I'm trying to show the webcam capture on screen in my raspberry pi. It shows first frame with no problem but next ones are displayed as grey frames.
This works on windows but not on raspberry.
import cv2 as cv
cap = cv.VideoCapture(0)
ret, frame = cap.read()
cv.imshow('frame0',frame)
while True:
ret, frame = cap.read()
cv.imshow('frame',frame)
if cv.waitKey(1) == ord('q'):
break
cap.release()
cv.destroyAllWindows()
First install the Picamera module and then try:
# import the necessary packages
from picamera.array import PiRGBArray
from picamera import PiCamera
import time
import cv2
# initialize the camera and grab a reference to the raw camera capture
camera = PiCamera()
camera.resolution = (640, 480)
camera.framerate = 32
rawCapture = PiRGBArray(camera, size=(640, 480))
# allow the camera to warmup
time.sleep(0.1)
# capture frames from the camera
for frame in camera.capture_continuous(rawCapture, format="bgr", use_video_port=True):
# grab the raw NumPy array representing the image, then initialize the timestamp
# and occupied/unoccupied text
image = frame.array
# show the frame
cv2.imshow("Frame", image)
key = cv2.waitKey(1) & 0xFF
# clear the stream in preparation for the next frame
rawCapture.truncate(0)
# if the `q` key was pressed, break from the loop
if key == ord("q"):
break
Source: https://www.pyimagesearch.com/2015/03/30/accessing-the-raspberry-pi-camera-with-opencv-and-python/
Related
Using OpenCV, I have been extracting the frames from a video and after working on the frames, I have been trying to save them to a new video file. But the new video file is not being saved properly. It gets saved as 0 KB in size and throws the following error when I try to open it.
OpenCV Error
My code is as follows:
import cv2
cap = cv2.VideoCapture("Path to source video")
out = cv2.VideoWriter("Path to save video", cv2.VideoWriter_fourcc(*"VIDX"), 5, (1000, 1200))
print(cap.isOpened())
while True:
# Capture frame-by-frame
ret, frame = cap.read()
# Write the video
out.write(frame)
# Display the resulting frame
cv2.imshow('frame',frame)
if cv2.waitKey(1) & 0xFF == ord('q'):
break
cap.release()
out.release()
cv2.destroyAllWindows()
I tried to follow the solution Can't save a video in opencv but it did not help in my case.
when saving the file, your width and height should match with frame's width and height, so in order to get the width and height of the frame automatically, use
import cv2
cap = cv2.VideoCapture(0)
width = int(cap.get(cv2.CAP_PROP_FRAME_WIDTH)) # to get width of the frame
height = int(cap.get(cv2.CAP_PROP_FRAME_HEIGHT)) # to get height of the frame
out = cv2.VideoWriter("dummy_video.mp4", cv2.VideoWriter_fourcc(*"VIDX"), 5, (width, height))
print(cap.isOpened())
while True:
# Capture frame-by-frame
ret, frame = cap.read()
# Write the video
out.write(frame)
# Display the resulting frame
cv2.imshow('frame',frame)
if cv2.waitKey(1) & 0xFF == ord('q'):
break
cap.release()
out.release()
cv2.destroyAllWindows()
I am beginner in CV. My camera crash every time.
I mean camera light is ON but the there is no camera display
Could someone help me?
Here is the code
import cv2 as cv
import numpy as np
cap=cv.VideoCapture(0)
# read webcam untill the end
while (cap.isOpened()):
# capture frame by frame
ret,frame=cap.read()
if ret == True:
# to display frame
cv.imshow("Frame",frame)
else:
break
cv.waitKey(1)
cap.release()
cv.destroyAllWindows()
i think you put waitKey in wrong place, I hope below code will work !
import cv2 as cv
cap = cv.VideoCapture(0)
# read webcam untill the end
while (cap.isOpened()):
# capture frame by frame
ret, frame = cap.read()
if ret == True:
# to display frame
cv.imshow("Frame", frame)
if cv2.waitKey(1) & 0xFF == ord('q'):
break
else:
break
cap.release()
cv.destroyAllWindows()
#tahir mehmood. I modified your code, and I tested it. Worked well.
import cv2 as cv
import numpy as np
cap=cv.VideoCapture(0)
# read webcam untill the end
while (cap.isOpened()):
# capture frame by frame
ret,frame=cap.read()
if not ret:
break
cv.imshow("Frame",frame)
cv.waitKey(1)
cap.release()
cv.destroyAllWindows()
I'm simply trying to get the image of my webcam in python with OpenCV 4.2.0 (on Spyder - python 3.7 running on windows 10). I just copy-pasted the code of the OpenCV documentation (see below) and most of the time it prints: "Can't receive frame (stream end?). Exiting ..."
So I know the error comes from: ret, frame = cap.read(). But I don't know how to fix this.
Sometimes it prints: "Cannot open camera" and then it exits the Spyder Console and starts a new one
And sometimes it just works great...
Can anyone help?
Here is my code:
import numpy as np
import cv2 as cv
cap = cv.VideoCapture(0)
if not cap.isOpened():
print("Cannot open camera")
exit()
while True:
# Capture frame-by-frame
ret, frame = cap.read()
# if frame is read correctly ret is True
if not ret:
print("Can't receive frame (stream end?). Exiting ...")
break
# Our operations on the frame come here
gray = cv.cvtColor(frame, cv.COLOR_BGR2GRAY)
# Display the resulting frame
cv.imshow('frame', gray)
if cv.waitKey(1) == ord('q'):
break
# When everything done, release the capture
cap.release()
cv.destroyAllWindows()
Added the last line to close the window
I had a similar issue (now for a while). I run Linux, not Windows. I read video feeds from multiple IP cameras, not just one webcam. But I believe the solution would be the same. In my opinion, it looks as if the feed, or OpenCv stops supplying frames. So I simply recreate cap, test ret, and move on. This will create a endless loop, it will never stop. In my scenario this correct. I want to real all frames, all the time.
It will look something like:
import numpy as np
import cv2 as cv
cap = cv.VideoCapture('rtsp://1.2.3.4:554//Streaming/Channels/1')
if not cap.isOpened():
print("Cannot open camera")
exit()
while True:
# Capture frame-by-frame
ret, frame = cap.read()
# if frame is read correctly ret is True
while ret == False:
print("Can't receive frame. Retrying ...")
cap.release()
cap = cv.VideoCapture('rtsp://1.2.3.4:554//Streaming/Channels/1')
ret, frame = cap.read()
# Our operations on the frame come here
gray = cv.cvtColor(frame, cv.COLOR_BGR2GRAY)
print('frame')
# Display the resulting frame
cv.imshow('frame', gray)
if cv.waitKey(1) == ord('q'):
break
# When everything done, release the capture
cap.release()
cv.destroyAllWindows()
import numpy as np
import cv2 as cv
cap = cv.VideoCapture(0)# In place of zero we gonna use path of the video file.
while cap.isOpened():
# Capture frame-by-frame
ret, frame = cap.read()
# if frame is read correctly ret is True
if ret:
# Our operations on the frame come here
gray = cv.cvtColor(frame, cv.COLOR_BGR2GRAY)
# Display the resulting frame
cv.imshow('frame', gray)
if cv.waitKey(1) == ord('q'):
break
else:
print("camer not streaming")
# When everything done, release the capture
cap.release()
cv.destroyAllWindows()
I'm trying to resize frame image-array in original (480,640,3) to (224,224,3), but I use
CV_CAP_PROP_FRAME_WIDTH, CV_CAP_PROP_FRAME_HEIGHT, only change size of frame that displayed on my screen. Thank you very much!
My code here!
import cv2
import numpy as np
cap = cv2.VideoCapture(0)
while(True):
# Capture frame-by-frame
ret, frame = cap.read()
frame = cv2.flip(frame, 1)
# Display the resulting frame
cv2.imshow('frame',frame)
print(frame.shape)
if cv2.waitKey(1) & 0xFF == ord('q'):
break
# When everything done, release the capture
cap.release()
cv2.destroyAllWindows()
you can add following code in your while loop,
frame = cv2.resize(frame, (224, 224))
print(frame.shape)
import numpy as np
import cv2
#holder for the camera object
cap = cv2.VideoCapture(0)
while(True):
# Capture frame-by-frame
ret, frame = cap.read()
# Our operations on the frame come here (color)
color = cv2.cvtColor(frame, 1)
# Display the frame
cv2.imshow('LiveCam',color)
if cv2.waitKey(1) & 0xFF == ord('q'):
break
'''When everything done, release the capture'''
cap.release()
cv2.destroyAllWindows()
This code will display my own live frames on my own screen.
I want to send my live frames to another computer,and to receive the other's computer own live in order to display it.
Can I get some help please?