自学教程：python OpenCV学习笔记

pip install imutils

import cv2import imutils'''imutils.rotate第一个参数是翻转的图像，第二个参数的翻转角度函数还提供翻转中心的设置，但默认就是中心翻转。'''vc = cv2.VideoCapture(0)if vc.isOpened():  flag, frame = vc.read()  img = imutils.rotate(frame, 180)  # 图像翻转   cv2.imshow("frame", img)else:  flag = Falsewhile flag:  flag, frame = vc.read()  if frame is None:    break  if flag is True:    img = imutils.rotate(frame, 180)  # 图像翻转    cv2.imshow("frame", img)    if cv2.waitKey(10) == 27:      breakvc.release()cv2.destroyAllWindows()

from imutils import contoursimport cv2'''contours.sort_contours可选排序方式："left-to-right", "right-to-left", "top-to-bottom", "bottom-to-top"返回值为轮廓和外接矩形contours.label_contourcontours包内自带的画轮廓的函数，可以直接用，然后可以在图片上标出轮廓序号也可以直接使用cv2.drawContours直接画轮廓'''img = cv2.imread(r"D:/opencv-workspace/Opencv/test17--VScode/shapes.png")draw_img = img.copy()img_rect = img.copy()gray = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)img = cv2.Canny(gray, 10, 20)  # Canny边缘检测cnts, hierarchy = cv2.findContours(img, cv2.RETR_EXTERNAL, cv2.CHAIN_APPROX_NONE)  # 获得轮廓(cnts, boundingBoxes) = contours.sort_contours(cnts, "top-to-bottom")  # 对轮廓进行排序处理for (i, c) in enumerate(cnts):  sortedImage = contours.label_contour(draw_img, c, i, color=(240, 0, 159))# img_out = cv2.drawContours(draw_img, cnts, -1, (240, 0, 159), 2)# 根据boundingBoxes画外接矩形for (x, y, w, h) in boundingBoxes:  img_rect = cv2.rectangle(img_rect, (x, y), (x+w, y+h), (240, 0, 159), 2)cv2.imshow("top-to-bottom", sortedImage)cv2.imshow("rect", img_rect)cv2.waitKey(0)cv2.destroyAllWindows()

from imutils import contoursimport cv2'''contours.sort_contours可选排序方式："left-to-right", "right-to-left", "top-to-bottom", "bottom-to-top"返回值为轮廓和外接矩形contours.label_contourcontours包内自带的画轮廓的函数，可以直接用，然后可以在图片上标出轮廓序号也可以直接使用cv2.drawContours直接画轮廓'''img = cv2.imread(r"D:/opencv-workspace/Opencv/test17--VScode/shapes.png")draw_img = img.copy()img_rect = img.copy()gray = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)img = cv2.Canny(gray, 10, 20)  # Canny边缘检测cnts, hierarchy = cv2.findContours(img, cv2.RETR_EXTERNAL, cv2.CHAIN_APPROX_NONE)  # 获得轮廓(cnts, boundingBoxes) = contours.sort_contours(cnts, "top-to-bottom")  # 对轮廓进行排序处理for (i, c) in enumerate(cnts):  sortedImage = contours.label_contour(draw_img, c, i, color=(240, 0, 159))# img_out = cv2.drawContours(draw_img, cnts, -1, (240, 0, 159), 2)# 根据boundingBoxes画外接矩形for (x, y, w, h) in boundingBoxes:  img_rect = cv2.rectangle(img_rect, (x, y), (x+w, y+h), (240, 0, 159), 2)cv2.imshow("top-to-bottom", sortedImage)cv2.imshow("rect", img_rect)cv2.waitKey(0)cv2.destroyAllWindows()

'''使用下面这个函数进行转换，第一个参数填写要转换的图片，第二个参数填写cv2.COLOR_BGR2HSV'''cv2.cvtColor

import cv2import numpy as np'''cv2.inRange函数很简单，参数有三个第一个参数：hsv指的是原图第二个参数：lower_red指的是图像中低于这个lower_red的值，图像值变为0第三个参数：upper_red指的是图像中高于这个upper_red的值，图像值变为0而在lower_red～upper_red之间的值变成255'''# 阈值lower_green = np.array([50, 255, 255])upper_green = np.array([70, 255, 255])img = cv2.imread(r"D:/opencv-workspace/Opencv/test16--VScode/photo.jpg")img_hsv = cv2.cvtColor(img, cv2.COLOR_BGR2HSV)mask_green = cv2.inRange(img_hsv, lower_green, upper_green)cv2.imshow("img_or", mask_green)# 使用下面这个函数能显示原来的颜色。res_green = cv2.bitwise_and(img, img, mask=mask_green)cv2.imshow("img", res_green)cv2.waitKey(0)cv2.destroyAllWindows()

import cv2color = np.uint8([[[193, 189, 147]]])  # 参数填写BGR的值hsv = cv2.cvtColor(color, cv2.COLOR_BGR2HSV)print(hsv)  # 打印出来的数值就是对应的HSV值

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import cv2import numpy as npdef function(x):  lowH = cv2.getTrackbarPos("lowH", "img_666")  lowS = cv2.getTrackbarPos("lowS", "img_666")  lowV = cv2.getTrackbarPos("lowV", "img_666")  HighH = cv2.getTrackbarPos("HighH", "img_666")  HighS = cv2.getTrackbarPos("HighS", "img_666")  HighV = cv2.getTrackbarPos("HighV", "img_666")  # print(lowH, lowS, lowV, HighH, HighS, HighV)  lower = np.uint8([lowH, lowS, lowV])  upper = np.uint8([HighH, HighS, HighV])  mask = cv2.inRange(img_hsv, lower, upper)  res = cv2.bitwise_and(img, img, mask=mask)  cv2.imshow("img", res)img = cv2.imread(r"D:/opencv-workspace/Opencv/test16--VScode/test.jpg")img_hsv = cv2.cvtColor(img, cv2.COLOR_BGR2HSV)cv2.namedWindow("img_666")cv2.createTrackbar("lowH", "img_666", 0, 179, function)cv2.createTrackbar("lowS", "img_666", 0, 255, function)cv2.createTrackbar("lowV", "img_666", 0, 255, function)cv2.createTrackbar("HighH", "img_666", 0, 179, function)cv2.createTrackbar("HighS", "img_666", 0, 255, function)cv2.createTrackbar("HighV", "img_666", 0, 255, function)cv2.imshow("img", img)cv2.waitKey(0)cv2.destroyAllWindows()