Tool to fake a bayer filter? at DVinfo.net

Thomas Smet · July 13th, 2006, 06:52 PM

Anybody know which tool I could use to take an RGB rendered image from a 3D program and perform a bayer filter on it to try and match the footage from a camera that uses a bayer filter?

Nick Jushchyshyn · July 13th, 2006, 11:05 PM

Not sure that a Bayer filter effect would be a big help really.
The artifacts from DV compression, focus, CCD noise and lighting/dynamic range will generally outweigh the more subtle effects of a Bayer setup.

What software are you rendering from? What are you using to comp?
Can you post a still-frame of the "raw" CG render over the background video for review?

Glenn Chan · July 13th, 2006, 11:07 PM

Are you trying to match the Bayer artifacts specifically, or the overall look in general??? For the overall look, the Bayer artifacts probably only contribute a miniscule difference between the looks.

If you really wanted, a theoretical plug-in/program could convert your rendered image to a RAW format which you'd then de-mosaic. But this may not actually be what you're looking for (and I don't know of any such program).

Thomas Smet · July 14th, 2006, 08:09 PM

I guess I am trying to figure out a way to match 3D with video shot with a bayer filter. When a bayer filter is used pixels are interpolated. I realize there are other factors that hurt the image quality and detail and I would like to deal with those as well. I'm using Shake and/or Combustion. The 3D is from 3D Studio Max 7. The problem I see with rendered images is that they just never take on the same look as the video they are composited with. A RGB rendered image with have every single pixel accurate. A bayer filter image will not. I'm hoping by dumbing down the perfect images they will blend a little bit better. If we cannot get perfect RGB images from cameras then the next best thing would be to make computer graphics look like it came from the same camera. I realize this may be overkill but I figured it was something I would like to experiment with to see how it turned out.

What program can I use to do a de-mosaic on an image?

Nick Jushchyshyn · July 15th, 2006, 07:47 AM

Quote:

Originally Posted by Thomas Smet

I guess I am trying to figure out a way to match 3D with video shot with a bayer filter.

In your Shake comp, I'd probably start by using a combination of the DeFocus, Pixelize and Grain filters (in the Filter Tab).

You may also consider the Sharpen node, since most consumer cameras apply their own sharpening filter to the CCD image before recording to tape and CG generally lacks the artifacts that result from this extra sharpening step (which should be applied after the blur).

July 13th, 2006, 06:52 PM	#1
Thomas Smet Trustee Join Date: Mar 2004 Location: Milwaukee, WI Posts: 1,719	Tool to fake a bayer filter? Anybody know which tool I could use to take an RGB rendered image from a 3D program and perform a bayer filter on it to try and match the footage from a camera that uses a bayer filter?

July 13th, 2006, 11:05 PM	#2
Nick Jushchyshyn Major Player Join Date: Feb 2004 Location: Philadelphia, PA, USA Posts: 548	Not sure that a Bayer filter effect would be a big help really. The artifacts from DV compression, focus, CCD noise and lighting/dynamic range will generally outweigh the more subtle effects of a Bayer setup. What software are you rendering from? What are you using to comp? Can you post a still-frame of the "raw" CG render over the background video for review? __________________ Nick Jushchyshyn Matchmoving, Compositing, TD imdb

July 13th, 2006, 11:07 PM	#3
Glenn Chan Inner Circle Join Date: Jun 2003 Location: Toronto, Canada Posts: 4,750	Are you trying to match the Bayer artifacts specifically, or the overall look in general??? For the overall look, the Bayer artifacts probably only contribute a miniscule difference between the looks. If you really wanted, a theoretical plug-in/program could convert your rendered image to a RAW format which you'd then de-mosaic. But this may not actually be what you're looking for (and I don't know of any such program).

July 14th, 2006, 08:09 PM	#4
Thomas Smet Trustee Join Date: Mar 2004 Location: Milwaukee, WI Posts: 1,719	I guess I am trying to figure out a way to match 3D with video shot with a bayer filter. When a bayer filter is used pixels are interpolated. I realize there are other factors that hurt the image quality and detail and I would like to deal with those as well. I'm using Shake and/or Combustion. The 3D is from 3D Studio Max 7. The problem I see with rendered images is that they just never take on the same look as the video they are composited with. A RGB rendered image with have every single pixel accurate. A bayer filter image will not. I'm hoping by dumbing down the perfect images they will blend a little bit better. If we cannot get perfect RGB images from cameras then the next best thing would be to make computer graphics look like it came from the same camera. I realize this may be overkill but I figured it was something I would like to experiment with to see how it turned out. What program can I use to do a de-mosaic on an image?