代码笔记-OpenCV3-计算机视觉-python语言实现(第二版)

 1 import time
 2 
 3 num = 2-1-3+3
 4 print(num)
 5 # 打开显示图像
 6 if num == 1:
 7     # 读取图像，支持 bmp、jpg、png、tiff 等常用格式
 8     img = cv2.imread(r"D:\UIAUTO\trainingSet\simpleGeometricFigure\1.jpg")
 9     # 创建窗口并显示图像
10     cv2.namedWindow("Image")
11     cv2.imshow("Image", img)
12     # 刷新窗口
13     cv2.waitKey(0)
14     # 释放窗口
15     cv2.destroyAllWindows()

 1 # 2.1.2 图像与原始字节之间的转换
 2 # 随机生成两个图像，他们位于脚本所在的目录，图像名为RandomGray.png 和 RandomColor.png.
 3 if num == 2-1-2:
 4     randomByteArray = bytearray(os.urandom(120000))
 5     flatNumpyArray = numpy.array(randomByteArray)
 6 
 7     grayImage = flatNumpyArray.reshape(300, 400)
 8     cv2.imwrite(‘RandomGray.png‘, grayImage)
 9     bgrImage = flatNumpyArray.reshape(100, 400, 3)
10     cv2.imwrite(‘RandomColor.png‘, bgrImage)

 1 # 2.1.3 使用numpy.array访问图像数据
 2 if num == 2-1-3+1:
 3     img = cv2.imread(r"D:\UIAUTO\trainingSet\simpleGeometricFigure\1.jpg")
 4     # 将jpg图像在左上宽50高50区域像素,处转化为红色像素
 5     for a in range(0, 50):
 6         for b in range(0, 50):
 7             img[a, b] = [2, 3, 255]
 8     cv2.imwrite("1.jpg", img)
 9 
10     # item(x,y,通道索引0-2)
11     print("x:49 y:49 R:", img.item(49, 49, 0))
12     print("x:49 y:49 G:", img.item(49, 49, 1))
13     print("x:49 y:49 B:", img.item(49, 49, 2))
14 
15     # 把区域像素设置为白色,不改变读入的图片像素
16     for x in range(0, 50):
17         for y in range(0, 50):
18             img.itemset((x, y, 0), 250)
19             img.itemset((x, y, 1), 250)
20             img.itemset((x, y, 2), 250)
21     cv2.imwrite("21.jpg", img)

1 # 像素变换
2 # 这种变化速度优于上面的循环变换
3 if num == 2-1-3+2:
4     img = cv2.imread(r"D:\PythonWorkspace\deep leanr\venv\21.jpg")
5     img[0:200:1, 0:200:1, 1] = 2
6     cv2.imwrite(‘22.jpg‘, img)
7     time.sleep(2)

 1 # 图像区域拷贝
 2 if num == 2-1-3+3:
 3     img = cv2.imread(r‘D:\PythonWorkspace\deep leanr\venv\18151.jpg‘)
 4     my_roi = img[0:100:1, 0:100:1]
 5     img[300:400:1, 300:400:1] = my_roi
 6     cv2.namedWindow("Image")
 7     cv2.imshow("Image", img)
 8     cv2.waitKey(0)  # 刷新时间
 9     cv2.destroyAllWindows()  # 释放窗口
10     print(img.shape)  # 返回一个数组: [宽度,高度,通道数]
11     print(img.size)  # 像素大小
12     print(img.dtype)  # 图像的数据类型

 1 import cv2
 2 
 3 
 4 # I/O视频文件
 5 if num == 1:
 6     videoCapture = cv2.VideoCapture(‘MyInputVid.avi‘)
 7     fps = videoCapture.get(cv2.CAP_PROP_FPS)
 8     size = (int(videoCapture.get(cv2.CAP_PROP_FRAME_WIDTH)),
 9             int(videoCapture.get(cv2.CAP_PROP_FRAME_HEIGHT))
10             )
11     videoWriter = cv2.VideoWriter(‘MyOutputVid.avi‘, cv2.VideoWriter_fourcc(‘I‘, ‘4‘, ‘2‘, ‘0‘), fps, size)
12     success, frame = videoCapture.read()
13     while success:  # Loop until there are no more frames.
14         videoWriter.write(frame)
15         success, frame = videoCapture.read()

 1 if num == 2:
 2     cameraCapture = cv2.VideoCapture(0)
 3     fps = 30  # an assumption
 4     size = (
 5         int(cameraCapture.get(cv2.CAP_PROP_FRAME_WIDTH)),
 6         int(cameraCapture.get(cv2.CAP_PROP_FRAME_HEIGHT))
 7     )
 8     videoWriter = cv2.VideoWriter(‘MyOutputVid.avi‘, cv2.VideoWriter_fourcc(‘I‘, ‘4‘, ‘2‘, ‘0‘), fps, size)
 9 
10     success, frame = cameraCapture.read()
11     numFrameRemaining = 10 * fps - 1
12     while success and numFrameRemaining > 0:
13         videoWriter.write(frame)
14         success, frame = cameraCapture.read()
15         numFrameRemaining -= 1
16     cameraCapture.release()

 1 # 在窗口显示摄像头帧
 2 # waitKey()的参数为等待键盘触发的时间, 单位为毫秒, 其返回值是-1(表示没有键被按下)或ASCLL码.
 3 # 另外,python提供了一个标准函数ord(), 该函数可以将字符转换为ASCLL码. 例如, 输入ord(‘a‘)会返回97
 4 
 5 # OpenCV的窗口函数和waitKey()函数互相依赖.OpenCV的窗口只有在调用waitKey()函数时才会更新, waitKey()函数只有在OpenCV
 6 # 窗口成为活动窗口时,才能捕获输入信息.
 7 
 8 # 鼠标回调函数setMouseCallback()有五个参数, 如前面的实列代码所示.param为可选参数,
 9 # 它是setMouseCallback()函数的第三个参数, 默认情况下, 该参数是0. 回调事件参数可以取如下的值, 他们分别对应不同的鼠标事件.
10 #   cv2.EVENT_MOUSEMOVE: 该事件对应鼠标移动
11 #   cv2.EVENT_LBUTTONDOWN: 鼠标左键按下
12 #   cv2.EVENT_RBUTTONDOWN: 鼠标右键按下
13 #   cv2.EVENT_MBUTTONDOWN: 鼠标中间键按下
14 #            _LBUTTONUP: 鼠标左键松开
15 #            _RBUTTONUP:
16 #            _MUBTTONUP:
17 #            _LBUTTONDBLCLK: 双击鼠标左键
18 #            _RBUTTONDBLCLK:
19 #            _MBUTTONDBLCLK:
20 # 鼠标回调的标志参数可能是一下事件的按位组合
21 #   cv2.EVENT_FLAG_LUBTTON: 该事件对应按下鼠标左键
22 #   cv2.EVENT_FLAG_RBUTTON: 该事件对应按下鼠标右键
23 #   cv2.EVENT_FLAG_MBUTTON: 该事件对应按下鼠标中间键
24 #            _FLAG_CTRLKEY: 按下Ctrl键
25 #            _FLAG_SHIFTKEY: 按下Shift键
26 #            _FLAG_ALTKEY: 按下Alt键
27 # 然而,OpenCV不提供任何处理窗口事件的方法. 例如, 当单击窗口的关闭按钮时, 并不能关闭应用程序.
28 # 由于OpenCV有限的事件处理能力和GUI处理能力, 许多开发人员更喜欢将OpenCV集成到其他应用程序框架中.
29 if num == 3:
30     clicked = False
31     def onMouse(event, x, y, flags, param):
32         global clicked
33         if event == cv2.EVENT_LUBTTONUP:
34             clicked = True
35     cameraCapture = cv2.VideoCapture(0)
36     cv2.namedWindow(‘MyWindow‘)
37     cv2.setMouseCallback(‘MyWindow‘, onMouse)
38 
39     print(‘Showing camera feed. Click window or press any key to stop‘)
40     success, frame = cameraCapture.read()
41     while success and cv2.waitKey(1) == -1 and not clicked:
42         cv2.imshow(‘MyWindow‘, frame)
43         success, frame = cameraCapture.read()
44 
45     cv2.destroyWindow(‘MyWindow‘)
46     cameraCapture.release()