Hi list,
I' trying to make an effect on a live camera feed with GEM for an installation in which only persons who move appear on a kind of video mirror, as chameleonTv of effecTv (http://effectv.sourceforge.net/chameleon.html) I tryed severals ways :
with pix_background and pix_blob, modulating the alpha value of the
rectangle on which the video is textured in function of the quantity of movement but if one person moves, everybody appears.
with pix_multiblob and combination of pix_image pix_rectangle and
pix_mask, the [pix_multiblob 2] seems to eat all the processor, even if I [pix_resize 320 240] the image before the multiblob.
accumulating many (25) pix_movement and using the result by
pix_masking it with the live feed dig a hole in the person that moves a little. Maybe I did not the "average" of alpha channel of the 25 previous frame as I thought, due to the fact that pix_movement works on the previous frame ? is there a better way with opengl instructions ? I tryed to look in that direction but I didn't manage yet to find how to analyze and affect the pixels of a live feed.... thanks for any advice benjamin
for the tech note : the video feed is from a PCI capture card (AlchemyTv) connected in s-video to a dv camera with [pix_video 720 576] on a G5 10.4 Pd ext7, for the first trial, I manage to mix this video feed with another DV camera connected in firewire, putting into a buffer an image background, filling and playing another buffer with PAL images, and playing a non compressed video of the same size >>> output on a second screen 800x600, with all that, the motion capture was really fast, only 40% of the proc used, it was really impressive (and stable), great dev work, thks