The code shows correct image, but show error message after image 'frame' playback. so I couldn't get 'res' image
It just shows me 'No Object Files' error message.
Which part should I fix to make it work?
import cv2
import numpy as np
cap = cv2.VideoCapture('ObjectTrack.mp4')
while cap.isOpened():
ret, frame = cap.read()
if not ret:
print("No Object Files")
break
hsv = cv2.cvtColor(frame, cv2.COLOR_BGR2HSV)
lower_orange = np.array([100,200,200])
upper_orange = np.array([140,255,255])
mask_orange = cv2.inRange(hsv, lower_orange, upper_orange)
res = cv2.bitwise_and(frame,frame,mask = mask_orange)
cv2.imshow('frame',frame)
cv2.imshow('res',res)
if cv2.waitKey(50) & 0xFF == ord('q'):
break
cap.release()
cv2.destroyAllWindows()
The reason behind your error is that the frame is None(Null). and your code enters into this if
if not ret:
print("No Object Files")
break
and then gets out of the while loop ( while cap.isOpened(): ... ).
Just change the indentation and also the if condition
like this:
while cap.isOpened():
ret, frame = cap.read()
if ret: # if frame is not None:
hsv = cv2.cvtColor(frame, cv2.COLOR_BGR2HSV)
lower_orange = np.array([100, 200, 200])
upper_orange = np.array([140, 255, 255])
mask_orange = cv2.inRange(hsv, lower_orange, upper_orange)
res = cv2.bitwise_and(frame, frame, mask=mask_orange)
cv2.imshow('frame', frame)
cv2.imshow('res', res)
if cv2.waitKey(50) & 0xFF == ord('q'):
break
cap.release()
cv2.destroyAllWindows()
The reason is further discussed here.
Related
I have a face detection program.
I tried to run the code but it's not working.
import cv2
import numpy as np
recognizer = cv2.face.LBPHFaceRecognizer_create()
recognizer.read("trainer/trainer.yml")
cascadePath = "haarcascade_frontalface_default.xml"
faceCascade = cv2.CascadeClassifier(cascadePath);
cam = cv2.VideoCapture(0)
fontFace = cv2.FONT_HERSHEY_SIMPLEX
fontScale = 1
fontColor = (255, 255, 255)
while True:
ret, im =cam.read()
gray=cv2.cvtColor(im,cv2.COLOR_BGR2GRAY)
faces=faceCascade.detectMultiScale(gray, 1.2,5)
for(x,y,w,h) in faces:
cv2.rectangle(im,(x,y),(x+w,y+h),(225,0,0),2)
Id, conf = recognizer.predict(gray[y:y+h,x:x+w])
if(conf<50):
if(Id==1):
Id="chandra"
elif(Id==2):
Id="vamsi"
else:
Id="Unknown"
cv2.putText(im,str(Id), (x,y+h),fontFace, 255)
cv2.imshow('im',im)
if (cv2.waitKey(10) == ord('q')):
break
cam.release()
cv2.destroyAllWindows()
I got this error:
(-215:Assertion failed) !empty() in function 'cv::CascadeClassifier::detectMultiScale'
I'm using opencv2 and python 3.7
Maybe this will help:
try:
ret, im =cam.read()
except:
continue
Please, use this code below to check if you have any images coming from your camera:
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',gray)
if cv2.waitKey(1) & 0xFF == ord('q'):
break
# When everything done, release the capture
cap.release()
cv2.destroyAllWindows()
I have a video that I built using OpenCV VideoWriter.
I want to change a specific frame with a different one.
Is there a way to do it without rebuilding the entire video?
I am changing the third frame by making all pixels to zeros.
import numpy as np
import cv2
cap = cv2.VideoCapture(0)
fourcc = cv2.VideoWriter_fourcc(*'XVID')
out = cv2.VideoWriter('output.avi',fourcc, 20.0, (640,480))
frame_number = -1
while(True):
frame_number += 1
ret, frame = cap.read()
if frame_number == 3: # if frame is the third frame than replace it with blank drame
change_frame_with = np.zeros_like(frame)
frame = change_frame_with
out.write(frame)
gray = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)
cv2.imshow('frame',gray)
if cv2.waitKey(1) & 0xFF == ord('q'):
break
cap.release()
out.release()
cv2.destroyAllWindows()
If you do not want to go through all the frames again:
import numpy as np
import cv2
cap = cv2.VideoCapture(0)
fourcc = cv2.VideoWriter_fourcc(*'XVID')
out = cv2.VideoWriter('output.avi',fourcc, 20.0, (640,480))
frame_number = -1
while(True):
frame_number += 1
ret, frame = cap.read()
if frame_number == 3: # if frame is the third frame than replace it with blank drame
change_frame_with = np.zeros_like(frame)
frame = change_frame_with
out.write(frame)
break # add a break here
else:
out.write(frame)
gray = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)
cv2.imshow('frame',gray)
if cv2.waitKey(1) & 0xFF == ord('q'):
break
cap.release()
out.release()
cv2.destroyAllWindows()
But the above solution will not write all the other frames after 3 to the whole new video
This might help you :)
import cv2 as cv
vid = cv.VideoCapture('input.mp4')
total_frames = last_frame_number = vid.get(cv.CAP_PROP_FRAME_COUNT)
fourcc = cv.VideoWriter_fourcc(*'avc1')
writer = cv.VideoWriter("output.mp4", apiPreference=0,fourcc=fourcc,fps=video_fps[0], frameSize=(width, height))
frame_number = -1
while(True):
frame_number += 1
vid.set(1,frame_number)
ret, frame = vid.read()
if not ret or frame_number >= last_frame_number: break
# check these two lines first
if frame_number == changeable_frame_number :
frame = new_img_to_be_inserted
writer.write(frame)
# frame = np.asarray(frame)
gray = cv.cvtColor(frame, cv.IMREAD_COLOR)
# cv.imshow('frame',gray)
if cv.waitKey(1) & 0xFF == ord('q'):
break
vid.release()
writer.release()
cv.destroyAllWindows()
Is there a way to increase the webcam resolution of my webcam in OpenCV Python. The default value is 640x480 but, I want it to be 1365x730. Here's my code:
import cv2
cap = cv2.VideoCapture(0)
while(1):
_, frame = cap.read()
cv2.imshow('frame', frame)
key = cv2.waitKey(1)
if key == 27:
break
cap.release()
cv2.destroyAllWindows()
import cv2
cap = cv2.VideoCapture(0)
cam.set(cv2.CAP_PROP_FRAME_WIDTH, 1280)
cam.set(cv2.CAP_PROP_FRAME_HEIGHT, 720)
while(1):
_, frame = cap.read()
cv2.imshow('frame', frame)
key = cv2.waitKey(1)
if key == 27:
break
cap.release()
cv2.destroyAllWindows()
I have videostreams and I'd like to convert them to foreground detected videos on which everything is white that moving and all others are black.
When I run this below script nothing happens, python ide just waits. Should I wait, does the video render or do i make something wrong?
Thanks
import cv2
import numpy
cap = cv2.VideoCapture('2018_02_28_12_07_42.h264')
fgbg = cv2.createBackgroundSubtractorMOG2()
fourcc = cv2.VideoWriter_fourcc(*'XVID')
out = cv2.VideoWriter('output.avi',fourcc, 20.0, (640,480))
#while(cap.isOpened()):
while True:
ret, frame = cap.read()
#if ret == True:
fgmask = fgbg.apply(frame)
out.write(frame)
cv2.imshow('original', frame)
cv2.imshow('fg', fgmask)
k = cv2.waitKey(30) & 0xff
if k == 27:
break
cap.release()
out.release()
cv2.destroyWindows()
Here is my code:
import cv2
import numpy as np
cap = cv2.VideoCapture(1)
fourcc = cv2.VideoWriter_fourcc('M','J','P','G')
framesize = (640,480)
out = cv2.VideoWriter('dump.avi',fourcc,60.0,framesize)
font = cv2.FONT_HERSHEY_SIMPLEX
while True:
ret, frame = cap.read()
gray = cv2.cvtColor(frame,cv2.COLOR_BGR2GRAY)
cv2.imshow('frame',frame)
cv2.rectangle(gray, (0,0),(640,480),(255,255,255),3)
cv2.putText(gray, "gray", (0,130),font, 5,(255,255,255),2, cv2.LINE_AA)
cv2.imshow('fr',gray)
Here I am trying to color a specific square area on the live image feed
#gray[100:105,110:115] = [255,255,255]
io = gray[37:111,107:194]
Here I am cloning an are into another
gray[200:200,270:283] = io
out.write(frame)
if cv2.waitKey(1) & 0xFF == ord('q'):
break
cap.release()
out.release()
cv2.destroyAllWindows()
How can I color a specific area? As my attempt is not working.