I´m working with C12741-03 Hamamatsu camera conected by USB, i want to control it with OpenCV, with this code i can control the webcam of my computer and a normal USB camera, but hamamatsu camera, what need a API to work and what i have instaled, doesn´t work. I like to know if there are any way to indicate VideoCapture() function the path of the camera or something like that for start the comunication with it. Im working in windows and if you know another library to work with the camera tell me too. Thanks.
import cv2
import numpy as np
cap = cv2.VideoCapture(0)
if(cap.isOpened()==False):
print("ERROR AL ABRIR LA CAMARA")
while(cap.isOpened()):
ret, frame = cap.read()
if ret == True:
cv2.imshow("Frame", frame)
if cv2.waitKey(25) & 0xFF == ord("q"):
break
cap.release()
cv2.destroyAllWindows()
Try changing cap = cv2.VideoCapture(0) to cap = cv2.VideoCapture(1).
Related
This is my first time using OpenCV and I'm having some difficulties. I just made a simple program to see if it was imported correctly:
import cv2
import numpy as np
print("hi")
cap = cv2.VideoCapture(0)
print(cap.isOpened())
print("hi")
while True:
ret, frame = cap.read()
cv2.imshow('frame', frame)
if cv2.waitKey(1) & 0xFF == ord('q'):
break
cap.release()
cv2.destroyAllWindows()
When I run this file on the MacOS terminal, it works fine and opens up the video window, but when I run this file with IDLE nothing happens. No errors or warnings, the first "hi" prints but nothing else and the program ends. It's like as soon as I try to use cv2 directly after the first "hi", the program just ends. I believe I'm using the same version of python in both my terminal and IDLE, and I've tried uninstalling and reinstalling OpenCV using pip. Did I not install OpenCV correctly to be using with IDLE? Any help is greatly appreciated!
Edit: Not sure if this is causing any problems, but when I first ran it from IDLE, it had a few "Python quit unexpectedly" windows before I tried it in terminal. When I tried it there, it asked for access to my computer's webcam. Since then, the "Python quit unexpectedly" windows haven't showed up when I tried IDLE, so maybe it just needs access to my camera? I don't see an option for that in my Mac settings though, there's no IDLE app option to give access to.
Can you try this.
Snippet:
# -*- coding: utf-8 -*-
import numpy as np
import cv2
cap = cv2.VideoCapture(0)
print(cap.isOpened())
while(cap.isOpened()):
ret, frame = cap.read()
cv2.imshow('frame', frame)
if (cv2.waitKey(1) & 0xFF == ord('q')):
break
cap.release()
cv2.destroyAllWindows()
Or:
snippet:
import cv2
cv2.namedWindow("preview")
vc = cv2.VideoCapture(0)
rval, frame = vc.read()
while True:
if frame is not None:
cv2.imshow("preview", frame)
rval, frame = vc.read()
if cv2.waitKey(1) & 0xFF == ord('q'):
break
I wrote a script for an image processing. I need to take a frame from camera and then make some operations. I can do this but the time when script is initializing the camera is very long. Is there any solution that I will run my script and camera will be working all the time and for example when I will press a button it will save a frame?
This is my code for now:
import cv2
cap = cv2.VideoCapture(1)
cap.set(3, 640)
cap.set(4, 480)
while True:
_, img = cap.read()
cv2.imshow('Output', img)
if cv2.waitKey(1) & 0xFF==ord('s'):
print('DO IMAGE PROCESSING...')
elif cv2.waitKey(1) & 0xFF==ord('q'):
break
cap.release()
cv2.destroyAllWindows()
The problem is that when I am pressing "q" sometimes it doesn't stop. Can you give me an advice which loop or maybe which lib should I use for that?
Thanks!
I would like to lunch a usb-camera at my raspberry pi, but when I try to start python code (opencv), it shows this message and stop a lunch
ASSERT: "false" in file qasciikey.cpp, line 501
Aborted
Can someone please explain me, what error is this?
It doesnt work even with another codes as well... But camera works fine, when I open it in programs like Camorama webcam viewer. I read that this part makes a problem
cv2.waitKey(20)
So it makes in another code (when i uncomment it, it lunch the code but dont show camera output) But in this code, even if I uncomment it, the code themself doesn't work: show upper error message
Here is the code
import numpy as np
import cv2
cap = cv2.VideoCapture(0)
while(True):
# Capture frame-by-frame
ret, frame = cap.read()
# Our operations on the frame come here
gray = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)
# Display the resulting frame
cv2.imshow('frame',frame)
cv2.imshow('gray',gray)
if cv2.waitKey(20) & 0xFF == ord('q'): # HERE
break
# When everything done, release the capture
cap.release()
cv2.destroyAllWindows()
oh are you Japanese yes bro computers are little racist do not press any japanese letter while your code runing. for waitKey you can use esc or number keys:
if cv2.waitKey(20) & 0xFF == ord('0'):
break
This is the code when i execute it:
You can see the frame opens but doesnt show anything
I want to use a usb camera with a raspberry pi 3 model b v1.2 using opencv 3.3 and python 2.7.
I work with opencv in an virtual enviroment.
import numpy as np
import cv2
cap = cv2.VideoCapture(0)
while(True):
ret, frame = cap.read() #Capture frame-by-frame
#Our operations on the frame come here
#gray = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)
#Display resulting frame
cv2.imshow('frame',frame)
cv2.waitKey(10)
#if cv2.waitKey(1) & 0xFF == ord('q'):
# break
#when everything done, release the capture
cap.release()
cv2.destroyAllWindows()
I just have no idea how to get around this error. I already searched the error and i am getting helpless, anyone having an idea?
EDIT: i am currently playing around with the code and i can get frames but most of the time the screen stays grey. I use # to show how the code looks now
Ok, it now opens a window and shows the output of the camera
Because of this code:
import sys
sys.path.append('/home/pi/.virtualenvs/cv/lib/python2.7/site-
packages/usr/local/lib/python2.7/site-packages')
and i also use sudo python program.py in the terminal
But this Error :"NameError: name 'CV_CAP_PROP_FRAME_HEIGHT' is not defined" still persists...
How can i make the cv2.VideoCapture(0) recognize the USB camera of raspberry-pi.
def OnRecord(self, evt):
capture = cv2.VideoCapture(0)
if (not capture.isOpened()):
print "Error"
# video recorder
fourcc = cv2.cv.CV_FOURCC(*'XVID') # cv2.VideoWriter_fourcc() does not exist
video_writer = cv2.VideoWriter.open("output.mp4", fourcc, 20, (640, 480), True)
# record video
while (capture.isOpened()):
ret, frame = capture.read()
if ret==True:
video_writer.write(frame)
cv2.imshow('Video', frame)
else:
break
def OnCancel(self, evt):
capture.release()
video_writer.release()
cv2.destroyAllWindows()
but it only prints Error.
So i guess capture is not opening. What might be the reason?
I tried this code from opencv documentation but doesn't worked out for me.
import numpy as np
import cv2
cap = cv2.VideoCapture(0)
# Define the codec and create VideoWriter object
fourcc = cv2.VideoWriter_fourcc(*'XVID')
out = cv2.VideoWriter('output.avi',fourcc, 20.0, (640,480))
while(cap.isOpened()):
ret, frame = cap.read()
if ret==True:
frame = cv2.flip(frame,0)
# write the flipped frame
out.write(frame)
cv2.imshow('frame',frame)
if cv2.waitKey(1) & 0xFF == ord('q'):
break
else:
break
# Release everything if job is finished
cap.release()
out.release()
cv2.destroyAllWindows()
Any help would be greatly appreciated.
Load the correct video for linux drivers.
sudo modprobe bcm2835-v4l2
In my experience with CV2 replacing a webcam source on linux isn't always easy. How OpenCV works is it automatically draws from the systems default video source, which is known (usually) as video0. Unplug your usb webcam and go into a terminal and typing ls /dev/video*
Remember the number it says. Now plug in your USB webcam and type in ls /dev/video* again and look for any new /video, this is your USB webcam. Now type mv /dev/videoX videoY while X is the number of your USB webcam and Y the original number. This will replace your pi's default camera.
This isn't permanent as you will need to do this every time your pi starts up, an alternative to this is creating a bash file that runs on start up. Create a text file and copy the following into it.
#!/bin/bash
mv /dev/videoX videoY
(replace the X and Y of course)
and place that in /etc/init.d directory of your pi. Don't forget you may need to use
chmod 755 /etc/init.d/FILENAME.sh
to give it permission to run
Go to terminal and type lsusb and check whether the USB camera is recognized or not. If it is recognized then try to give different device ID such as 1 or 2 or 3 rather than 0.
looks Like you might have issue with codec, try using 'MJPG' codec instead of XVID.
For more details have a look here
Make sure that the camera that you are using is UVC compatible, as openCV running on linux based systems (like a raspi) starts to do some silly things when it is working with non UVC cameras.