I'm struggling with a problem to send a cv2 videostream (webcam) to a server (which shall be used later for face recognition).

I keep getting the following error for the server:

Traceback (most recent call last):File "server.py", line 67, in <module>small_frame = cv2.resize(frame, (0, 0), fx=0.25, fy=0.25)
cv2.error: OpenCV(4.6.0) :-1: error: (-5:Bad argument) in function 'resize'
> Overload resolution failed:
>  - src data type = 18 is not supported
>  - Expected Ptr<cv::UMat> for argument 'src'

The server looks like this:

if client_socket:while True:packet = client_socket.recv(4 * 1024)frame = np.array(packet)small_frame = cv2.resize(frame, (0, 0), fx=0.25, fy=0.25)rgb_small_frame = small_frame[:, :, ::-1]

And here's the client:

while True:vid = cv2.VideoCapture(0)while vid.isOpened():time.sleep(0.5)img, frame = vid.read()frame = imutils.resize(frame, 4 * 1024)a = pickle.dumps(frame)message = struct.pack("Q", len(a)) + atry:client_socket.sendall(message)except Exception as e:print(e)raise Exception(e)

Anyone any idea?

As it's a data stream of bytes, I tried to include for instance the sleep function to allow for more processing. Also tried to isolate the client's picture but also got errors.

There are several issues with your code. Regarding your question: You are passing a byte string to resize:

import cv2
import numpy as npcv2.resize(np.array(b"Hello"), (0, 0), fx=0.25, fy=0.25)

Output:

cv2.error: OpenCV(4.5.4) :-1: error: (-5:Bad argument) in function 'resize'
> Overload resolution failed:
>  - src data type = 18 is not supported
>  - Expected Ptr<cv::UMat> for argument 'src'

Please consider:

• don't use pickle for this kind of task, but compress the data to png or similar before sending it
• pass the data length before sending the data and use it on server side to collect the complete data before uncompressing it