Computer vision, C++ OR Java

Question

I'm a complete newbie in the computer vision world and recently I implemented some examples using OpenCV with Java. I'm impressed with the potential this area has and wish to continue learning more.

I learned that OpenCV is written in C++ and while Java has a wrapper (JavaCV) I understood that the applications in Java are slower than in C++ and most enterprise application are written in C++.

My question is this: I have few years of experience in Java and I feel very comfortable to write any application with it; would it be smart to move to C++ to learn CV or should I stick with Java and use its wrapper.

Answer 1

Computer vision is a demanding area - and while it is true that you'd best stay with what you know, and move to opencv only if performance is needed, another truth is that you'll need to go deep into mathematics, pointers and algorithms to learn and build a good computer vision app. And to do that in Java can be more cumbersome than learning c++.

So, if all you want to do is to apply a filter over an image for some school project - go for Java. But if you want to stay more with OpenCV, to learn vision algorithms or to write your own, my strong suggestion is to learn C++ - isn't that scary!

A reason to write native code is flexibility - you'll want to do all kind of tricks that are difficult or performance-killers in Java.

Shortly speaking, learning C++ is much simpler than computer vision. And OpenCV is not just a library you want to call to do some processing out there. It's bleeding edge technology - you'll want to understand it, to hack into it, to build over it, to go through the code, much more than call someJNIfunc();

And if you do so, please be aware that OpenCV offers two interfaces - one for C and one for C++. And while they offer the same functionality, the C++ one is much like Java - with automatic memory management and more sweeties. You can refer to this post to see the differences