how is it possible to use several cameras, correct perspective on each, make a big picture with blending and then tracking on that big picture with CCV ? this have been done with Pd and pix_opencv and works great (at least if you're not using a cheap V4L2 cam with buggy drivers)
-- do it yourself http://antoine.villeret.free.fr 2013/4/18 John Harrison <[email protected]> > FWIW I had just the opposite experience with CCV. CCV has built-in > background adaptive subtraction, smoothing, highpass filter, gain, > contrast, etc. all tweakable. It also tracks blobs uniquely as the original > poster is wanting, which is why I thought of it for their needs. I used > [pix_blobtracker] before and it works OK but I found CCV to be overall a > more robust solution than anything I could efficiently come up with. > > I use CCV at 60fps 640x480 w/ a ps3eye on ubuntu 10.04 64 bit and the CPU > load is not significant and reduced from my original Pd-only solution. My > CCV/Pd patch has been on exhibit 24/7 for 5 months now without issue so it > also seems stable. I use CCV version 1.4. I also used CCV on another > exhibit with a Win7 64 bit system and that ran for months as well without > issue. That might have been version 1.5 but I don't remember for sure. I > also know there's a newer version of CCV supporting multiple cameras now, > and I have not had experience with this. > > Maybe I'm not understanding the flexibility you are looking for that CCV > is not offering you. All I can imagine is that you can't find a way to > change the order of the filtering. I'm not sure that's something you'll > find you actually need though to improve the result of the blob tracking. > > Just my $.02. > > -John > > On Thu, Apr 18, 2013 at 8:42 AM, Antoine Villeret < > [email protected]> wrote: > >> i tried CCV one time but i had some driver and performance issues >> moreover, i can't find an easy way to tune the processing chain >> pd is more flexible but, i agree, could be harder >> >> -- >> do it yourself >> http://antoine.villeret.free.fr >> >> >> 2013/4/18 John Harrison <[email protected]> >> >>> I'm not totally clear on the big picture here but it could be you might >>> save yourself a lot of time and effort doing your blob tracking with >>> Community Core Vision (CCV) then sending the blob data to Pd through OSC. >>> After initially doing my blob tracking in Pd only (which did work), I >>> switched to this CCV --> Pd approach and got better results because of all >>> of the built-in filtering etc. that is provided with that open-source >>> cross-platform software. >>> >>> -John >>> >>> >>> On Thu, Apr 18, 2013 at 5:22 AM, Ska Frenz <[email protected]> wrote: >>> >>>> Hi, thank you for the suggestions, I'll check openCv. Can you explain >>>> how to use "morphological filters" to clear up the noise in the image? Are >>>> there examples around? Also, could you please explain me better what do you >>>> mean with "adaptive background subtraction method"? >>>> >>>> Thank you for your time :) >>>> >>>> francesco >>>> >>>> >>>> 2013/4/17 Antoine Villeret <[email protected]> >>>> >>>>> hi, >>>>> >>>>> the segmentation method (how you extract what is your interest from >>>>> the rest of the image) is very critical in video tracking >>>>> background subtraction is a basic way to extract blob and it works >>>>> only in certain conditions of light (if you want to track something >>>>> outdoor, you should use an adaptive background subtraction method) >>>>> moreover, there is no general method to do video tracking, it depends >>>>> on what you want to track and how it is filmed >>>>> >>>>> so, the first thing is to have a good image, with not too much >>>>> lighting changes, good contrast between background and features to track >>>>> then you can start thinking about segmentation, and the >>>>> segmentation accuracy depends on the quality of the video >>>>> you may need to do something more than just background subtraction, >>>>> for example, you could apply some morphological filter to remove noise >>>>> after that, you can start tracking >>>>> you could also apply a threshold on the blob size to not track very >>>>> small blob >>>>> blob of interest are often surrounded by very small blobs due to >>>>> segmentation noise >>>>> >>>>> but you can have a look at pix_opencv objects, >>>>> there is [pix_opencv_blobtrack] which implements a whole processing >>>>> chain, including foreground extractor, blob detector, blob tracker and >>>>> follower >>>>> I'm not sure it's included in pd-extended, but you can find some >>>>> binaries on build server >>>>> >>>>> hope this help >>>>> >>>>> antoine >>>>> >>>>> >>>>> -- >>>>> do it yourself >>>>> http://antoine.villeret.free.fr >>>>> >>>>> >>>>> 2013/4/17 Ska Frenz <[email protected]> >>>>> >>>>>> Hi everyone, this is my first time on the pd-list so I hope I won't >>>>>> do anything wrong. >>>>>> I'm writing here to get some help about pd tracking objects >>>>>> (pix_blob..). I'm using the background subtraction method, to track >>>>>> objects >>>>>> and I need help to understand how I can track multiple objects with >>>>>> multiples different blobs. I'm trying the pix_multiblob and yes, it show >>>>>> 2 >>>>>> blobs..but they track the same object. Then basically I do not understand >>>>>> how can I make the first blob to follow just one object for all the time >>>>>> that specific object is inside the webcam rectangle, and the second blob >>>>>> to >>>>>> track another separate object. I cannot find any material that clearly >>>>>> talks about this.I attached the patch I'm working on. I'd love to see >>>>>> some >>>>>> well-explained examples if you know where to get them. >>>>>> Thank you very much for your help :) >>>>>> >>>>>> Francesco >>>>>> >>>>>> _______________________________________________ >>>>>> [email protected] mailing list >>>>>> UNSUBSCRIBE and account-management -> >>>>>> http://lists.puredata.info/listinfo/pd-list >>>>>> >>>>>> >>>>> >>>> >>>> _______________________________________________ >>>> [email protected] mailing list >>>> UNSUBSCRIBE and account-management -> >>>> http://lists.puredata.info/listinfo/pd-list >>>> >>>> >>> >> >
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