Question

拍摄图像进行裁剪时，停止工作并停止

   while True:
      _, frame = cap.read()
      clone = frame.copy()
      cv2.namedWindow("image")
      cv2.setMouseCallback("image", shape_selection)
     # display the image and wait for a keypress
      cv2.imshow("image", frame)
      cv2.imshow("clone",clone)
      key = cv2.waitKey(1) & 0xFF

      if key == ord("r"):
        image = clone.copy()

      elif key == ord("c"):
        break

    if len(ref_point) == 2:
       crop_img = clone[ref_point[0][1]:ref_point[1][1], ref_point[0][0]:ref_point[1][0]]
       cv2.imshow("crop_img", crop_img)
       cv2.imwrite(filename='saved_img.jpg', img=crop_img)
       cv2.waitKey(0)
     # close all open windows
    cv2.destroyAllWindows()

这是我选择形状的功能 def shape_selection（事件，x，y，标志，参数）：＃获取对全局变量的引用全局ref_point，裁剪

  # if the left mouse button was clicked, record the starting
  # (x, y) coordinates and indicate that cropping is being
  # performed
  if event == cv2.EVENT_LBUTTONDOWN:
    ref_point = [(x, y)]
    cropping = True
    #cv2.imshow("image", clone)


  # check to see if the left mouse button was released
  elif event == cv2.EVENT_LBUTTONUP:
    # record the ending (x, y) coordinates and indicate that
    # the cropping operation is finished
    ref_point.append((x, y))
    cropping = False

    # draw a rectangle around the region of interest
    cv2.rectangle(clone, ref_point[0], ref_point[1], (0, 255, 0), 2)
    #cv2.imshow("image", clone)

Answer 1

import argparse
import cv2
from threading import Thread
# initialize the list of reference points and boolean indicating
# whether cropping is being performed or not
ref_point = []
cropping = False

def shape_selection(event, x, y, flags, param):
  # grab references to the global variables
  global ref_point, cropping

  # if the left mouse button was clicked, record the starting
  # (x, y) coordinates and indicate that cropping is being
  # performed
  if event == cv2.EVENT_LBUTTONDOWN:
    ref_point = [(x, y)]
    cropping = True
    #cv2.imshow("image", clone)


  # check to see if the left mouse button was released
  elif event == cv2.EVENT_LBUTTONUP:
    # record the ending (x, y) coordinates and indicate that
    # the cropping operation is finished
    ref_point.append((x, y))
    cropping = False
    crop_img = clone[ref_point[0][1]:ref_point[1][1], ref_point[0][0]:ref_point[1][0]]
    cv2.imshow("crop_img", crop_img)
    cv2.imwrite(filename='saved_img.jpg', img=crop_img)
    # draw a rectangle around the region of interest
    cv2.rectangle(clone, ref_point[0], ref_point[1], (0, 255, 0), 2)
    #cv2.imshow("image", clone)

# load the image, clone it, and setup the mouse callback function
cap = cv2.VideoCapture(0)


# keep looping until the 'q' key is pressed
while True:
  _, frame = cap.read()
  clone = frame.copy()
  cv2.namedWindow("image")
  #cv2.setMouseCallback("image", shape_selection)
  # display the image and wait for a keypress
  cv2.imshow("image", frame)
  cv2.imshow("clone",clone)
  key = cv2.waitKey(1) & 0xFF
cv2.destroyAllWindows()

为什么当我在实时网络摄像头中拍摄感兴趣的区域时，相机会停下来？

1 个答案: