DV Info Net

DV Info Net (https://www.dvinfo.net/forum/)
-   Final Cut Suite (https://www.dvinfo.net/forum/final-cut-suite/)
-   -   Photoshop curves for Final Cut (https://www.dvinfo.net/forum/final-cut-suite/485713-photoshop-curves-final-cut.html)

Dominik Seibold October 5th, 2010 02:27 PM

Photoshop curves for Final Cut
 
I'm about to write a plugin for Final Cut which should imitate the Photoshop RGB-Curves. But I have one problem/question which I just can't get answered even with extreme googleing:
What is the interpolation-formula Photoshops curves uses to interpolate between the points?
It seems to me that Photoshops curves inpolation is both unique out of all curves out there (Apple Color, etc.) and best regarding the photographic quality compared to the effort to tweak a curve. Other implementations of such curves-tools often use interpolation-schemes like Bezier, but they feel really inadequate for this application. So I absolutely want to implement the interpolation like Photoshops curves does, but I have absolutely no idea what the formula could look like.

William Hohauser October 5th, 2010 04:49 PM

Be careful, it might be patented.

Dominik Seibold October 5th, 2010 10:06 PM

1 Attachment(s)
The plugin is now almost done. You can download and test it here:
http://www.dominik.ws/rgbcurves.zip
I also attached a screenshot of it to this post.
The only missing thing is a good interpolation between the points. Currently linear interpolation is used. If someone of you could give me a hint what kind if interpolation I should implement, I will do it! :) Please give me some feedback what you think about the plugin!

Chuck Spaulding October 6th, 2010 12:22 AM

That's a great idea. I always thought they were just B-splines. I think it would be a lot more useful if you could edit the curves directly, break them at the point so they can linear in and Bezier out.

I thought Apple started improving their graph editor, it was good for a while in variable speed, but it never really went anywhere.

Is there a high-pass filter in FCP? That's a good filter for sharpening, if your taking requests...

Dean Sensui October 7th, 2010 03:32 AM

A suggestion: Use Color.

It already has curves and is an immensely powerful color correction tool.

Dominik Seibold October 7th, 2010 05:40 AM

1 Attachment(s)
Quote:

Originally Posted by Chuck Spaulding (Post 1575997)
I always thought they were just B-splines.

Thank you! I finally discovered that Photoshops curves uses so called "natural cubic splines". I implemented them now into my plugin. Here you can download and install the result (I used fxplug sdk 1.2.5):
http://www.dominik.ws/rgbcurves.zip
Btw., a 16bit (unsigned short) per channel lookup-table is internally generated and used, so the image processing is fast and posterizing free (but not GPU accelerated right now. If you know how to write an ARB fragment shader which uses a lookup table, please let me know!).
A sreenshot is attached to this post which shows the plugin in action.
Please give me some feedback!

Quote:

Originally Posted by Chuck Spaulding (Post 1575997)
Is there a high-pass filter in FCP? That's a good filter for sharpening, if your taking requests...

What kind of high-pass filter? Like the simple sharpening filter or more like unsharp mask?

Quote:

Originally Posted by Dean Sensui (Post 1576385)
A suggestion: Use Color.

I don't like the behaviour of Colors Curves. Also I don't like to even start Color up. I think the workflow is very inconvenient.

William Hohauser October 7th, 2010 01:09 PM

Your filter sounds good but the download installer file seems to be empty, only 16k. Could you post the filter without the installer package?

Simon Denny October 7th, 2010 01:25 PM

Thanks Dominik,

Plugin works great and I like it. Is there anyway to add a point to the curve rather than adding a point as it moves. I say this because as I add a point the cure moves and I may not want to add a point in that spot.

Cheers

Dominik Seibold October 7th, 2010 01:29 PM

Quote:

Originally Posted by William Hohauser (Post 1576547)
Your filter sounds good but the download installer file seems to be empty, only 16k. Could you post the filter without the installer package?

Well, the installer isn't empty, but of course (I guess it's a trust issue) I can also give you the raw fxplug File/Folder:
http://www.dominik.ws/rgbcurves2.zip

Dominik Seibold October 7th, 2010 01:45 PM

Quote:

Originally Posted by Simon Ash (Post 1576554)
Is there anyway to add a point to the curve rather than adding a point as it moves.

I just added this feature. With the right mouse button you can now add a point which initially doesn't alter the curve (x value comes from your mouse, y value from the current curve). I already updated the files rgbcurves.zip and rgbcurves2.zip on my server, so you can immediatelly download the new version.

William Hohauser October 7th, 2010 08:26 PM

Quote:

Originally Posted by Dominik Seibold (Post 1576556)
Well, the installer isn't empty, but of course (I guess it's a trust issue) I can also give you the raw fxplug File/Folder:
http://www.dominik.ws/rgbcurves2.zip

It's not that, but it didn't install after running it. But thanks for the direct plug-in. I'm going to try it now.

William Hohauser October 7th, 2010 08:53 PM

Not to be a nuisance but the plug-in unzipped as a folder.

Dominik Seibold October 7th, 2010 10:26 PM

Quote:

Originally Posted by William Hohauser (Post 1576680)
Not to be a nuisance but the plug-in unzipped as a folder.

Yes, you have to copy that folder to /Library/Plug-Ins/FxPlug (or ~/Library/Plug-Ins/FxPlug). But I guess the folder is already there, because you already executed the installer package. I'm not sure why my plugin isn't shown in your plugin-list. Which version of Final Cut do you have?

Simon Denny October 8th, 2010 02:30 AM

Hi Dominik,

Where can I find the updated cures version for downloading?

Cheers

Anthony J. Howe October 8th, 2010 05:28 AM

I have been testing this Dominik, and it works great, what a great time-saver and so easy to use.
Well done and thanks.


All times are GMT -6. The time now is 07:11 AM.

DV Info Net -- Real Names, Real People, Real Info!
1998-2024 The Digital Video Information Network