[PD] multiblob tracking in Gem while objects keep their IDs

[Max]

Am 27.05.2013 um 02:24 schrieb Jack <jack at rybn.org>:

> Le 27/05/2013 01:26, Max a écrit :
>> Am 27.05.2013 um 01:00 schrieb Jack <jack at rybn.org>:
>>> Le 26/05/2013 20:56, Max a écrit :
>>>> hi list, a student of mine, Jakob Gomoll, did solve how to track multiple blobs while every blob keeps its ID.
>>>> Here is where i scratch my head: It works fine until you render the output of the multiblob tracker to a rectangle.
>>>> I'd like to understand why this is.
>>>> 
>>>> Is it a bug or a feature?
>>>> connect the tracker to the pix_texture (where the red line is) and it will mess up the result:
>>>> 
>>> Hello Max,
>>> This could be interesting for you :
>>> http://www.mail-archive.com/pd-list@iem.at/msg42343.html
>> Thanks Jack,
>> I know – I have posted on this thread too. We solved this problem differently. Because our application was microscopy and we had specimen who were stopping their movement for a while before moving on, the continuity approach wasn't working. Since we based the blob detection on frame differences [pix_movement] rather than background subtraction from a reference frame [pix_background] blobs who were resting for a few frames simply disappeared and got a new ID assigned.
>> Our approach is to set a time-out after we declare a blob dead. If it starts moving in the same region (size is settable too) again before the time-out, we pick up the old ID. So rather than using movement vectors as reference we used proximity. All data is stored in tables.
>> 
>> The patch works beautifully without any externals. Have you tried?
>> 
>> So this problem is already solved - my question was rather a Gem thing: why does is stop working when I want to render the image behind it? Do you know this?
>> 
>> Max
>> 
> Sorry, i didn't see your patch in your previous post.
> If I try to open it, i get :
> arraysize blob_ids
> ... couldn't create
> 
> What is [arraysize] ?

oh, darn - seems it isn't completely vanilla then. it is an external by Juha Vehviläinen
http://puredata.info/downloads/arraysize