opencv @3.4.3: +contrib not configured correctly

[jtressle]

I'm able to compile Opencv 3.4.3 correctly with +contrib. However, the +contrib portion doesn't work.

Both SIFT and SURF work in 3.4.1. However, they do not work in 3.4.3. You can test by running the following code:

cv::Ptr<cv::xfeatures2d::SIFT> sift = cv::xfeatures2d::SIFT::create();

The last working version of Opencv is in commit 01d8762/macports-ports.

Thanks

[jtressle]

Looks like CMAKE for +contrib version needs to be configured with:

    -DOPENCV_ENABLE_NONFREE:BOOL=ON

This flag wasn't enforced on 3.4.1.

[ryandesign (Ryan Carsten Schmidt)]

Has duplicate #61415.

[jmroot (Joshua Root)]

According to the duplicate, this is because the algorithm is patent-encumbered. I don't know if we are even legally able to turn it on.

[mascguy (Christopher Nielsen)]

Optional variant +nonfree will be added via the following pull request:

​https://github.com/macports/macports-ports/pull/9555

[Christopher Nielsen <mascguy@…>]

In ca9ffa681f453399942385f9ef34cf1c124b6ea4/macports-ports (master):

opencv/opencv4: eliminate conflicts, improve consistency, add variants; update gerbil and py-pytorch for opencv4 changes

opencv: eliminate conflict with opencv4; add variants debug, nonfree, tests
opencv4: eliminate conflict with opencv; switch to shared libs; rename variant opencv_contrib to contrib, to match opencv; add variants debug, java, python35..39, qt4, qt5, tbb, tests, vtk
gerbil: update for opencv4 library move
py-pytorch: update for opencv4 library move

Fixes: #61912
Fixes: #61801
Fixes: #60118
Fixes: #58845
Fixes: #57640
Fixes: #51734
Fixes: #48218
Fixes: #32528