Coring at DVinfo.net

Shekar Dattatri · February 13th, 2005, 07:45 PM

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

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

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

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.

February 13th, 2005, 07:45 PM	#1
Shekar Dattatri New Boot Join Date: Feb 2005 Location: Chennai, India Posts: 24	Coring I haven't been able to figure out what exactly the 'coring' setting does. Would really appreciate some clarification. Thanks!

February 13th, 2005, 08:49 PM	#2
Chris Hurd Obstreperous Rex Join Date: Jan 2001 Location: San Marcos, TX Posts: 27,366 Images: 513	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. __________________ CH Search DV Info Net \| 20 years of DVi \| ...Tuesday is Soylent Green Day!

February 13th, 2005, 08:57 PM	#3
Pete Bauer Wrangler Join Date: May 2003 Location: Eagle River, AK Posts: 4,100	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 __________________ Pete Bauer The most beautiful thing we can experience is the mysterious. It is the source of all true art and science. Albert Einstein Trying to solve a DV mystery? You may find the answer behind the SEARCH function ... or be able to join a discussion already in progress!

February 13th, 2005, 08:58 PM	#4
Shekar Dattatri New Boot Join Date: Feb 2005 Location: Chennai, India Posts: 24	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 Wildlife and Conservation Filmmaker XL-2, DSR - 11, Aaton Super 16mm, Bolex EL Super 16mm

February 13th, 2005, 09:00 PM	#5
Shekar Dattatri New Boot Join Date: Feb 2005 Location: Chennai, India Posts: 24	Coring Pete, many thanks, this is very helpful. __________________ Shekar Dattatri Wildlife and Conservation Filmmaker XL-2, DSR - 11, Aaton Super 16mm, Bolex EL Super 16mm

February 13th, 2005, 09:05 PM	#6
Pete Bauer Wrangler Join Date: May 2003 Location: Eagle River, AK Posts: 4,100	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! __________________ Pete Bauer The most beautiful thing we can experience is the mysterious. It is the source of all true art and science. Albert Einstein Trying to solve a DV mystery? You may find the answer behind the SEARCH function ... or be able to join a discussion already in progress!

February 14th, 2005, 02:25 PM	#7
A. J. deLange Major Player Join Date: Jun 2004 Location: McLean, VA United States Posts: 749	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.

February 14th, 2005, 07:41 PM	#8
John Sandel Major Player Join Date: Sep 2004 Location: stately Eldora Road Posts: 386	"[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.