如何在Python中删除图像的背景

我有一个包含全角人类图像的数据集，我想删除这些图像中的所有背景，只留下全角人物，

我的问题：

有没有Python代码可以做到这一点？

我是否需要每次都指定人员对象的坐标？

这是使用 Python/OpenCV 的一种方法。

• 读取输入
• 转换为灰色
• 阈值和反转作为掩模
• 可选择应用形态学来清理任何无关的斑点
• 边缘抗锯齿
• 将输入的副本转换为 BGRA 并插入遮罩作为 Alpha 通道
• 保存结果

Input:

import cv2
import numpy as np

# load image
img = cv2.imread('person.png')

# convert to graky
gray = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)

# threshold input image as mask
mask = cv2.threshold(gray, 250, 255, cv2.THRESH_BINARY)[1]

# negate mask
mask = 255 - mask

# apply morphology to remove isolated extraneous noise
# use borderconstant of black since foreground touches the edges
kernel = np.ones((3,3), np.uint8)
mask = cv2.morphologyEx(mask, cv2.MORPH_OPEN, kernel)
mask = cv2.morphologyEx(mask, cv2.MORPH_CLOSE, kernel)

# anti-alias the mask -- blur then stretch
# blur alpha channel
mask = cv2.GaussianBlur(mask, (0,0), sigmaX=2, sigmaY=2, borderType = cv2.BORDER_DEFAULT)

# linear stretch so that 127.5 goes to 0, but 255 stays 255
mask = (2*(mask.astype(np.float32))-255.0).clip(0,255).astype(np.uint8)

# put mask into alpha channel
result = img.copy()
result = cv2.cvtColor(result, cv2.COLOR_BGR2BGRA)
result[:, :, 3] = mask

# save resulting masked image
cv2.imwrite('person_transp_bckgrnd.png', result)

# display result, though it won't show transparency
cv2.imshow("INPUT", img)
cv2.imshow("GRAY", gray)
cv2.imshow("MASK", mask)
cv2.imshow("RESULT", result)
cv2.waitKey(0)
cv2.destroyAllWindows()

透明结果：