what is coring at DVinfo.net

Mo Zee · May 2nd, 2005, 07:06 AM

i've read all i can but cant get any real answer. any help appreciated.

Chris Hurd · May 2nd, 2005, 07:25 AM

I like the explanation that it's a poor man's noise reduction.

See http://www.videohelp.com/glossary?C#Coring

A. J. deLange · May 2nd, 2005, 09:58 AM

In coring the luminance is separated into its high and low frequency parts and the high frequency part processed so that any pixel with magnitude less than a threshold is set to 0. Any pixel with magnitude greater than the threshold is passed straight through. After this thresholding process the high and low frequency portions are recombined.

The result is noise reduction over areas of roughly constant luminance. If the threshold is set too high, however, the texture of objects is supressed, skin looks like plastic etc.

Mo Zee · May 2nd, 2005, 05:24 PM

thanks chris and a.j.

but when coring does touch a pixel, what happens to chroma?

is there an ideal setting? i'm finding ways to reduce noise on my xl-2. it has a lot of detail, but a lot of noise compared to my xl-1. thanks.

Greg Boston · May 2nd, 2005, 05:40 PM

Quote:

Originally Posted by A. J. deLange

<snip> If the threshold is set too high, however, the texture of objects is supressed, skin looks like plastic etc.

Well A. J., there must be a lot of 'high threshhold coring' taking place in Hollywood, judging from what I've seen. :-)

-gb-

A. J. deLange · May 2nd, 2005, 08:25 PM

AFAIK it is only done to the luma part of the signal because the high frequency components of the chroma components have already been removed i.e. they are much narrower bandwidth signals already.

Mo Zee · May 3rd, 2005, 01:31 AM

Quote:

Originally Posted by A. J. deLange

AFAIK it is only done to the luma part of the signal because the high frequency components of the chroma components have already been removed i.e. they are much narrower bandwidth signals already.

oh ok. i don't really understand video signals in terms of frequencies. only sound.

May 2nd, 2005, 07:06 AM	#1
Mo Zee Regular Crew Join Date: Jan 2002 Location: manila, philippines Posts: 102	what is coring i've read all i can but cant get any real answer. any help appreciated.

May 2nd, 2005, 07:25 AM	#2
Chris Hurd Obstreperous Rex Join Date: Jan 2001 Location: San Marcos, TX Posts: 27,368 Images: 513	I like the explanation that it's a poor man's noise reduction. See http://www.videohelp.com/glossary?C#Coring __________________ CH Search DV Info Net \| 20 years of DVi \| ...Tuesday is Soylent Green Day!

May 2nd, 2005, 09:58 AM	#3
A. J. deLange Major Player Join Date: Jun 2004 Location: McLean, VA United States Posts: 749	In coring the luminance is separated into its high and low frequency parts and the high frequency part processed so that any pixel with magnitude less than a threshold is set to 0. Any pixel with magnitude greater than the threshold is passed straight through. After this thresholding process the high and low frequency portions are recombined. The result is noise reduction over areas of roughly constant luminance. If the threshold is set too high, however, the texture of objects is supressed, skin looks like plastic etc.

May 2nd, 2005, 05:24 PM	#4
Mo Zee Regular Crew Join Date: Jan 2002 Location: manila, philippines Posts: 102	thanks chris and a.j. but when coring does touch a pixel, what happens to chroma? is there an ideal setting? i'm finding ways to reduce noise on my xl-2. it has a lot of detail, but a lot of noise compared to my xl-1. thanks.

May 2nd, 2005, 08:25 PM	#6
A. J. deLange Major Player Join Date: Jun 2004 Location: McLean, VA United States Posts: 749	AFAIK it is only done to the luma part of the signal because the high frequency components of the chroma components have already been removed i.e. they are much narrower bandwidth signals already.