Java image processing - accessing pixel data

[Patrickwhite]

It's worth mentioning that we've found that calling certain NI C/C++ functions from Java is very slow. I find it surprising that it hasn't yet been mentioned that the image classes, namely BinaryImage has a very useful set of methods beyond finding ellipses - the particle report methods. Each "blob" in a binary image is considered a particle, and the particle report allows you to access important properties of each particle, like its position, size, number of pixels in the particle, etc.

[Greg McKaskle]

The jpeg decoder on the cRIO is part of IMAQ. It is pretty standard consortium code and does not run on the FPGA, but runs on theFreescale processor.

Greg Mckaskle

[JewishDan18]

Originally Posted by Patrickwhite

It's worth mentioning that we've found that calling certain NI C/C++ functions from Java is very slow. I find it surprising that it hasn't yet been mentioned that the image classes, namely BinaryImage has a very useful set of methods beyond finding ellipses - the particle report methods. Each "blob" in a binary image is considered a particle, and the particle report allows you to access important properties of each particle, like its position, size, number of pixels in the particle, etc.

Which functions in particular are you having slow results from? I got slow results from the getOrderedParticleAnalysisReports, but the slowdown was on the java end.

[Patrickwhite]

I tossed together a quick sample that retrieved the image from the camera, did a threshold, a convex hull operation, and got the particles, and sorted them by area. The first three of those were done with the BlockingFunction protoyped methods. The whole operation was clocking in at around 400ms with nothing else running on the robot.

[Greg McKaskle]

What size image was this, and did it include decoding the image?

Greg McKaskle