Assertion failed in imread() function

Question

I'm trying to do a simple template matching with openCV-python, but right in the beginning getting an error. I've run the following code:

import cv2 as cv
import numpy as np


haystackImg = cv.imread('fullImage.png', cv.IMREAD_UNCHANGED)
needleImg = cv.imread('diamond.png', cv.IMREAD_UNCHANGED)

result = cv.matchTemplate(haystackImg,needleImg, cv.TM_CCOEFF_NORMED)

cv.imshow('result', result)
cv.waitKey() ```

...and I got this error:

[ WARN:0@0.186] global D:\a\opencv-python\opencv-python\opencv\modules\imgcodecs\src\loadsave.cpp (239) cv::findDecoder imread_('fullImage.png'): can't open/read file: check file path/integrity
[ WARN:0@0.195] global D:\a\opencv-python\opencv-python\opencv\modules\imgcodecs\src\loadsave.cpp (239) cv::findDecoder imread_('diamond.png'): can't open/read 
file: check file path/integrity                                                                                                                                 ython39/python.exe "c:/U
Traceback (most recent call last):
  File "[myFilePath]\starting.py", line 8, in <modd file: check file path/ule>
    result = cv.matchTemplate(haystackImg,needleImg, cv.TM_CCOEFF_NORMED)
cv2.error: OpenCV(4.5.5) D:\a\opencv-python\opencv-python\opencv\modules\imgproc\src\templmatch.cpp:588: error: (-215:Assertion failed) corr.rows <= img.rows + 
templ.rows - 1 && corr.cols <= img.cols + templ.cols - 1 in function 'cv::crossCorr'

The confusing part of it, that I didn't even have a D: drive, and the module is searching for something on that. I reinstalled it, but it didn't help.

Answer 1

The problem was, that my source path contained non ASCII characters such as á and é... Created a new location without any non ASCII characters and white-spaces, and it works fine now.