[Seriphu]

Hey Guys, recently I have been messing with some green screen footage and I notice a bit of noise in the blue channel. Is itnormal for HD footage to have this? Im still very new to keying and im learning what to expect when creating procedural mattes. If this is not normal of the footage is there a universal fix that is used in the industry to repair it?

Thanks

[Rayc]

hey seriphu, video has the most noise in the blue channel just like film has the most grain in the blue channel. You can try to apply a little blur in the b channel to soften those noise a bit for a better key.

[faridzadeh]

The blue channel will always be the noisiest channel. HD and Film. It's the way it is. If the grain is getting in the way of your key, then sometimes a soft blur on the blue channel might help. But every key is different.

[mrrafs]

yes blurring to denoise or degrain can be done is several advanced ways:

• Averaging frames
• Rank Order or Median Filter
• Adaptive spacial filtration
  • Wavelet
    • Furnace plugin
    • Neat-Image plugin (stills)
  • Other
    • Neat-Video plugin
• Temporal filtration
  • Furnace plugin
  • Neat-Video? plugin
• Edge Filter Blur (same as Saphire plugin)
• Chroma only Blur

see our MIAFX wiki for more nfo.

as well as this stuff on keying

good luck

[Gentle Fury]

Furnace is the best way to fix this, you can actually degrain per color channel, then bring back in the small and medium grain to look more natural.

It's $38 a day to rent!

[mrrafs]

-yes the grain tools in furnace are very good

the trick with furnace is to use the denoise and then the degrain for both temporal and adaptive filtration

[Seriphu]

Awesome, thanks a lot guys for clearing that up for me and the fixes. Blurring the blue channel worked great, still a slight bit of noise but it doesn't hurt anything in the key.