crop.py

import numpy as np
import cv2
from PIL import Image
import shutil

'''
_crop
    裁剪
    取中心的80%部分，并进行随机偏移
    (可能将目标对象裁减掉，因此采用手工重新标注)

    Take 80% of the center and do random migration
    (Target objects may be trimmed, so manual reannotations are used)
'''
def crop(img):
    size = img.shape[:2]
    kernel_size = list(map(lambda x: int(x*0.8), size))
    shift_min, shift_max = -50, 50
    shift_size = [np.random.randint(shift_min, shift_max), np.random.randint(shift_min, shift_max)]

    crop_img = img[
        (size[0]-kernel_size[0])//2+shift_size[0]:(size[0]-kernel_size[0])//2+kernel_size[0]+shift_size[0],
        (size[1]-kernel_size[1])//2+shift_size[1]:(size[1]-kernel_size[1])//2+kernel_size[1]+shift_size[1]
    ]
    
    return Image.fromarray(np.uint8(crop_img))