TypeError: lowerb is not a numpy array, neither a scalar

Question

I needed to run some parts of the code in GPU using cupy instead of numpy. So, I only made comment out for this line # import numpy as np and used this line instead of it import cupy as np

the full code:

import cv2
# import numpy as np
import cupy as np
import time
cap = cv2.VideoCapture(0)
while (1):
    _, img = cap.read()


    if _ is True:
        hsv = cv2.cvtColor(img, cv2.COLOR_BGR2HSV)
    else:
        continue

    # red color
    red_lower = np.array([0, 0, 0], np.uint8)
    red_upper = np.array([180,255,30], np.uint8)
    mask = cv2.inRange(hsv, red_lower, red_upper)
    # #
    kernal = np.ones((15, 15), "uint8")
    # # # # #
    mask = cv2.dilate(mask, kernal , iterations=1)
    mask = cv2.GaussianBlur(mask, (11, 11), cv2.BORDER_DEFAULT)
    (_, contours, hierarchy) = cv2.findContours(mask, cv2.RETR_TREE, cv2.CHAIN_APPROX_SIMPLE)
    for pic, contour in enumerate(contours):
        area = cv2.contourArea(contour)
        if (area > 300):
            x, y, w, h = cv2.boundingRect(contour)
            img = cv2.rectangle(img, (x, y), (x + w, y + h), (0, 0, 0), 2)
            cv2.putText(img, "black Colour", (x, y), cv2.FONT_HERSHEY_SIMPLEX, 0.7, (0, 0, 0))


    cv2.imshow("Color Tracking", img)
    if cv2.waitKey(10) & 0xFF == ord('q'):
        cap.release()
        cv2.destroyAllWindows()
        break

how to fix this error so that use cupy.

Traceback (most recent call last):
  File "/home/redhwan/learn.py", line 18, in <module>
    mask = cv2.inRange(hsv, red_lower, red_upper)
TypeError: lowerb is not a numpy array, neither a scalar

I think we can't use some applications of numpy with cupy.

please, your ideas or any suggestions?

Answer 1

thanks for your question.

Opencv does not work with cupy arrays, you will need to convert back and from cupy when calling Opencv using the cupy.asnumpy and cupy.asarray functions.