【python】获取大图片中两个点的具体坐标，并将图无损裁剪下来

妖狐艹你老母 2022-11-15 11:48 14阅读 0赞

### 文章目录 ###

*  一、原始图片
 *  二、取点的方法
 *  三、另一种取点的方法
 *  四、取点并裁剪图片
 *  参考
 *  附录

# 一、原始图片 #

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L21pcmFjbGVvYQ_size_16_color_FFFFFF_t_70]

# 二、取点的方法 #

*  `point.py`

from PIL import Image
    from pylab import *
    
    
    def point(img_path):
        Image.MAX_IMAGE_PIXELS = 100000000000
        # im = array(Image.open('best_result.png'))
        im = array(Image.open(img_path))
        imshow(im)
        print('Please click 2 points')
        x = ginput(2)
        # show()
        return x
    
    
    if __name__ == '__main__':
        x = point('cut_orchard2.png')
        print('you clicked:', x)

# 三、另一种取点的方法 #

*  注意方法二展示的图片是原比例的，对于大图不太方便，推荐上一种方法。
 *  `point1.py`

import cv2
    import numpy as np
    
    img = cv2.imread('C:\\Users\\mimi\\Desktop\\1.jpg')
    a = []
    b = []
    
    
    def on_EVENT_LBUTTONDOWN(event, x, y, flags, param):
        if event == cv2.EVENT_LBUTTONDOWN:
            xy = "%d,%d" % (x, y)
            a.append(x)
            b.append(y)
            cv2.circle(img, (x, y), 1, (255, 0, 0), thickness=-1)
            cv2.putText(img, xy, (x, y), cv2.FONT_HERSHEY_PLAIN,
                        1.0, (0, 0, 0), thickness=1)
            cv2.imshow("image", img)
    
    
    cv2.namedWindow("image")
    cv2.setMouseCallback("image", on_EVENT_LBUTTONDOWN)
    cv2.imshow("image", img)
    cv2.waitKey(0)
    print(a[0], b[0])
    
    img[b[0]:b[1], a[0]:a[1], :] = 0  # 注意是 行，列（y轴的，X轴）
    cv2.imshow("image", img)
    cv2.waitKey(0)
    print(a, b)

# 四、取点并裁剪图片 #

*  代码
 *  此处引用point函数

from point import point
    import cv2
    import numpy as np
    
    
    # 输入两个对角点的坐标，裁剪图片
    def cut_pic(img_path, point_list):
        [(x1, y1), (x2, y2)] = point_list
        img = cv2.imread(img_path)
        # img = np.array(img)
        # 新图片
        print(img.shape)
        # 此处注意opencv的顺序是先h，后w，然后c。
        img_new = img[y1:y2, x1:x2, :]
        cv2.imwrite("save.png", img_new)
    
    
    if __name__ == '__main__':
        # img_path = "xiatian_qingwa.jpg"
        img_path = "best_result1.png"
        # ----------------------------
        # 得到两个对角点的坐标
        point_two = point(img_path)
        point_two_new = []
        # 清空列表
        # point_two.clear()
        for i in point_two:
            i_new = list(map(int, i))
            point_two_new.append(i_new)
        # [(4393, 426), (12439, 12439)]
        print(point_two_new)
        # ----------------------------
        # point_two_new = [(4393, 426), (12439, 12439)]
        cut_pic(img_path, point_two_new)

*  控制台输出：

Please click 2 points
    [(242, 177), (340, 340)]
    (512, 820, 3)

*  得到青蛙的截图：  
    ![在这里插入图片描述][20210331232946700.png]

# 参考 #

[如果显示图片过大报错应对方法][Link 1]

# 附录 #

*  注意关闭下面的勾，否者PIL无法正常工作  
    ![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L21pcmFjbGVvYQ_size_16_color_FFFFFF_t_70 1]

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L21pcmFjbGVvYQ_size_16_color_FFFFFF_t_70]: /images/20221022/fedf1adb8ffc44c7a2a5d9c78add4061.png
[20210331232946700.png]: https://img-blog.csdnimg.cn/20210331232946700.png
[Link 1]: https://blog.csdn.net/u013066730/article/details/90022278
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L21pcmFjbGVvYQ_size_16_color_FFFFFF_t_70 1]: https://img-blog.csdnimg.cn/20210401110100964.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L21pcmFjbGVvYQ==,size_16,color_FFFFFF,t_70