Problems with Morphology

[jabarabara]

So, in the past week I've been working on computer vision for this year's competition. I was able to create a binary image by thresholding an image for HSV ranges, but when I try to use morphology dilation I get an error


NIVision.Image img, bin, morph;
NIVision.RawData colorTable;

final NIVision.Range HUE_RANGE = new NIVision.Range(213,255);
final NIVision.Range SAT_RANGE = new NIVision.Range(217,255);
final NIVision.Range VIS_RANGE = new NIVision.Range(102,204);

public void robotInit() {
img = NIVision.imaqCreateImage(NIVision.ImageType.IMAGE_ RGB, 0);
bin = NIVision.imaqCreateImage(NIVision.ImageType.IMAGE_ U8, 0);
morph = NIVision.imaqCreateImage(NIVision.ImageType.IMAGE_ U8, 0);
colorTable = new NIVision.RawData();
}

public void operatorControl() {
NIVision.imaqReadFile(img, "/home/lvuser/capture.jpg");
NIVision.imaqColorThreshold(bin, img, 255, NIVision.ColorMode.HSV, HUE_RANGE, SAT_RANGE, VIS_RANGE);
NIVision.imaqWriteJPEGFile(bin, "/home/lvuser/bin.jpg", 2000, colorTable);
NIVision.imaqMorphology(morph, bin, NIVision.MorphologyMethod.DILATE, new NIVision.StructuringElement(3,3,1));
NIVision.imaqWriteJPEGFile(morph, "/home/lvuser/morph.jpg", 2000, colorTable);
}


I got this error from the code above:


VisionException [com.ni.vision.VisionException: imaqError: -1232673104: Unknown error]
at com.ni.vision.NIVision._imaqMorphology(Native Method)
at com.ni.vision.NIVision.imaqMorphology(NIVision.jav a:24502)
at org.usfirst.frc.team2415.robot.Robot.operatorContr ol(Robot.java:47)
at edu.wpi.first.wpilibj.SampleRobot.startCompetition (SampleRobot.java:159)
at edu.wpi.first.wpilibj.RobotBase.main(RobotBase.jav a:242)


I've already tried searching for the problem to find a solution and couldn't. I don't see what's wrong. Any ideas?

[Ozuru]

Is there any particular reason you're using NIVision instead of OpenCV?

[Ozuru]

I tried OpenCV at first, but I could never get the code to load the library :(.

I highly recommend using OpenCV over NIVision.

Also, to load the library:

static {
System.loadLibrary(Core.NATIVE_LIBRARY_NAME);
}

[jabarabara]

I highly recommend using OpenCV over NIVision.

Also, to load the library:

static {
System.loadLibrary(Core.NATIVE_LIBRARY_NAME);
}

I'll try and see if I it will load then and get back to you.

P.S.: sorry for deleting my earlier message. I was trying to rewrite it as a reply to your post, not just another post. Still new :P

[Ozuru]

I'll try and see if I it will load then and get back to you.

P.S.: sorry for deleting my earlier message. I was trying to rewrite it as a reply to your post, not just another post. Still new :P

No problem. I recommend trying to use OpenCV. If you're new to vision tracking, 341's 2012 vision code is required reading: http://www.chiefdelphi.com/media/papers/2676

[jabarabara]

Okay, so now I've tried your methon and I get:


java.lang.UnsatisfiedLinkError: no opencv_java310 in java.library.path
at java.lang.ClassLoader.loadLibrary(ClassLoader.java :1857)
at java.lang.Runtime.loadLibrary0(Runtime.java:870)
at java.lang.System.loadLibrary(System.java:1119)
at org.usfirst.frc.team2415.robot.Robot.<clinit>(Robot.java:13)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:259)
at edu.wpi.first.wpilibj.RobotBase.main(RobotBase.jav a:204)


with this as code (added the try catch after the first time it failed to get error printed neatly):


import org.opencv.core.Core;
import edu.wpi.first.wpilibj.SampleRobot;

public class Robot extends SampleRobot {

static{
try{
System.loadLibrary(Core.NATIVE_LIBRARY_NAME);
}catch(UnsatisfiedLinkError e){
e.printStackTrace();
}
}

public void robotInit() {}

public void autonomous() {}

public void operatorControl() {}

public void test() {}
}


I tried putting the .so file for opencv in the same directory as the FRCUserProgram on the roboRio, and it still returns this error.

[Ben Wolsieffer]

Since you know exactly where the opencv library is located, you have the option of calling System.load("/path/to/library"). Also, make sure that the file is named "libopencv_java310.so", or System.loadLibrary() won't be able to find it.

[jabarabara]

Okay I figured out the problem.

1) I didn't have all the necessary dependencies in the directory of the opencv_java"version".so

2) Beforehand, I placed the files in a "/usr/local/lib," and it turns out that I don't have the necessary permissions to load the library from there. Moving the library and its dependencies to the directory of FRCUserProgram.jar fixed that.

I now have OpenCV running on the roboRIO, so I can finally continue Vision Processsing. Thanks for all the help everyone!!!!

[Ozuru]

Okay I figured out the problem.

1) I didn't have all the necessary dependencies in the directory of the opencv_java"version".so

2) Beforehand, I placed the files in a "/usr/local/lib," and it turns out that I don't have the necessary permissions to load the library from there. Moving the library and its dependencies to the directory of FRCUserProgram.jar fixed that.

I now have OpenCV running on the roboRIO, so I can finally continue Vision Processsing. Thanks for all the help everyone!!!!

Great progress!

I suggest you do not do vision processing on your roboRIO itself. The processing will cause stuttering on your robot's end. I highly recommend sending the frame to the driver's station and then doing processing there in a stand-alone application.

[euhlmann]

Running vision on the DS laptop will result in huge delay times (obviously). We are running vision on-board in a separate thread and it seems to work fine (main robot loop still runs at 50x/sec)