Motion Estimation with Optical Flow • Hacker News Board

Re: Motion Estimation with Optical Flow

#21

Post by chuanenlin » Tue, Apr 30, 2019, 7:31 AM UTC

Darkphibre wrote: post #4

I've dabbled with optical flow for a hobby side project (using the Windows ShaderEffectClass of all things). I worked on the Kinect back in the day; while I was primarily audio, I had a fascination of applying DSPs to two- and three-dimensional temporal data. I've always felt that it was a missed opportunity to tap into temporal information for entity recognition. I'm excited to see this take hold!

@Darkphibre, wonderful background! Yes, and optical flow + recent advancements in deep learning is also certainly something exciting to see flourish! Action recognition seems like a promising research area (https://research.google.com/ava/ CVPR '18).

Re: Motion Estimation with Optical Flow

#22

Post by haxiomic » Tue, Apr 30, 2019, 7:32 AM UTC

chuanenlin wrote: post #19

haxiomic wrote: post #3

Back in 2008 there was an amazing demo of realtime dense optical flow on a GPU[0] but all the links are dead now. I've searched hard for another comparable implementation since then but had no luck. Does anyone have a hint on what technique they might have used? [0] https://www.youtube.com/watch?v=ssINeWRb58M

Hi @haxiomic, I'm the author of the article - thanks for reading! Several more recent approaches of computing optical flow with CNNs such as FlowNet2 (CVPR '17) ( https://github.com/lmb-freiburg/flownet2 ) should also be runnable on video or live webcam feed.

Thanks @chuanenlin, I found the article very informative at easy to digest :)

Thanks for the link - can’t wait to have a play with it!

Re: Motion Estimation with Optical Flow

#23

Post by haxiomic » Tue, Apr 30, 2019, 11:50 AM UTC

rjeli wrote: post #10

tbirdz wrote: post #6

Earlier quoted context omitted.

We're doing this with H.264 at work. Pretty useful since we need to generate the encoded stream anyway, so now we get motion estimation for free.

Awesome. Which encoder provides this? Can you pull it from cuvid?

NVidia has some example code for getting the motion vectors during video encoding

https://github.com/NVIDIA/video-sdk-samples/blob/master/Samp...

Re: Motion Estimation with Optical Flow

#24

Post by rjeli » Tue, Apr 30, 2019, 11:48 PM UTC

haxiomic wrote: post #23

rjeli wrote: post #10

Earlier quoted context omitted.

Awesome. Which encoder provides this? Can you pull it from cuvid?

NVidia has some example code for getting the motion vectors during video encoding https://github.com/NVIDIA/video-sdk-samples/blob/master/Samp...

Thank you!