[PD] pix_multiblob pix_blobtracker

[IOhannes m zmoelnig]

arno liegeon wrote:
> Hello, I use pd-0.39.2-extended-test5 on a ibook G4 with Mac OsX 10.4. I
> try to use "pix_multiblob" object but I don't know how find the valures
> of others blobs than the first one. In reference, patch show a
> "pd_showblob 1" only but I want others blobs.

[pix_multiblob] outputs the data as a matrix as used by iemmatrix.

the format is rather simple, as it is a message:
"matrix <#r> <#c> <a_1_1> <a_1_2> ... <a_1_#c> <a_2_1> ... <a_#r_#c>"

in short:
"matrix 2 3 10 20 30 7 6 5"
denotes a matrix 2x3 matrix:
  10 20 30
   7  6  5

(btw, it is always a good idea to just inspect the actual message you
want to understand with a [print], so you see the entire message)

the number of cols of the matrix output by [pix_multiblob] is fixed (8
iirc), the number of rows is variable and equals the number of detected
blobs.
so [pd showblob 1] just discards the selector "matrix" and the 1st 2
values of the remaining list (the #rows & #cols) and unpacks the next 8
elements; the rest is discarded.

using iemmatrix will really help you a lot with the matrix-messages.

> Another problem is "pix_blobtracker" object are not running in my computer.

[pix_blobtracker] uses iemmatrix for further processing; you need to
have this library installed (and loaded) to make use of [pix_blobtracker].

> 
> Thanks for your lights and sorry to my poor english!

probably it might be good to add an option to [pix_multiblob] which
would output the data in a more simple (though less compact) format.

mfg.asdr
IOhannes

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