hello im a beginner with pute data and i want to do this :
my project is to make a small piano who has 3 keys using the webcam.
3 keys are papers of 3 colors and each color has a sound, and each time when we put our hands on one of these papers we listen to the noise of this paper

help me !!

I'm not into pix stuff very much but I guess it can be done.
I don't know how to do it with colours but maybe you can try with fiducials and [pix_fiducialtrack] - http://reactivision.sourceforge.net/

each fiducial triggers a sound when the contact with the cam is lost. The concept is the same...
good luck and happy new year

Oh, hey check out [pix_blob] and [pix_multiblob]. They may allow you to track the hand. The colors swatches are in particular places? then follow the hand to the three screen coordinates.

yes the colors swatches are in particular places, and when our hand are over the color then we can look just the 2 other color because our hand is in black like the surface

help me im so beginner at puredata

I would go for OpenCV objects. The can be used in many ways. I have some experience in this field and can tell you, that the task you want to accomplish could turn out quite difficult, depending on how "fast and intuitive" you want to play your piano. Main reason for that are delays and detection errors due to lighting etc. etc... but nonetheless it's a world of fun

There you go: http://hangar.org/wikis/lab/doku.php?id=start:puredata_opencv

My approach for your idea would be(schematic):

[pix_video]
|
[pix_opencv_colorfilt 255 0 0 20] // for red, but i have not tested those values!
|
[pix_opencv_contours_boundingrect]
|
[... here comes the complicated(progamming-wise) part, where i would filter out detected rectangles that are smaller than the full size]

please post your patch, if you suceed to make something great

I have not yet found the solution !! ( I'm so sad !

feel free to share the patch

i don't understand how to do it !! I'm still a beginner...

where exactly do you have problems?

I just know how i open the webcam and how i put the 3 colors...
i know nothing other....

Did you install the opencv objects? if yes, are they working?

Hi, I think that you can check with the webcam (via processing for example) if the hand of the user is in the position of the desired color, and if it is the case, trigger a sound with puredata. So you need can connect both softwares via OSC. Send osc from processing when a finger is in the place and receive it in puredata and play the sound.

Good luck, rojele