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Gesture Recognition with Line Integrals

justinmeiners.github.io

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Re: Gesture Recognition with Line Integrals

#3

Post by rg2004 »

I created a method similar to this one for curve extrapolation based on sample curves. I took the second derivative of each point on the training data, added it's contributions to a vector field.

To extrapolate, you can take 'position' and 'velocity' of live data and integrate over the vector field to produce an extrapolation. I enjoyed the project and it worked fairly well. I think there's plenty of room for extension around this method.

Re: Gesture Recognition with Line Integrals

#4

Post by gnramires »

DennisP wrote: post #2

Cool but how is the math used to recognize gestures?

It appears to be a dot product of a vector field and the curve vector (i.e. a line integral).

I think this approach can't handle certain cases where a path is retraced in opposite directions, like with the handwritten letter 't' or 'i'. Perhaps curvature integrals could be added as well to improve it.

Overall seems to work quite well!

Re: Gesture Recognition with Line Integrals

#5

Post by justinmeiners »

gnramires wrote: post #4
DennisP wrote: post #2

Cool but how is the math used to recognize gestures?

It appears to be a dot product of a vector field and the curve vector (i.e. a line integral). I think this approach can't handle certain cases where a path is retraced in opposite directions, like with the handwritten letter 't' or 'i'. Perhaps curvature integrals could be added as well to improve it. Overall seems to work quite well!

> can't handle certain cases where a path is retraced in opposite directions

It does ok if there is only a small part that retraces, but you're exactly right.

Re: Gesture Recognition with Line Integrals

#9

Post by justinmeiners »

mgraczyk wrote: post #8

Not sure what is intended, but it seems to have some bugs? https://assets.opentoken.com/sha256/N1ShZ7kcVmH_-auZEGaGOS_b... Ah nevermind, it's matching the curve against template fields so it makes sense that it would show the best match even when the match is poor.

> best match even when the match is poor.

Yeah, a real application could have a score threshold.

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