Re: [Java-player-users] problems using blobfinder

[Radu B. R. <ru...@cs...>]

Hello Alberto,

Sorry for replying so late (hmm, looks like I'm the only one actually 
doing that on this mailing list :)). I just uploaded a basic Blobfinder 
example to the Javaclient examples web page. Maybe that will help.

Please modify your source code according to the following guidelines, 
and try again:
- before the while (true), add a line like "robot.runThreaded (-1, -1);"
- remove the "bfi.readData();" from the main while loop;
- add a delay such as "try { Thread.sleep (100); } catch (Exception e) { 
}" in the main while loop.

I don't know about Gazebo, but I will have a look.

Best regards,
Radu.

-- 
| Radu Bogdan Rusu | http://rbrusu.com/
| http://www9.cs.tum.edu/people/rusu/
| Intelligent Autonomous Systems
| Technische Universitaet Muenchen


Alberto Amengual wrote:

> Hello everybody,
>
> This is the first time I am using javaclient and also Player/Gazebo. I 
> am trying to detect a blue cylinder using blobfinder, but it's not 
> working. I don't know if my problem is the way I am using the java 
> client, or might be related with the color file in cmvision, or other 
> things.
>
> In the world file, I have a Pioneer2AT robot with a SonyVID30 camera, 
> and a couple of SimpleSolids, one of which is a cylinder, with 
> <color>0.0 0.0 1</color> (the others are not blue).
>
> Then, in the player file, I have
>
> driver
> (
>     name "gz_camera"
>     provides ["camera:0"]
>     gz_id "camera1"
> )
>
> driver
> (
>     name "cmvision"
>     provides ["blobfinder:0"]
>     requires ["camera:0"]
>     colorfile ["colorfile"]
> )
>
> The client code I am trying is:
>
> PlayerClient robot = new PlayerClient("localhost", 6665);
> BlobfinderInterface bfi = new robot.requestInterfaceBlobFinder(0,'r');
> short numBlobs = 0;
> bfi.setTrackingColor(0,0,0,0,250,255);
> while (true) {
>    bfi.readData();
>    numBlobs = bfi.getBlobCount();
>    System.out.println("num blobs="+numBlobs);
> }
>
> I get different values back for num blobs (0, 10, 88, 4608, ...), and 
> also sometimes in the client I get an "outofBounds" exception,
> "Error when reading payload: java.lang.ArrayIndexOutOfBoundsException: 
> 256", I guess that the number of "detected" blobs might be too big.
>
> Anybody can help???
>
>
>
> Many thanks,
>
> Alberto Amengual