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-   Canon XL and GL Series DV Camcorders (https://www.dvinfo.net/forum/canon-xl-gl-series-dv-camcorders/)
-   -   Coring (https://www.dvinfo.net/forum/canon-xl-gl-series-dv-camcorders/39405-coring.html)

Shekar Dattatri February 13th, 2005 07:45 PM

Coring
 
I haven't been able to figure out what exactly the 'coring' setting does. Would really appreciate some clarification. Thanks!

Chris Hurd February 13th, 2005 08:49 PM

Basically it reduces video noise within areas of smooth textures and color gradations, such as a blue sky or painted wall, things of that nature.

Pete Bauer February 13th, 2005 08:57 PM

The Canon web site has this description:

Coring (-6 to +6)
The Coring function on the XL2 is useful in helping to remove image "noise." Coring removes fine detail information that is not a major contributor to the picture detail but which adds noise to the image. You can adjust just how much detail information is removed - just enough coring to reduce picture noise, but not enough to hurt the detail in the image.

Here's the link if you want to read Canon's description of other features, as well:
http://consumer.usa.canon.com/ir/con...elid=10350#f11

Shekar Dattatri February 13th, 2005 08:58 PM

Coring
 
Thanks Chris! While shooting a test yesterday, I noticed that an expanse of even coloured wall which was in shadow had quite a bit of noise as compared to the rest of the picture. Was wondering what could be done about it. I'll play with the coring setting and see how much of that can be reduced. This forum is just amazing, thank you!

Shekar Dattatri February 13th, 2005 09:00 PM

Coring
 
Pete, many thanks, this is very helpful.

Pete Bauer February 13th, 2005 09:05 PM

Your very welcome...and your comment about the even colored wall leads right into the artifacting post of yours that I just also responded to. That comment about the wall fits right in with an old thread that talked about noise.

For those who want to follow the more general discussion about artifacting of fine detail in your other thread, here's the link to that thread (and it has a link to the old thread):

http://www.dvinfo.net/conf/showthrea...threadid=39404

And anyone who really has a deep understanding of "coring" please do add to this thread!

A. J. deLange February 14th, 2005 02:25 PM

What coring does is separate the luminance into its high and low frequency components. The high frequency part is then run through a non linear transfer function such that small values, i.e. all values with magnitude (the high frequency component is bipolar even though luminance itself isn't) less than a threshold setting map to zero while values outside the threshold limits are passed straight through. The processed high frequency signal is then recombined with the low frequency part. The good news is that noise (which tends to be high frequency) is reduced on surfaces of approximately constant brightness. The bad news is that texture can be suppressed as well (coring smooths surfaces). I've never used it but have seen comments to the effect that use of coring to excess makes skin look like plastic.

John Sandel February 14th, 2005 07:41 PM

"[C]oring to excess makes skin look like plastic"
 
Which suggests some interesting creative possibilities ...

One of the things I love about the XL2 is how much, in a $3900 camera, I can deform the image for dramatic effect.

Not much good in wedding videography ('less she's a Stepford wife), but in dramatic work, this camera is an astounding tool for the dough.


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