[PD] live video tracking w/ Gem

zmoelnig at iem.at zmoelnig at iem.at
Tue Oct 21 15:33:05 CEST 2003

Zitiere Hans-Christoph Steiner <hans at eds.org>:

> Gem has [pix_movement].  PDP has some movement and color tracking 
> objects also.

[pix_movement] puts the difference between two adjacent rgba-frames into the
alpha-channel of the 2nd. (i think it stores the difference into the
grey-channel for Grey-images (which is "the" channel) and into the Y-channel for

to get control-data out of this, there is the [pix_blob]-object, which does
blob-analysis (position and size of the blob, either in a single channel or in
an overall of all channels).
this way, you can do color-tracking too, although i admit it is a bit complicated.
normally i'd do this with a combination of [pix_rgb2hsv] (to transform into a
format with more meaningful in terms of color channels),
[pix_curve]/[pix_bitmask] (to mask unwanted values) and [pix_blob].
i think it might be a bit easier in yuv-space (but i am no specialist in there)

however, the PoDoP-part of pdp is surely more sophisticated.


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