We closed this forum 18 June 2010. It has served us well since 2005 as the ALPHA forum did before it from 2002 to 2005. New discussions are ongoing at the new URL http://forum.processing.org. You'll need to sign up and get a new user account. We're sorry about that inconvenience, but we think it's better in the long run. The content on this forum will remain online.
Index › Processing Development › Libraries,  Tool Development › BlobDetection library
‹ Previous Topic | Next Topic ›
Pages: 1 2 
BlobDetection library (Read 7831 times)
Quasimondo
Re: BlobDetection library
Reply #15 - Jan 16th, 2006, 1:21am  
Quote:
I'm not sure I get it. This library is doing blog tracking. no ? I mean with it I'm able to track a blob (in a real-time video stream), and therefore to know its coordonates, size.
What do you mean by blog tracking ? Tell me Wink


Blob tracking means that the tracker will keep a reference to each blob over time so you could follow an objects' position automatically. Currently you can only make a guess that if blob 1 was at position x/y in frame 1 and you have blob 2 at position x+2/y-4 at frame 2 that both are probably the same object. In a way it is like Alzheimer's desease - you get know many new people every day.
Back to top
 
Mario Klingemann | Quasimondo | Incubator | côdeazur
WWW  
smallfly
Re: BlobDetection library
Reply #16 - Jan 16th, 2006, 2:30am  
ok, I understand.

but by using this library, for blob detection, with some on my own code I may able to do blob tracking. I can myself "record" information in order to follow blob through time.
Back to top
 
WWW  
v3ga
Re: BlobDetection library
Reply #17 - Jan 17th, 2006, 10:09am  
Hi minga,

1. it's possible to filter blobs. You have to use the method 'activeCustomFilter(Object parent)' on your blobDetection instance, 'parent' being the applet for example. Inside this parent object, you have to implement a method whose definition  is 'boolean newBlobDetectedEvent (Blob b)'. Each time a blob is detected, this function will be called. If you want to keep the blob you return true, otherwise false.
2. Smiley It's in project to add blob tracking in this library.
3. The computed blobs in the image are ok. 'setPosDiscrimination()' is a method mainly targeted at polygon rasterization for a blob (it will draw the inside of the white blob in your case).

Cheers,
Julien.
Back to top
 
site | blog&&
WWW  
smallfly
Re: BlobDetection library
Reply #18 - Jan 17th, 2006, 4:30pm  
hi Julien,

1. Thanks for repeating that. It is clearly mentioned in your documentation, but I didn't see it (I don't know why).

2. great ! Can not wait.

3. I not sure I understand. Does that mean that a specific function is fired everytime a white blob (in my case) is detected. I mean where does the "polygon rasterization" happens ? ... this brings me to my next question ;-).

4. Could you give a little bite more explanation about "Triangles". What are they ?

++++
void computeTriangles()
A call to this function will tell the BlobDetection instance to store polygon informations of each detected blob. By default, polygons are not computed.
+++

Thanks,

Hugues.
Back to top
 
WWW  
v3ga
Re: BlobDetection library
Reply #19 - Jan 20th, 2006, 10:27am  
Here are two pictures :
http://www.v3ga.net/processing/BlobDetection/Library/BlobTriangles_Negative.jpg
http://www.v3ga.net/processing/BlobDetection/Library/BlobTriangles_Positive.jpg
It shows blob triangles, which are only computed if you call the function comptuteTriangles(). There on the pictures you can see the difference between true and false passed to setDiscrimination().
I am going to add those pictures in the documentation, it clearly lacks of imagery to describe functions.
Thanks for feedback anyway.
Cheers
Back to top
 
site | blog&&
WWW  
smallfly
Re: BlobDetection library
Reply #20 - Jan 22nd, 2006, 4:48am  
you're welcome, and once again thanks for your explanations !
Back to top
 
WWW  
st33d
Re: BlobDetection library
Reply #21 - Apr 10th, 2006, 6:03pm  
I'm thinking of developing my Architectris project to include the blob detection library. We were going to originally but I felt we were short of time and needed something that's guaranteed to track player position.

Seeing as player position is not a problem (greatest white = player) I'm thinking of getting the player to say just play with the "T" shaped blocks. The blob detection library would come in to detect a bit of crazy semaphore from the player as to what orientation the block is to land in.

This is moving on from Blob Detection to Blob Recognition. I'd be happy to do a bit more v3ga crediting as the last piece got me a damned good grade.

Just wondering if this would at all work. Has anyone tried using the library for Blob Recognition yet
Back to top
 
WWW  
Pages: 1 2 
‹ Previous Topic | Next Topic ›