Hand-Gesture-Recognition- | Hand Gesture Recognition using Deep Learning | Machine Learning library

I know this sounds stupid and I'm propably very late to the party but here's the thing I want to program an gesture recogniction application (in the likes of this Hand detection or this actual finger detection) for the Xbox 360 Kinect. SDK (version 1.8) is found, installed and works, preliminary research is done - I only forgot to look in which language to write the code. The link from the SDK to the documentation would be the first thing to do but is a dead end, unfortunately.
From the provided examples it seems either to be C++ or C# although some old posts also claim Java. My question is: Is there a documentation not tied to the SDK and which pitfall are there in regard to developing in this specific case under C++/C#/Java? A post from 2011 barely covers the beginning.

Addendum: On further looking I was prompted for the Samples site from the developer toolkit - which can be reached, yet all listed and linked examples are dead ends too.

Addendum: For reference I userd this instruction - ultimately proving futile.

Found an version of NiTE here

I'm working with OpenCV on hand detection. But I'm struggling when trying to contours of the threshed image. findContour will always try to find white area as contour.

So basically it works in most cases but sometimes my threshed image looks like this :

_, threshed = cv2.threshold(gray, 127, 255, cv2.THRESH_BINARY|cv2.THRESH_OTSU)

So to make it works I just need to change the threshold type cv2.THRESH_BINARY_INV.

_, threshed = cv2.threshold(gray, 127, 255, cv2.THRESH_BINARY_INV|cv2.THRESH_OTSU)

And it works well.

My question is how can I determine when the threshold need to be reversed ? Does I Need to always found contours on both threshed images, and compare the result (I this case How ?) ? or there is a way to allays knows if contours are not totally missed.

EDIT : There is a way to be 100% sure contour looks like a hand ?

EDIT 2 : So I forgot to mention that I'm trying to detect fingertips and defects using this method so I need defects, which with the first threshed image I can't find them, because it reversed. See blue point on the First contour image.

Thanks.