cv2 Error: (-215:Assertion failed) !_src.empty() in function 'cv::cvtColor'

Question

I'm trying to filter red color in my images but I got an error which is cv2.error: OpenCV(4.5.2) C:\Users\runneradmin\AppData\Local\Temp\pip-req-build-ttbyx0jz\opencv\modules\imgproc\src\color.cpp:182: error: (-215:Assertion failed . I have no idea how can I fix this. Here is my code

import cv2
import numpy as np


path = "C:\\Users\\MERYEM\\OneDrive\\Masaüstü\\scan\\Img_Data\\Chosen\\frame3802.jpg"

image = cv2.imread(path)

hsv = cv2.cvtColor(image, cv2.COLOR_BGR2HSV)
lower_red = np.array([178,179,0])
upper_red = np.array([255,255,255])

mask = cv2.inRange(hsv,lower_red, upper_red)

cv2.imshow('Original Image',image)
cv2.imshow('Detection', hsv)

cv2.waitKey(0)
cv2.destroyAllWindows()

I need you help, thanks in advance. Btw, I am using PyCharm if it matters

Your code works fine for me. Are you sure you are using an RGB image, and not YUV or grayscale? And are you really sure those are legitimate HSV values? — Tim Roberts, Aug 30 '21 at 21:26
The error message says that the image is not read. Make sure you have entered the correct path of the image. There is no other reason for this error message. — Rahul Kedia, Aug 31 '21 at 04:14
@TimRoberts hey. I took this code from a youtube channel and I just edited the path. I'm sure that the path is correct however it does not work. Tim, which editor do you use? Maybe this is an editor issue, idk — Meryem Çiftçi, Sep 01 '21 at 04:04
That's hard to imagine. [255,255,255] is not a valid HSV. Have you taken even the simplest debugging steps to print each and every value after you create it, to narrow things down? — Tim Roberts, Sep 01 '21 at 06:52

score 0 · Answer 1 · answered Aug 31 '21 at 07:42

0

Check the image address again or select another image for test.

Also; HSV range for OpenCV is (0-180, 0-255, 0-255)

import cv2
import sys
import numpy as np


im = cv2.imread(sys.path[0]+'/back.png')

hsv = cv2.cvtColor(im, cv2.COLOR_BGR2HSV)
redL = np.array([180*350/360, 0, 0])
redU = np.array([180*360/360, 255, 255])
mask = cv2.inRange(hsv, redL, redU)


mask = cv2.cvtColor(mask, cv2.COLOR_GRAY2RGB)
cv2.imwrite(sys.path[0]+'/out.png',np.hstack((im, mask)))

Output of image and output mask:

More information about modules and their licenses: OpenCV, NumPy

answered Aug 31 '21 at 07:42

Shamshirsaz.Navid

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Hello @Shamshirsaz.Navid, I tried another image and I got the same error. Also, I tried your code and I got the same error :'(. I'm sure that the path is correct – Meryem Çiftçi Sep 01 '21 at 04:10
that is weird :) can you test it in another machine? – Shamshirsaz.Navid Sep 01 '21 at 09:19
my friend tested it on her computer, however it did not work again. she uses vsc btw – Meryem Çiftçi Sep 01 '21 at 13:36
What error does the code I wrote give you? I tested this code and it works fine :) Did you install the required modules? – Shamshirsaz.Navid Sep 01 '21 at 13:49
1

Hello, I found why it did not work. Because my photos is included in OneDrive, it does not work and gives error. When I download new photo, It works because it is not in OneDrive. Thanks for your answers and interest. Appreciated – Meryem Çiftçi Sep 02 '21 at 19:18

cv2 Error: (-215:Assertion failed) !_src.empty() in function 'cv::cvtColor'

1 Answers1