利用 numpy 删除图片白色边框

crop_image_rim.py

#!/usr/bin/env python
# coding: utf-8
import numpy as np
from PIL import Image


# 得到需要裁剪边框的距离
def remove_image_rim(np_img, boundary=0.8):
    _np_img = np_img
    h, w, c = np_img.shape
    endpoint = 0
    half_h = h - int(h / 2)
    for i, row in enumerate(np_img[half_h:h]):

        light = np.count_nonzero(row >= [250, 250, 250])
        dark = np.count_nonzero(row <= [5, 5, 5])
        if light / w > boundary or dark / w > boundary:
            endpoint = i
            break
    if endpoint == 0:
        return np_img
    rim = range(endpoint + half_h, h)
    np_img = np.delete(np_img, rim, axis=0)
    return np_img

im = Image.open("photo.jpg")

np_img = np.array(im)
np_img = remove_image_rim(np_img)

# 旋转至 90 度
np_img = np.rot90(np_img)
np_img = remove_image_rim(np_img)

# 旋转至 180 度
np_img = np.rot90(np_img)
np_img = remove_image_rim(np_img)


# 旋转至 270 度
np_img = np.rot90(np_img)
np_img = remove_image_rim(np_img)


# 恢复到初始位置
np_img = np.rot90(np_img)


im = Image.fromarray(np_img)
im.save("photo2.jpg")