The opencv element includes were full of duplicates and uneeded headers.
For example a few elements that stopped using gstcvopencvutils still
included that header file.
If old opencv1-style legacy include directory is available,
this change becomes purely cosmetic (maybe will compile a bit faster).
It becomes an FTBFS fix when opencv1-style include directory is missing
(possibly because opencv package maintainer decided not to pack it).
https://bugzilla.gnome.org/show_bug.cgi?id=747705
Add colour image enhancement element based on Retinex algorithm. Two types
exist, namely basic and multiscale; both are described in this article:
Rahman, Zia-ur, Daniel J. Jobson, and Glenn A. Woodell. "Multi-scale retinex
for color image enhancement." Image Processing, 1996. Proceedings.,
International Conference on. Vol. 3. IEEE, 1996
Visually speaking the result looks a bit funny, but is pretty invariable to
lightning changes, which is good for some applications, like image
segmentation.
https://bugzilla.gnome.org/show_bug.cgi?id=700977
