While running a simple opencv video capture script, i am getting False as the result. I suspect it is due to some security setting in Windows 10 which is not allowing camera access. I checked Privacy > Camera settings, but there was no option to allow a script to access the camera. I can see that the camera is not turned on when running the following opencv based test script.
import cv2
cap = cv2.VideoCapture(0)
while(True):
ret, frame = cap.read()
print(ret)
The Key to the answer is "Give time for Microsoft Windows to initalize WebCAM"
import time
capWebcam = cv2.VideoCapture(0)
time.sleep(1.000) # Make sure, you need to give time
# for MS Windows to initialize Camera
It's called "Allow access to classic application" or "Desktop applications" something like this in the bottom of the setting page, under Windows Store type applications.
This gain camera access to all EXE and DLL standalone applications.
One setting for all of them.
More info on exceptions here https://support.microsoft.com/en-us/help/4468234/windows-10-desktop-apps-and-privacy
Works for me in
'cv2.__version__ 4.2.0'
just installed latest opencv and python8 on latest windows10.
As suggested in previous helpful answers, after checking windows camera security setting, adding time delay, and running windows camera app, the program works fine.
Related
I am very new in programming with python :)
My Setup:
Windows 11 Pro
Python 3.7
OpenCV 4.7
Webcam: HD Pro Webcam C920 from logitech
I want to access the camera image in Python. Everything works with my integrated camera.
When I want to access the USB camera, nothing works. I do not get video from my USB webcam.
I try the following code to see, if there is a camera.
import cv2
cap = cv2.VideoCapture(0)
print(cap.isOpened())
It works with my integrated Webcam. I get a True
With cap = cv2.VideoCapture(2) i get False
But if i try this with cap = cv2.VideoCapture(1) i get nothing back and there is no error. The program just keeps running. My conclusion: Somehow the USB camera has to work. Otherwise I would also expect a False for cap = VideoCapture(1).
I have already found and tried many things on the Internet. Unfortunately, nothing has helped.
I have also tried pygame, but that does not seem to run under windows.
How do I get video from my USB camera?
Thanks for your help :)
I'm trying to edit my raspberry program files from network via SSH. For trial and error, I had to look at how the camera is going (seeing video lives, editing the picture quality, maybe adding image recognition in the future). The program can't run from the SSH, at least the part that requires "camera view" to open usually in Linux desktop.
Is there any way to do this correctly? I know Raspberry Pi camera library ran on SystemX, as so the GUI library Tkinter, maybe there's a way to cross this somehow to .NET windows GUI?
edit 1: I use Raspbian OS 32 bit for the OS. I use picamera library. If it helps, there's an error says "PiCameraMMALError...:failed to create MMAL component..:out of memory." I tried connecting to SSH via Windows Powershell and Linux subsystem, both gave me same errors.
edit 2: adding error image, might be useful.
I wonder if there's some mechanism which requires Pi to be connected to monitor to display the camera directly? Or maybe data bandwidth problem? Or just SystemX incompability on ssh hosts?
edit[3]: Adding code snippets to make error checking easier. The code is mostly still just activating camera functions
import tkinter as tk
from picamera import PiCamera
from time import sleep
#camera initiation
camera = PiCamera()
camera.rotation = 180
camera.resolution = (1080, 1080)
#camera start
def cameraStart():
camera.start_preview()
camera.preview_fullscreen = False
camera.preview_window = (0, 0, 650, 480)
#camera stop
def cameraStop():
camera.stop_preview()
#main function:
def main():
while True:
cameraStart()
print("Menu\n")
print(1. Turn off camera")
choice = input("Enter the menu:")
if choice == 1:
cameraStop()
exit()
if __name__ == "__main__":
main()
edit 4: The camera now can works fine without monitor, looks like I misplaced the port before. Thanks to #marksetchell. Now the only problem is to output the camera to windows that ran the ssh. Can it sends the output through my Windows laptop?
So the code works but when the screen pops up it's all black. Can't see any images. I thought my code wasn't picking up the camera but when i ran the external application for the camera (while the code was still running) it said the camera is being used somewhere else (assuming its PyCharm because when I stop the code it works on the external application).
I also tried running the cameras external application prior to running the code but when i do that the code gives me errors. I also tried running the code without the camera plugged in but gives me an error. So I'm assuming it picks up the camera but cant give me an output.
import cv2
print("done")
cap = cv2.VideoCapture(0)
if not(cap.isOpened()):
print("cant open")
cap.set(cv2.CAP_PROP_FRAME_WIDTH, 640)
cap.set(cv2.CAP_PROP_FRAME_HEIGHT, 480)
while(True):
ret,frame=cap.read()
cv2.imshow('preview',frame)
if cv2.waitKey(1)& 0xFF==ord('d'):
break
cap.release()
cv2.destroyAllWindows()
So, it is possible that there is an error in your code, but I think, it's more likely that PyCharm has not got the permission to use your Camera. Try to open cmd(look in the search bar, it's preinstalled) and open it as Administrator. I'm sorry that I can't test it, but I don't have a webcam in my computer.
I'm working on project about vehicles detection and counting, and i'm trying to use trained HAAR cascade provided by opencv using anaconda3, but cv2.VideoCapture(0).isOpened() return False, means that it couldnt open the frames correctly,what should i do ? thank you.
I've already tried to change the parameter 0 to -1 as recommended on the net but it didn't work :/
import cv2
import numpy as np
cap = cv2.VideoCapture(0)
cap.isOpened()
#This one returns False !
Maybe it's the problem with the driver.
You could test if your camera works well in other applications.
It occured to me once on my Ubuntu16.
For Linux, you could use cheese or command line:
ls /dev/video*
to see if your camera is mounted.
For Windows, just open you camera application. But I think the camera driver could barely fail on Windows
I'm trying to learn SimpleCV using Python 2.7 in IDLE.
Once the camera form SimpleCV is initialized the camera become unavailable to other programs like native webcam application or skype etc.
from SimpleCV import *
camera = Camera()
After restarting the pc or logoff and logon the webcam becomes to those applications. It seems that even closing out from python IDLE, it doesn't close the camera stream. Is there any way to stop the camera stream of simplecv?
I couldn't replicate your issue, but if the webcam is still running even after your program terminates/you close IDLE, you can end the camera by going into task manager and killing all running Python processes.
After some experimenting, I found that if you want to accomplish the same thing directly inside the code, you could try simply deleting the reference altogether:
>>> import SimpleCV as scv
>>> cam = scv.Camera()
>>> del cam
Calling del cam caused the webcam indicator light on my laptop to turn off. Granted, this appears to be an undocumented (??) solution, so I'm not sure how robust it is. I would probably try testing this on several different laptops/webcams first, to make sure it works reliably and consistently.