5 ms·

Opensource tool to create slowmotion videos from your footage

149 points by mars 15y ago

rhizome 15y ago
What's the relationship between "optical flow" and tweening?
- jonbro 15y ago
  Optical Flow is a method for determining the movement between two or more frames of video. This data is then used for morphing the frames into one another, or moving the underlying vertexes of the textures from one position to the next.
- tycho77 15y ago
  To find optical flow, you first pick out a collection of sample points in frame A. What constitutes a good sample point depends on your specific algorithm, although generally speaking you pick "corners". In OpenCV, you can easily do this by calling cvGoodFeaturesToTrack(). You then search for those same sample points in the successive frame B, and end up with a collection of vectors that probably represent the motion of each point. Using OpenCV, this is usually done with cvCalcOpticalFlowPyrLK(). Tweening is basically just interpolation.
  - deleted 15y ago
    [deleted]
  - karolist 15y ago
    This is very cool, thanks for that. Can we run this on a GPU? If not, how feasible would dense optical flow running on cpu be in terms of speed to convert short non-hd videos?
rbanffy 15y ago
I always like to joke that, with proprietary software, you get the best developers money can buy, but with free and opeen-source software, you get he best developers money can't buy. It's an impressive program. Simon deserves a lot of credit and gratitude for giving it to the world.
jamesmcintyre 15y ago
this is a beautiful piece of software! Thanks simon!
RobLach 15y ago
The output is surprisingly good. I am impressed.
ottaky 15y ago
Gaaagh - there goes my weekend.
IanDrake 15y ago
Is there a command line interface for this app? I'd like to batch the creation of clips using different settings and maybe make a service out of it.
inexplicable 15y ago
The results from the videos are excellent! I am truly impressed. Will try this out during the weekend.
config_yml 15y ago
I was kind of surprised he did not win at the swiss open source awards. Slowmo was truly the most impressive thing by far.
qas1981 15y ago
This is quite amazing! I was thinking if you could use this application with a video based security could you reduce the amount of disk space required. Thoughts? I'm sure there are other applications as well
- jmah 15y ago
  That makes me shudder. Security footage "compressed" this way wouldn't stand up in court (I hope); did the guy on the tape really do that, or did the algorithm just fill it in?
- secretbatcave 15y ago
  Sadly its only interpolating the motion between frames, so you don't get back any new information. Also optical flow really doesn't handle occlusions very well, so if one thing obscures another you'll get lots of artifacts.
siculars 15y ago
Fantastic. Now that's someone/something I would put in the "real software engineer" category. None of this web2.0 mumbojumbo.

149 points by mars 15y ago

rhizome 15y ago

What's the relationship between "optical flow" and tweening?

jonbro 15y ago
Optical Flow is a method for determining the movement between two or more frames of video. This data is then used for morphing the frames into one another, or moving the underlying vertexes of the textures from one position to the next.
tycho77 15y ago
To find optical flow, you first pick out a collection of sample points in frame A. What constitutes a good sample point depends on your specific algorithm, although generally speaking you pick "corners". In OpenCV, you can easily do this by calling cvGoodFeaturesToTrack(). You then search for those same sample points in the successive frame B, and end up with a collection of vectors that probably represent the motion of each point. Using OpenCV, this is usually done with cvCalcOpticalFlowPyrLK(). Tweening is basically just interpolation.
- deleted 15y ago
  [deleted]
- karolist 15y ago
  This is very cool, thanks for that. Can we run this on a GPU? If not, how feasible would dense optical flow running on cpu be in terms of speed to convert short non-hd videos?

rbanffy 15y ago

I always like to joke that, with proprietary software, you get the best developers money can buy, but with free and opeen-source software, you get he best developers money can't buy. It's an impressive program. Simon deserves a lot of credit and gratitude for giving it to the world.

jamesmcintyre 15y ago

this is a beautiful piece of software! Thanks simon!

RobLach 15y ago

The output is surprisingly good. I am impressed.

ottaky 15y ago

Gaaagh - there goes my weekend.

IanDrake 15y ago

Is there a command line interface for this app? I'd like to batch the creation of clips using different settings and maybe make a service out of it.

inexplicable 15y ago

The results from the videos are excellent! I am truly impressed. Will try this out during the weekend.

config_yml 15y ago

I was kind of surprised he did not win at the swiss open source awards. Slowmo was truly the most impressive thing by far.

qas1981 15y ago

This is quite amazing! I was thinking if you could use this application with a video based security could you reduce the amount of disk space required. Thoughts? I'm sure there are other applications as well

jmah 15y ago
That makes me shudder. Security footage "compressed" this way wouldn't stand up in court (I hope); did the guy on the tape really do that, or did the algorithm just fill it in?
secretbatcave 15y ago
Sadly its only interpolating the motion between frames, so you don't get back any new information. Also optical flow really doesn't handle occlusions very well, so if one thing obscures another you'll get lots of artifacts.

siculars 15y ago

Fantastic. Now that's someone/something I would put in the "real software engineer" category. None of this web2.0 mumbojumbo.