Downsampling noisy images

[DafO]

I photograph gigs/concerts with a D800 for a press agency and have been told to upload jpegs < 5Mb. With low light and pushing ISO 5000/6400 the images can get noisy.

With super noisy images I use Nik Collection Dfine, but it is relatively quite slow so generally avoid it if possible as I need a quick workflow.

To reduce my jpeg sizes I initially save at a lower jpeg quality, but after that I downsample / downscale.

Have also read that downsampling can help reduce noise.




I'm wondering what is the best resampling method to use in Photoshop (CS6) for:
- Reducing noise
- Keeping edge sharpness

Have read various sites, but none have a clear decision on:
- Bicubic
- Bicubic Automatic
- Bicubic Smoother
- Bicubic Sharpener

I guess my needs of reducing noise but keeping sharpness are at odds.


Also for the option of:
File -> Automate -> Fit Image

(which I've been using in cations)
Does anybody know which resampling method this uses ?

 

[sankos]

Maybe this will help. In case of CS6, I'd choose the plain Bicubic. Change the jpeg quality as the last stage, after noise reduction/downsampling/output sharpening. I use Noiseware -- it's faster than Topaz DeNoise and Nik Dfine.

--
Marcin

 

[DafO]

Done some testing to check what does what in terms of the automatic stuff, analysed the resulting file sizes

Image size with resampling:
Bicubic = 123Kb
Bicubic Automatic = 138Kb
Bicubic Sharper = 138Kb
Bicubic Smoother = 118Kb
Automate:
Fit Image, then set DPI without resampling = 123Kb

So decided/assumed:


When reducing.....
Bicubic Automatic = Bicubic Sharper
Automate-Fit Image = Bicubic


The Bicubic Sharper - is sharper - shocker but alas it sharpens the noise too.
I think plain "Bicubic" is closer to the smoother than the sharper version.


Bicubic


Bicubic Smoother


Bicubic Sharper

if you flip between them in a browser sharper/smoother differences are move obvious.