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Old 23rd April 2012, 22:51   #38  |  Link
AMSS0815
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Join Date: Aug 2006
Posts: 29
Quote:
Originally Posted by shark000X View Post
Quote:
Originally Posted by AMSS0815
...a common structuring tensor from gradients of red/green/blue color planes. This tensor is a convex combination of the three tensors of each plane, with coefficients taken from some well known RGB-->YUV conversion matrix. AnalyzeLogo has to compute a common alpha channel from each color plane's alpha channel, this is also a convex combination, and the coefficients can be controlled by the *Weight parameters.
Aha. It may be the reason why we need to make PC.601 before analyzing a clip, I presume the three-spined tensor is calculated according to the following matrix resulting in some restrictions:
[.....]
No. I was wrong about the RGB<-->YUV conversion matrix. It is never directly used in my plug in. If InpaintLogo is applied to a RGB clip, the convex combination is simply the average of all 3 (or 4 for RGBA) channels. For YUV clips, the ChromaWeight parameter controls the coefficients. Coefficients for AnalyzeLogo's common alpha mask value are controlled by the estimated alpha values of each channel and a subsampling factor. There is also no RGB<-->YUV matrix involved here. (I learned that by reading my own docs).
Quote:
Now it seems the movie is mainly out of gamut (Photoshop>> Select / Range / Out of Gamut). When certain colors cannot be expressed within a particular color model, those colors are said to be out of gamut. As I think, the out of gamut colors may lead the AnalizeLogo to a wrong color estimation and big mistakes when creating the color map.
This is out of my expertise. If this means that the color values of your video were once rescaled and clipped (at least in audio processing this is called clipping, if they exceed the highest possible value), then yes, this is a kind of distortion that would violate AnalyzeLogo's assumptions about the logo and hence create a broken mask.
Quote:
I'm going to post the results for other users here, if you don't mind, to help avoid some bothering questions in future.
Of course. I don't see myself as the owner of this thread anyway.
-- AMSS0815
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