问题描述
我有这个脚本可以从网络摄像头捕获图像，但是它没有保存任何图像，我不知道为什么.我收到此错误"回溯(最近通话一次):在第26行中输入文件"C:/Users/Iram/.PyCharmCE2019.3/config/scratches/scratch_5.py"灰色= cv2.cvtColor(img_，cv2.COLOR_BGR2GRAY)cv2.error:OpenCV(4.2.0)C:\ projects \ opencv-python \ opencv \ modules \ imgproc \ src \ color.cpp:182:error:(-215:Assertion failed)！_src.empty()在函数中'cv :: cvtColor'[WARN:0]全局C:\ projects \ opencv-python \ opencv \ modules \ videoio \ src \ cap_msmf.cpp(674)SourceReaderCB :: ~~ SourceReaderCB终止异步回调"
I have this script to capture images from webcam, but it is not saving any image, I donot know why. I am getting this error"Traceback (most recent call last): File "C:/Users/Iram/.PyCharmCE2019.3/config/scratches/scratch_5.py", line 26, in gray = cv2.cvtColor(img_, cv2.COLOR_BGR2GRAY)cv2.error: OpenCV(4.2.0) C:\projects\opencv-python\opencv\modules\imgproc\src\color.cpp:182: error: (-215:Assertion failed) !_src.empty() in function 'cv::cvtColor'[ WARN:0] global C:\projects\opencv-python\opencv\modules\videoio\src\cap_msmf.cpp (674) SourceReaderCB::~SourceReaderCB terminating async callback"
我的代码是
import cv2
import datetime
i = 1
key = cv2.waitKey(1)
webcam = cv2.VideoCapture(0)
while True:
try:
check, frame = webcam.read()
print(check) # prints true as long as the webcam is running
print(frame) # prints matrix values of each framecd
cv2.imshow("Capturing", frame)
key = cv2.waitKey(1)
if key == ord('s'):
cv2.imwrite(filename='saved_img.jpg,%Y-%b-%d %H:%M:%S', img=frame)
#print('Timestamp: {:%Y-%b-%d %H:%M:%S}'.format(datetime.datetime.now()))
i += 1
print('%i')
# webcam.release()
img_new = cv2.imread('saved_img.jpg,%Y-%b-%d %H:%M:%S', cv2.IMREAD_GRAYSCALE)
# cv2.imshow("Captured Image", img_new)
# cv2.waitKey(1925)
print("Processing image...")
img_ = cv2.imread('saved_img.jpg,%Y-%b-%d %H:%M:%S', cv2.IMREAD_ANYCOLOR)
print("Converting RGB image to grayscale...")
gray = cv2.cvtColor(img_, cv2.COLOR_BGR2GRAY)
print("Converted RGB image to grayscale...")
print("Resizing image to 28x28 scale...")
img_ = cv2.resize(gray, (28, 28))
print("Resized...")
img_resized = cv2.imwrite(filename='saved_img-final.jpg', img=img_)
print("Image saved!")
elif key == ord('q'):
print("Turning off camera.")
webcam.release()
print("Camera off.")
print("Program ended.")
cv2.destroyAllWindows()
break
except(KeyboardInterrupt):
print("Turning off camera.")
webcam.release()
print("Camera off.")
print("Program ended.")
cv2.destroyAllWindows()
camera.release()
break
camera.release()
cv2.destroyAllWindows()
有人可以帮我吗?
推荐答案
错误的根源是您使用的文件名带有冒号 :字符.
The source of the error is that you are using file name with colon : character.
cv2.imwrite(filename='saved_img.jpg,%Y-%b-%d %H:%M:%S', img=frame)
包含冒号的文件名是非法的.
File name containing a colon character is illegal.
- 图像(框架)未写入文件.
- 读取图像
img_ = cv2.imread('saved_img.jpg，％Y-％b-％d％H:％M:％S'，cv2.IMREAD_ANYCOLOR)返回没有. - 将
None值传递给cv2.cvtColor会引发OpenCV异常.
- The image (frame) is not written to the file.
- Reading the image
img_ = cv2.imread('saved_img.jpg,%Y-%b-%d %H:%M:%S', cv2.IMREAD_ANYCOLOR)returnsNone. - Passing
Nonevalue tocv2.cvtColorraise an OpenCV exception.
建议的解决方法:
- 使用有效文件名，例如:
file_name = datetime.datetime.now().strftime('％Y-％m-％d_％H-％M-％S.jpg') - 读写时使用变量
file_name. - 我还建议在使用
frame之前，先验证check是否为True.
- Use valid file name like:
file_name = datetime.datetime.now().strftime('%Y-%m-%d_%H-%M-%S.jpg') - Use the variable
file_namewhen reading and writing. - I am also suggesting to verify that
checkisTruebefore usingframe.
我创建了一个示例代码进行测试.
该代码生成合成视频文件，并从生成的文件而不是从摄像机读取帧.
I created a sample code for testing.
The code generates synthetic video file, and read frames from the generated file instead of from camera.
这是测试代码:
import numpy as np
import cv2
import datetime
intput_filename = 'input_vid.avi'
# Generate synthetic video files to be used as input:
###############################################################################
width, height, n_frames = 640, 480, 100 # 100 frames, resolution 640x480
# Use motion JPEG codec (for testing)
synthetic_out = cv2.VideoWriter(intput_filename, cv2.VideoWriter_fourcc(*'MJPG'), 25, (width, height))
for i in range(n_frames):
img = np.full((height, width, 3), 60, np.uint8)
cv2.putText(img, str(i+1), (width//2-100*len(str(i+1)), height//2+100), cv2.FONT_HERSHEY_DUPLEX, 10, (30, 255, 30), 20) # Green number
synthetic_out.write(img)
synthetic_out.release()
###############################################################################
i = 1
key = cv2.waitKey(1)
# Read video from file instead of from camera (for testing)
webcam = cv2.VideoCapture(intput_filename)
while True:
try:
check, frame = webcam.read()
print(check) # prints true as long as the webcam is running
if check:
print(frame) # prints matrix values of each frame
cv2.imshow("Capturing", frame)
if key == ord('s'):
file_name = datetime.datetime.now().strftime('%Y-%m-%d_%H-%M-%S.jpg')
cv2.imwrite(file_name, img=frame)
#print('Timestamp: {:%Y-%b-%d %H:%M:%S}'.format(datetime.datetime.now()))
i += 1
print(str(i))
# webcam.release()
img_new = cv2.imread(file_name, cv2.IMREAD_GRAYSCALE)
# cv2.imshow("Captured Image", img_new)
# cv2.waitKey(1925)
print("Processing image...")
img_ = cv2.imread(file_name, cv2.IMREAD_ANYCOLOR)
print("Converting RGB image to grayscale...")
gray = cv2.cvtColor(img_, cv2.COLOR_BGR2GRAY)
print("Converted RGB image to grayscale...")
print("Resizing image to 28x28 scale...")
img_ = cv2.resize(gray, (28, 28))
print("Resized...")
img_resized = cv2.imwrite(filename='saved_img-final.jpg', img=img_)
print("Image saved!")
#key = cv2.waitKey(1)
key = cv2.waitKey(100) # Wait 100 msec (just for testing).
if key == ord('q'):
print("Turning off camera.")
print("Camera off.")
print("Program ended.")
break
except(KeyboardInterrupt):
print("Turning off camera.")
print("Camera off.")
print("Program ended.")
break
webcam.release()
cv2.destroyAllWindows()
这篇关于从网络摄像头拍摄图像的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！