Chief Delphi - Vision in Java

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First, a disclaimer: I am not a programmer. I am a mechanical mentor dipping my toe into the programming side to help set some wheels in motion for a vision system.

My team is 100% Java. For a variety of reasons we have decided to program in it exclusively.

There are lots of choices for implementing a vision system. On the roboRIO vs on the driver station vs on a co-processor. If on the DS, it could be in roboRealm, NI's code, or something else. I'm not familiar with the individual requirements or pros/cons for each of these options.

My question: as a pure Java team, what is the path of least resistance for getting a vision system up and running? We've never done one and I want to make sure we get something implemented this season, even if it is very basic.

Thanks.

Re: Vision in Java

If you're just looking for getting vision on your dashboard with a USB camera, I stripped down the SimpleVision template to 3 lines of code that you run when initializing everything:

Code:

CameraServer camera = new CameraServer();

camera.setQuality(50);

camera.startAutomaticCapture("cam0");

When you start up the driver station while connected to a RoboRIO running this code, go to the FRC PC Dashboard. In the bottom left of the "drive" pane, there should be a dropdown menu with the options of no camera, SW camera, HW camera, and IP camera. I believe you set this to SW camera (If that doesn't work, try HW camera. It's one of the two. I honestly cant remember, even though I was using it literally 2 hours ago). This should give you a live camera feed in what was formerly a big empty space of the dashboard. One thing I did notice tonight about that string "cam0"; this does not name the camera, it determines what camera to get the feed from. I believe the first camera you connect is automatically addressed as "cam0". I could be wrong on this, I haven't tested using multiple cameras. I learned this the hard way by replacing "cam0" with "PotatoCam", then not understanding why I couldn't get any feed whatsoever.

Good luck!

Re: Vision in Java

Personally, I love team 341's solution to vision in 2012. They ran it on a dashboard that runs on the driver station. It's written in Java and worked very nicely. In my opinion, 341 was one of the most impressive robots to watch.

Re: Vision in Java

Quote:

Originally Posted by Jared (Post 1427104)

I'd second that statement. 341's system was the inspiration for our vision system last year, which was purely in Java. Instead of writing a SmartDashboard plugin, though, we used the Java bindings for OpenCV and NetworkTables to write a Swing app that ran on the driver station. Here's the code if you're interested: https://github.com/LuNaTeCs-316/LuNaCV

Re: Vision in Java

Thanks, I'll take a look at the Daisy implementation. I have heard that JavaCV is poorly documented, at least relative to OpenCV. Has that been your experience?

Re: Vision in Java

It definitely is not as well documented as it is for c and cpp! I might have a vision solution so if it works I will document it and polish up for other teams to use!

Re: Vision in Java

Quote:

Originally Posted by craigboez (Post 1427187)

Thanks, I'll take a look at the Daisy implementation. I have heard that JavaCV is poorly documented, at least relative to OpenCV. Has that been your experience?

I wouldn't use JavaCV (the old third-party Java wrappers) because they only support OpenCV 2 and there is now an official Java API. It does not have its own documentation but the C++ documentation applies to it as well in most cases.

Re: Vision in Java

Quote:

Originally Posted by lopsided98 (Post 1427273)

This. I've noticed a few changes, specifically that there is no IplImage anymore (Mat is the new storage type of choice) and imread/imwrite is in Imgcodecs.