List of best mirrors for IP address 18.189.141.236, located in an unknown country.
I am very sorry, but no mirror was found. Feel free to download directly:
http://mirrordirector-mb.raspbian.org/raspbian/pool/main/o/opencv/libopencv-imgproc-dev_4.6.0+dfsg-14+rpi1_armhf.deb