如何用Python代码根据四个点坐标进行图片剪裁？

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使用了两种方法保存图片，OpenCV和PIL库。OpenCV保存速度快。代码如下：

pythonfrom PIL import Imageimport osimport cv2import timeimport matplotlib.pyplot as plt

def label2picture(cropImg, framenum, tracker): pathnew=E:\\img2\\ cv2.imwrite(pathnew + str(framenum) + .jpg, cropImg) time.sleep(0.1) plt.imshow(cropImg) plt.axis('off') plt.savefig(pathnew + str(framenum) + .png)

用了两种方法保存图片，opencv和Image，实践证明opencv非常快

from PIL import Image import os import cv2 import time import matplotlib.pyplot as plt def label2picture(cropImg,framenum,tracker): pathnew ="E:\\img2\\" # cv2.imshow("image", cropImg) # cv2.waitKey(1) if (os.path.exists(pathnew + tracker)): cv2.imwrite(pathnew + tracker+'\\'+framenum + '.jpg', cropImg,[int(cv2.IMWRITE_JPEG_QUALITY), 100]) else: os.makedirs(pathnew + tracker) cv2.imwrite(pathnew + tracker+'\\'+framenum + '.jpg', cropImg,[int(cv2.IMWRITE_JPEG_QUALITY), 100]) f = open("E:\\hypotheses.txt","r") lines = f.readlines() for line in lines: li = line.split(',') print(li[0],li[1],li[2],li[3],li[4],li[5]) filename = li[0]+'.jpg' img = cv2.imread("E:\\DeeCamp\\img1\\" + filename) crop_img = img[int(li[3][:-3]):(int(li[3][:-3]) + int(li[5][:-3])), int(li[2][:-3]):(int(li[2][:-3]) + int(li[4][:-3]))] # print(int(li[2][:-3]),int(li[3][:-3]),int(li[4][:-3]),int(li[5][:-3])) label2picture(crop_img, li[0], li[1]) # # # x,y,w,h = 87,158,109,222 # img = cv2.imread("E:\\DeeCamp\\img1\\1606.jpg") # # print(img.shape) # crop = img[y:(h+y),x:(w+x)] # cv2.imshow("image", crop) # cv2.waitKey(0) # img = Image.open("E:\\DeeCamp\\img1\\3217.jpg") # # cropImg = img.crop((x,y,x+w,y+h)) # cropImg.show() # img = Image.open("E:\\deep_sort-master\\MOT16\\train\\try1\\img1\\"+filename) # print(int(li[2][:-3]),(int(li[2][:-3])+int(li[4][:-3])), int(li[3][:-3]),(int(li[3][:-3])+int(li[5][:-3]))) # #裁切图片 # # cropImg = img.crop(region) # # cropImg.show() # framenum ,tracker= li[0],li[1] # pathnew = 'E:\\DeeCamp\\deecamp项目\\deep_sort-master\\crop_picture\\' # if (os.path.exists(pathnew + tracker)): # # 保存裁切后的图片 # plt.imshow(cropImg) # plt.savefig(pathnew + tracker+'\\'+framenum + '.jpg') # else: # os.makedirs(pathnew + tracker) # plt.imshow(cropImg) # plt.savefig(pathnew + tracker+'\\'+framenum + '.jpg')

补充知识：python实现固定区域截图，实现录屏截图

1、实现固定区域截图及保存

如果不设置区域默认是全屏保存

from PIL import ImageGrab # 参数说明 # 第一个参数 开始截图的x坐标 # 第二个参数 开始截图的y坐标 # 第三个参数 结束截图的x坐标 # 第四个参数 结束截图的y坐标 bbox = (760, 0, 1160, 1080) im = ImageGrab.grab(bbox) # 参数 保存截图文件的路径 im.save('zy.png')

2、实现屏幕的视频录制

可以用上面程序的bbox设置一下录屏区域

from time import sleep from PIL import ImageGrab m=int(input("输入录屏几分钟：")) m=m*60 n=1 while n<m: sleep(0.02) im=ImageGrab.grab() local=(r"%s.jpg"%(n)) im.save(local,'jpeg') n=n+1

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