HI I'm very new in OpenCV. My previous experience of vision is using Euresys eVision library. Currently I can detect the rectangle edge using OpenCV Canny and HoughLinesP function if the rectangle object is very clear (refer attached 
).
However, I have no idea to detect the rectangle edge if the image full with noise (refer attached 
and 
).
I can easily detect the noise's rectangle edge using eVision library as show attached file (refer attached 
).
Can anyone help me to find what OpenCV methodology should I use to detect the noise's rectangle edge?
Appreciated and Thanks!