Turn off anti-aliasing when rotating / scaling etc... ?

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Level 1

9 points

Turn off anti-aliasing when rotating / scaling etc... ?

Hi

Is this possible? I've got a clip which i'm rotating a little. It's deliberately pixellated and rough looking, and once rotated FCP adds anti-aliasing to the image. I know this is usually helpful but is there a way to turn it off? i've tried sharpening but it's not the same

Hope someone can help

macbook pro, Mac OS X (10.5.6)

Posted on Nov 23, 2009 4:52 AM

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Answer 1

sborelli Author

Level 1

9 points

Nov 23, 2009 5:08 AM in response to Nick Holmes

Many thanks for your response. It's not what I'm getting at though - an edge feather doesn't maintain sharpness throughout an image, it feathers the edges of a frame.

Anti-aliasing is not innately how video works - it's something final cut applies when a user rotates an image, scales it etc... so it doesn't have sharp pixellated edges and so forth, and the image remains clean. This is usually desirable to keep the image nice. In this case digital noise is a big part of the look of the shot, but it is eliminated by the softening which comes from anti-aliasing.

I can take it into after effects and flick the anti-aliasing switch off, which achieves my goal, but wondered if it could be done in FCP, to save time and rendering.

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Answer 2

Nick Holmes

Level 7

30,018 points

Nov 23, 2009 5:02 AM in response to sborelli

is there a way to turn it off?

Not really, thats how video works. You might try adding a slight Edge Feather in the Viewer's Motion tab > Crop settings.

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Answer 3

Tom Wolsky

Level 10

152,777 points

Nov 23, 2009 5:48 AM in response to sborelli

Are you looking at the rendered output on a video monitor?

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Answer 4

sborelli Author

Level 1

9 points

Nov 23, 2009 6:00 AM in response to Tom Wolsky

Hi

Thanks. It's not rendered output I'm on the timeline, but I tested and rendered output is the same.
I'm on a 22inch LCD.

It's just the way FCP works that it applies slight anti-aliasing when you rotate a video track / layer. Only with this project, there's a fine digital noise which I need to keep, and it's just lost when this AA is put on.

In after effects there's a 'draft' setting - it doesn't add any anti-aliasing to manipulated video layers. I was wondering if there's an equivalent in FCP, because otherwise i have to take 30 mins footage into AE, since it all needs to be rotated without any soft AA being added.

It seems maybe there isn't I've been hunting for ages!

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Answer 5

Tom Wolsky

Level 10

152,777 points

Nov 23, 2009 6:20 AM in response to sborelli

What format are you working in? If you're doing compositing and effects you need to work in a high resolution format.

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Answer 6

sborelli Author

Level 1

9 points

Nov 23, 2009 6:29 AM in response to sborelli

Thanks for your response. I hope I don't sound dismissive, but this isn't the issue.

I do a lot of effects work, but this is a deliberately low-quality video. I'm not doing any compositing at all. Poor quality, sharp digital noise in the image is the look of the piece! I'm simply rotating a piece of video (motion tab / rotation) by a few degrees, to correct for tripod error. When that video is rotated, FCP automatically applies AA to it by default. This ruins my sharp digital noise look because it softens it to a visible extent.

This is a standard feature in FCP. There should be an option in FCP to turn it off, either I can't find it or it's not there. I think I'll import to After Effects and render at draft quality without the AA.

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Answer 7

Tom Wolsky

Level 10

152,777 points

Nov 23, 2009 6:31 AM in response to sborelli

If you want this, you should use Feedback. You can also render at reduced quality in FCP sequence settings.

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Answer 8

Nov 23, 2009 6:33 AM in response to sborelli

There's a high Motion filtering quality setting in the Sequence's setting's Video Process tab.. might fool around with that...?

Jerry

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Answer 9

sborelli Author

Level 1

9 points

Nov 23, 2009 6:47 AM in response to sborelli

Thanks for the ideas. Jerry, I tried that, it's exactly the setting I was hunting for - however FCP's 'Fastest (linear)' setting still softens the image out... I think I'll have to go the After Effects route

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Answer 10

Andy Mees

Level 6

12,610 points

Nov 23, 2009 6:58 AM in response to sborelli

Unfortunately, whenever rotation is applied, the Motion Filtering Quality setting is entierly bypassed ... with rotation applied to a clip then regardless of setting the Motion Filtering Quality for that clip defaults to Fastest (aka fast, low-quality motion transformations on your clips). Sad but true.

http://documentation.apple.com/en/finalcutpro/usermanual/chapter85_section26.html

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Answer 11

Nov 23, 2009 10:10 AM in response to Andy Mees

Bummer...

Ya learn something every day.

Jerry

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Answer 12

Studio X

Level 7

27,229 points

Nov 23, 2009 10:16 AM in response to Jerry Hofmann

If everyone will please stop gnashing teeth over FCP's failings for a minute and think about what is really going on with a video pixel grid, it becomes obvious that FCP has to do SOMETHING to deal with the grid mismatch that rotation causes. It is NOT a one to one translation.

x

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Answer 13

sborelli Author

Level 1

9 points

Nov 23, 2009 10:21 AM in response to sborelli

Absolutely. Final Cut renders everything out very nicely, for most projects things would look awful if there were no interpolation when you apply rotations and scaling. Just doesn't work when you occasionally want the defects, as in my project! But it's very rare to want that

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Answer 14

Studio X

Level 7

27,229 points

Nov 23, 2009 10:41 AM in response to sborelli

Nick is correct, it is a result of the transposition of the pixels. They HAVE to be blurred because the rotated raster in effect creates a blended pixel mashup. It is a simple function of the mathematics of the operation.

If the visual integrity of your project is of overriding importance you have two options:

1. tilt the screen (and projector if part of the display package) the appropriate number of degrees so that when viewed the images within the angled screen appear to be correct or
2. tilt the chairs/couches of the viewers so that their head angle corrects for the screwed up image.
or
3. add back in the video noise in (we'll fix it in) post.

Oh, and don't forget to give the camera operator and production supervisor a love tap around the the head and shoulders for such a rookie mistake. This would not have happened if you had a monitor on the set.

x

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Answer 15

Nov 23, 2009 10:50 AM in response to Studio X

Directors that don't use headphones and a watch a monitor fed from the camera during the shoot are making a big mistake... Not always possible of course, but most of the time they are...

Jerry

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