旋轉圖片和旋轉框（在線摳圖數據增強）

import os
import cv2
from PIL import Image
import torch
import random
import numpy as np
import math
import matplotlib.pyplot as plt

# 繞pointx,pointy逆時針旋轉
def Nrotate(angle,valuex,valuey,pointx,pointy):
  '''
  srx = (x-pointx)*cos(angle) + (y-pointy)*sin(angle)+pointx
  sry = (y-pointy)*cos(angle) - (x-pointx)*sin(angle)+pointy
  '''
  valuex = np.array(valuex)
  valuey = np.array(valuey)
  nRotatex = (valuex-pointx)*math.cos(angle) - (valuey-pointy)*math.sin(angle) + pointx
  nRotatey = (valuex-pointx)*math.sin(angle) + (valuey-pointy)*math.cos(angle) + pointy
  return nRotatex, nRotatey

# 繞pointx,pointy順時針旋轉
def Srotate(angle,valuex,valuey,pointx,pointy):
  valuex = np.array(valuex)
  valuey = np.array(valuey)
  sRotatex = (valuex-pointx)*math.cos(angle) + (valuey-pointy)*math.sin(angle) + pointx
  sRotatey = (valuey-pointy)*math.cos(angle) - (valuex-pointx)*math.sin(angle) + pointy
  return sRotatex,sRotatey


#旋轉框
def rotation(box,angle):
    '''
    :param box: [x1,y1,x2,y2]
    :param angle: for example 45
    :return:
    '''
    centerx = (box[0] + box[2]) / 2 #torch.FloatTensor([2.0]).cuda()
    centery = (box[1] + box[3]) / 2
    x1, y1 = Srotate(math.radians(angle), box[0], box[1], centerx, centery)
    x2, y2 = Srotate(math.radians(angle), box[0], box[3], centerx, centery)
    x3, y3 = Srotate(math.radians(angle), box[2], box[1], centerx, centery)
    x4, y4 = Srotate(math.radians(angle), box[2], box[3], centerx, centery)
    xmin = min(x1, x2, x3, x4)
    xmax = max(x1, x2, x3, x4)
    ymin = min(y1, y2, y3, y4)
    ymax = max(y1, y2, y3, y4)
    return [xmin,ymin,xmax,ymax]

if __name__=="__main__":
    img_position = '33955cf576299df088aa4b62afbdee6c-00818.jpg'
    # image = cv2.imread(img_position, cv2.IMREAD_COLOR)
    # img = cv2.cvtColor(image, cv2.COLOR_BGR2RGB)

    image=Image.open(img_position)
    image = image.rotate(15)

    plt.ion()
    fig = plt.figure(figsize=(5, 5))
    plt.imshow(image)
    currentAxis = plt.gca()

    roi=[512 ,250, 652,454]
    currentAxis.add_patch(plt.Rectangle((roi[0], roi[1]), roi[2]-roi[0],
                                        roi[3]-roi[1], fill=False,
                                        edgecolor='red', linewidth=1.5))

    # for epoch in range(10):
    #     angel=random.randint(1,90)
    roi = rotation(box=[512 ,250, 652,454],angle=15)
    currentAxis.add_patch(plt.Rectangle((roi[0], roi[1]), roi[2]-roi[0],
                                        roi[3]-roi[1], fill=False,
                                        edgecolor='orange', linewidth=1.5))




    # name = img_position.split('/')[-1]
    # target_dir ='./label_imgs/'
    # if not os.path.exists(target_dir):
    #     os.makedirs(target_dir)
    # plt.savefig(target_dir + name, format='jpg', transparent=True, dpi=300, pad_inches=0)

    plt.show()
    plt.pause(20)
    plt.close()

原圖：

 旋轉圖和框（取了最大外接矩陣用於摳圖）：