Expected Ptr<cv::UMat> for argument 'src'

Question

I have to convert a video to gray format first, then to hsv but I get this error :

Traceback (most recent call last):
  File "c:/Users/eycan/Desktop/serittakip.py", line 8, in <module>
    im = cv2.cvtColor(vid, cv2.COLOR_BGR2GRAY) # grayscale kopya
TypeError: Expected Ptr<cv::UMat> for argument 'src'

My code:

import cv2
import numpy as np

vid = cv2.VideoCapture("C:\\Users\\eycan\\Desktop\\serit\\yol.mp4")

while 1:    #frame cektıgımız ıcın whıle dongusune soktuk resım olsaydı boyle olmazdı
    _,frame = vid.read()
    im = cv2.cvtColor(vid, cv2.COLOR_BGR2GRAY) # grayscale kopya
    vid = cv2.cvtColor(frame,cv2.COLOR_BGR2HSV) #bgr dan hsv ye donusturduk

    lower_white = np.array([0, 0, 212])
    upper_white = np.array([131, 255, 255])

    mask = cv2.inRange(vid,lower_white,upper_white)
    cv2.imshow("Frame",frame)
    cv2.imshow("MASK",mask)

Pls help :/

Answer 1

• The first problem is you need to convert frame to the gray-scale object.

  • im = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)
    

• The second problem is when you convert from BGR2HSV please use different variable, other than vid, since vid is reading the next video frame.

  • im_hsv = cv2.cvtColor(frame,cv2.COLOR_BGR2HSV)
    

• Also, please do change the rest of the vid variable with the im_hsv

  • mask = cv2.inRange(im_hsv,lower_white,upper_white)
    

Code:

---

import cv2
import numpy as np

vid = cv2.VideoCapture("C:\\Users\\eycan\\Desktop\\serit\\yol.mp4")

while 1:    #frame cektıgımız ıcın whıle dongusune soktuk resım olsaydı boyle olmazdı
    _,frame = vid.read()
    im = cv2.cvtColor(frane, cv2.COLOR_BGR2GRAY) # grayscale kopya
    im_hsv = cv2.cvtColor(frame,cv2.COLOR_BGR2HSV) #bgr dan hsv ye donusturduk

    lower_white = np.array([0, 0, 212])
    upper_white = np.array([131, 255, 255])

    mask = cv2.inRange(im_hsv,lower_white,upper_white)
    cv2.imshow("Frame",frame)
    cv2.imshow("MASK",mask)