I have been able to successfully find the contours on an entire image. 

 

However,I am more interested to define an ROI interactively and then find the

contours for it, whilst preserving the other parts of the image without any

contour-finding.

 

This is what I'd like to do:

    * Create the ROI interactively for the input image

    

    * Find contours on that ROI (without cropping the ROI away from the rest of image)

    

    * Other parts (which are not in the ROI) should remain untouched. 

Any suggestions/help/code would be great! Thanks,

P.S: Sorry for these questions, but I would be ever grateful for a gentle and kind reply. I am new to OpenCV and SciKit, hence this question. Many thanks!