opencv object detection with my own features

asked 2015-10-21 08:53:47 -0600

I want to use openCV objet detection model with my own features "fourrier descriptors". I know how to do this using the haar features ( the Viola & Jones method ), now i want to use the same processus using my own customised features. Do you have any idea plz? Thanks for your help, Amine.

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1

maybe you could show, how your 'fourier descriptors' look like ?

is there any code ?

apart from descriptors, you'll probably need a classification/learning mechanism (like AdaBoost used with haar/lbp cascades), also some 'sliding window' technique or such. what are your plans here (so far..) ?

berak gravatar imageberak ( 2015-10-21 08:59:42 -0600 )edit

I am also interested in this

thdrksdfthmn gravatar imagethdrksdfthmn ( 2015-10-21 09:10:37 -0600 )edit

my fourier descriptors are computed globaly in the image, i.e, for each image, one vector descriptor is computed, so for a database of 2500 faces , i have 2500 fourier descriptors ( vector size = 1x4417 ). now, i'm blocked at the training classifier step. thanks

amine87 gravatar imageamine87 ( 2015-10-21 09:28:04 -0600 )edit

again, please show us, how you calculate those.

then - what exactly is your goal ? detection (face or not) ? classification (who is it) ?

what did you try for classification so far ?

berak gravatar imageberak ( 2015-10-21 09:30:32 -0600 )edit
1

i have already apply this descriptors in a svm context for classification, now my goal is to apply them in object detection context. To compute these descriptors : - i compute the ffteshift of the input image, then i evaluate this fftshift in a regular hexagonal grid points, for each hexgon 6 points, i get a W(f) vector dim 6x2, finally the combination of theses vectors give the invariant descriptor of the image, and it's a vector dim 1xN. (sorry, i can't share the code of computing these descriptors now, it will be after submitting the paper) I tested my descriptors against coil and orl database for classification, and i got accuracy = 97% good classification. Now the next step is to test them in object detection context. Thanks

amine87 gravatar imageamine87 ( 2015-10-21 10:02:56 -0600 )edit
1

So your question becomes "How to use Ada Boost cascades on Fourier features?"

thdrksdfthmn gravatar imagethdrksdfthmn ( 2015-10-21 10:13:14 -0600 )edit

Exactly !!

amine87 gravatar imageamine87 ( 2015-10-21 10:49:44 -0600 )edit
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I am afraid you need to modify the cascade code from OpenCV, for that... Or make your own AdaBoost

thdrksdfthmn gravatar imagethdrksdfthmn ( 2015-10-22 02:31:27 -0600 )edit

can you tel me more about how to modifiy the cascade and the training classifier code of opencv, some ideas, ... please

amine87 gravatar imageamine87 ( 2015-10-22 03:32:50 -0600 )edit
1

if you want my 2ct, - stay away from the rather outdated and total messy cascade_training code.

rather build your own on top of cv::Boost

berak gravatar imageberak ( 2015-10-22 03:38:39 -0600 )edit