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If you're dumb like me and don't realize what's going on at first: the source clip was of some guys talking about a game being shown on a video monitor at an an

by abalone 12y ago

If you're dumb like me and don't realize what's going on at first: the source clip was of some guys talking about a game being shown on a video monitor at an angle. But he just wanted to see the game, not the guys. So he extracted the video and made it fullscreen. He did it by writing a script to turn every frame into a PNG, run them through an image-processing tool, then recompress a new video. Thankfully the monitor did not move much so some fixed distortion parameters worked.

sillysaurus3 12y ago
Thankfully the monitor did not move much so some fixed distortion parameters worked. Even if the monitor moved alot (http://hyperboleandahalf.blogspot.com/2010/04/alot-is-better-than-you-at-everything.html http://hyperboleandahalf.blogspot.com/2010/04/alot-is-better...) it'd be fairly easy to write an algorithm to detect the four corners of the video. You basically want to throw some edge detection at it, and then look for anything that seem like corners.
- girvo 12y ago
  > You basically want to throw some edge detection at it, and then look for anything that seem like corners. Which, if you're a web dev like I am, seems scary at first, especially when you're (like me) lacking a CS education. However, as it turns out, understanding edge detection and Haar cascades (for feature detection, that was the problem I was solving) enough to be dangerous with OpenCV is surprisingly easy! I recently built some facial feature detection stuff in it that is in production right now, and it only took me a couple weeks :) So, have a play!
  - deleted 12y ago
    [deleted]
- krick 12y ago
  Right, but then you wouldn't use imagemagick for the task anymore...
- lhl 12y ago
  You could also probably run an OOTB algorithm to generate the tracking: http://opencv-python-tutroals.readthedocs.org/en/latest/py_tutorials/py_video/py_meanshift/py_meanshift.html http://opencv-python-tutroals.readthedocs.org/en/latest/py_t... or even http://opencv-python-tutroals.readthedocs.org/en/latest/py_tutorials/py_video/py_lucas_kanade/py_lucas_kanade.html http://opencv-python-tutroals.readthedocs.org/en/latest/py_t...
pronoiac 12y ago
This is a built-in filter with Cinelerra, with no intermediate files required.
magoghm 12y ago
Some guys talking about a game: Shigeru Miyamoto and Eiji Aonuma talking about the new Zelda game.

by abalone 12y ago

sillysaurus3 12y ago

Thankfully the monitor did not move much so some fixed distortion parameters worked. Even if the monitor moved alot (http://hyperboleandahalf.blogspot.com/2010/04/alot-is-better-than-you-at-everything.html http://hyperboleandahalf.blogspot.com/2010/04/alot-is-better...) it'd be fairly easy to write an algorithm to detect the four corners of the video. You basically want to throw some edge detection at it, and then look for anything that seem like corners.

girvo 12y ago
> You basically want to throw some edge detection at it, and then look for anything that seem like corners. Which, if you're a web dev like I am, seems scary at first, especially when you're (like me) lacking a CS education. However, as it turns out, understanding edge detection and Haar cascades (for feature detection, that was the problem I was solving) enough to be dangerous with OpenCV is surprisingly easy! I recently built some facial feature detection stuff in it that is in production right now, and it only took me a couple weeks :) So, have a play!
- deleted 12y ago
  [deleted]
krick 12y ago
Right, but then you wouldn't use imagemagick for the task anymore...
lhl 12y ago
You could also probably run an OOTB algorithm to generate the tracking: http://opencv-python-tutroals.readthedocs.org/en/latest/py_tutorials/py_video/py_meanshift/py_meanshift.html http://opencv-python-tutroals.readthedocs.org/en/latest/py_t... or even http://opencv-python-tutroals.readthedocs.org/en/latest/py_tutorials/py_video/py_lucas_kanade/py_lucas_kanade.html http://opencv-python-tutroals.readthedocs.org/en/latest/py_t...

pronoiac 12y ago

This is a built-in filter with Cinelerra, with no intermediate files required.

magoghm 12y ago

Some guys talking about a game: Shigeru Miyamoto and Eiji Aonuma talking about the new Zelda game.