I'll update the helpfile for [pix_motion_sector] to include a subpatch that does the same thing with [pix_crop], [pix_movement], and [pix_dump]. I think I might also change the source and try taking the distance between current/previous frames using all RGB info instead of a greyscale approximation. The speed issue aside, that may be a significant difference from [pix_movement] worth investigating.
On Fri, May 14, 2010 at 8:43 AM, Hans-Christoph Steiner <h...@at.or.at> wrote: > > I'd love to see an example implementation of this as a patch, if anyone is > up for it. A lot of students ask me for this kind of video tracking. It > would be good to add to the video tracking examples. > > .hc > > On May 14, 2010, at 10:11 AM, Jack wrote: > >> Le vendredi 14 mai 2010 à 06:49 -0700, William Brent a écrit : >>> >>> I implemented Miller's phase vocoder from the documentation in C and >>> was amazed to see that the CPU load was exactly the same. So much for >>> improving efficiency... But I have seen a big difference for >>> traversing tables and lists. The process of summing the elements in a >>> large table is much faster in an extern than with an [until] loop. >>> >>> In the case of [pix_motion_sector], what's the easiest way to >>> duplicate the functionality of reporting % of pixels changed in the >>> region? Is there an obvious way to count up the number of pixels that >>> crossed [pix_movement]'s threshold in the cropped region? >> >> [pix_dump] ? Maybe a faster method ? >> ++ >> >> Jack >> >> >>> >>> >>> >>> 2010/5/14 IOhannes m zmölnig <zmoel...@iem.at>: >>>> >>>> -----BEGIN PGP SIGNED MESSAGE----- >>>> Hash: SHA1 >>>> >>>> Jaime Oliver wrote: >>>>> >>>>> On Thu, May 13, 2010 at 7:40 PM, Mathieu Bouchard >>>>> <ma...@artengine.ca>wrote: >>>>> >>>>>> On Thu, 13 May 2010, William Brent wrote: >>>>>> >>>>>> Yes - it's exactly that: an adaptation of pix_movement that lets you >>>>>>> >>>>>>> specify an area to analyze. That way you can use several instances >>>>>>> to >>>>>>> create multiple regions for triggering different events. I haven't >>>>>>> looked >>>>>>> at this in two years! I'll take a look at the helpfile and see >>>>>>> what's >>>>>>> missing/unclear. >>>>>>> >>>>>> what's the difference between that, and using [pix_crop] and >>>>>> [pix_movement] >>>>>> with [pix_separator] ? >>>>>> >>>>> >>>>> Please correct me if I'm wrong, >>>>> Doesn't having these as externals instead of abstractions, make it >>>>> significantly faster/efficient? >>>>> particularly if you have many of them? >>>>> >>>> >>>> no not necessarily. >>>> the overhead for message communication between objects is usually quite >>>> small, compared to the pixel operations. >>>> >>>> you would only need [pix_crop]->[pix_movement] without the >>>> [pix_separator] (since the crop will have to allocate a new image >>>> anyhow), thus no need for the extra copying of data. >>>> >>>> the only speedup you could expect from pix_motion_sector (i haven't >>>> looked at the code), is that you wouldn't have to copy the data for >>>> cropping at all, but only use the pixels in the ROI. >>>> >>>> >>>> as for williams argument, that you need less objects, i would suggest >>>> looking into abstractions :-) it's definitely less lines of code (at a >>>> minimum 10 lines of Pd code) and still only a single object... >>>> >>>> mfgasdr >>>> IOhannes >>>> >>>> >>>> >>>>> best, >>>>> >>>>> J >>>>> >>>>>> _ _ __ ___ _____ ________ _____________ _____________________ ... >>>>>> | Mathieu Bouchard, Montréal, Québec. téléphone: +1.514.383.3801 >>>>>> _______________________________________________ >>>>>> Pd-list@iem.at mailing list >>>>>> UNSUBSCRIBE and account-management -> >>>>>> http://lists.puredata.info/listinfo/pd-list >>>>>> >>>>>> >>>>> >>>>> >>>>> >>>>> >>>>> ------------------------------------------------------------------------ >>>>> >>>>> _______________________________________________ >>>>> Pd-list@iem.at mailing list >>>>> UNSUBSCRIBE and account-management -> >>>>> http://lists.puredata.info/listinfo/pd-list >>>> >>>> -----BEGIN PGP SIGNATURE----- >>>> Version: GnuPG v1.4.10 (GNU/Linux) >>>> Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org >>>> >>>> iEYEARECAAYFAkvtC0wACgkQkX2Xpv6ydvTVNwCgot+wBAkpacUIHBFR3Fg5OmWV >>>> xhAAoITZ7wN077ETVr58rSVE9iunYybB >>>> =jYk3 >>>> -----END PGP SIGNATURE----- >>>> >>>> _______________________________________________ >>>> Pd-list@iem.at mailing list >>>> UNSUBSCRIBE and account-management -> >>>> http://lists.puredata.info/listinfo/pd-list >>>> >>> >>> >>> >> >> >> >> _______________________________________________ >> Pd-list@iem.at mailing list >> UNSUBSCRIBE and account-management -> >> http://lists.puredata.info/listinfo/pd-list > > > > ---------------------------------------------------------------------------- > > "We have nothing to fear from love and commitment." - New York Senator Diane > Savino, trying to convince the NY Senate to pass a gay marriage bill > > -- William Brent www.williambrent.com “Great minds flock together” Conflations: conversational idiom for the 21st century www.conflations.com _______________________________________________ Pd-list@iem.at mailing list UNSUBSCRIBE and account-management -> http://lists.puredata.info/listinfo/pd-list