[Py4j-users] faster way to convert arrays from python to Java

[Peter <dih...@gm...>]

I know this is a known/fundamental issue, but just wanted place my request
for a faster way to convert large arrays between the two.  I'm written a
wrapper around BoofCV, which is a computer vision library in Java, using
Py4J.  For the most part it has been really easy to do and works well.  The
one major problem I have is that loading an image in python then passing it
to Java is glacial.

For example, when tracking objects inside a video sequence it takes 28ms to
process the image, but 95ms to convert it from a numpy format into the
BoofCV format!  Kinda kills any hope of doing something in real-time.  Yes
I know you said not to use this library if you want speed, but it's
actually almost there.

Would it be possible to do some sort of hackery like share a large chunk of
memory between the two and use that to do copies?

- Peter