Python openCV and scikit-image comparison

We are working with many very large images and I decided to invest some time in comparing two popular image processing libraries in Python, openCV and scikit-image. 

Image shape : (26040, 47680, 3)
System   : Windows 7
Machine  : AMD64
Processor : Intel(R) Xeon(R) CPU E5-2643 0 @ 3.30GHz, 3293 MHz, 4 cores
RAM : 128 GB
Python :  2.7.12
openCV : 2.4.13
scikit-image : 0.13.0