使用按鍵觸發事件？

Question

我試圖讓我的程序僅在按下一個鍵時拍攝 8 張照片，但我找不到解決方案。 我嘗試了鍵盤 package 並且每當我按下鍵時都會拋出錯誤。 順便說一下，這是我的代碼-

import numpy as np
import cv2
import time
cap = cv2.VideoCapture('morning.mp4')

img_counter = 0
start_time = time.time()
x=0


while(cap.isOpened()):
    ret, frame = cap.read()

    gray = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)

    cv2.imshow('frame',gray)
    if cv2.waitKey(47) & 0xFF == ord('q'):
        break
    #here is where the image capturing comes into play    
    if time.time() - start_time > 14: #<---- Check if 15 sec passed
        img_name = "frame_{}.png".format(x)
        cv2.imwrite(img_name, frame)
        print("{} written!".format(img_counter))
        start_time = time.time()
        x += 1
    img_counter += 1
    if x == 8:
        break  

cap.release()
cv2.destroyAllWindows()

在評論“#這里是圖像捕獲發揮作用的地方”之后，直到 break 語句是我為視頻拍照的地方，我想用按鍵觸發那部分代碼。 知道我應該如何 go 嗎？

Answer 1

問題是您在按鍵后中斷了while循環。 您應該使用一些 boolean 變量來指示腳本何時應該捕獲圖像。

代碼：

import numpy as np
import cv2
import time
cap = cv2.VideoCapture('morning.mp4')

img_counter = 0
start_time = time.time()
x=0
capture_images = False

while(cap.isOpened()):
    ret, frame = cap.read()

    gray = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)

    cv2.imshow('frame',gray)
    if cv2.waitKey(47) & 0xFF == ord('q'):
        capture_images = True
    if capture_images:
        #here is where the image capturing comes into play    
        if time.time() - start_time > 14: #<---- Check if 15 sec passed
            img_name = "frame_{}.png".format(x)
            cv2.imwrite(img_name, frame)
            print("{} written!".format(img_counter))
            start_time = time.time()
            x += 1
        img_counter += 1
        if x == 8:
            break  

cap.release()
cv2.destroyAllWindows()