWRITE_PNG_COMPRESSION, 9])