Re: Motion Blur
Re: Motion Blur
- Subject: Re: Motion Blur
- From: Darrin Cardani <email@hidden>
- Date: Mon, 14 Feb 2005 09:51:45 -0600
At 1:10 AM -0800 2/14/05, Lorenzo <email@hidden> wrote:
I cannot reach a good resut when I export my OpenGL animation (which really
are several still images) to a QT movie with motion blur. My OpenGL
animation runs at 60 FPS, while I export it to a QT movie at 30 FPS.
So basically, I take the even frames (2nd, 4th, 6th...) with 50% alpha, and
I add them to the odd frames (1st, 3rd, 5th...) which I leave 100% alpha. SO
here I sign QT1 as the QT frame 1, and gl1 the openGL frame 1.
QT1: gl1 at 100% + gl2 at 50%
QT2: gl3 at 100% + gl4 at 50%
QT3: gl5 at 100% + gl6 at 50%
... and so forth
But the result is not good. Even if the motion blur is visible, I still see
the resulting whole image half unfocused and a little bit with a strobo
effect. Wha can I do to make it better?
The first thing I would try is mixing both frames at 50% each, rather
than 1 at 100% and the other at 50%. That's closer to what the eye
would experience in real life, I'd think.
Since you're working with still frames, could you generate more
frames in between? For example, can you export 120 fps and then
combine 4 frames at 25% each for each output frame?
The other way you could do it is to post-process your images,
depending on what the motion is like. If the motion blur is caused by
camera movement, you can use standard image processing techniques for
the motion blur, such as rotating or skewing the entire frame,
blurring in just the horizontal or just the vertical direction, then
skewing or rotating back by the opposite amount. However, if each
object is moving independently in different directions, this won't
give you the correct results. (Though it may still be good enough for
your purposes. Since you didn't say what your purposes are, I don't
know if that's the case or not.)
Darrin
--
Darrin Cardani - email@hidden
President, Buena Software, Inc.
<http://www.buena.com/>
Video, Image and Audio Processing Development
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