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Grain Reduction

Mon Sep 18, 2000 10:35 pm

Howdy everyone!
I would like to know is there anything possible to do to reduce the grain of a photo after having scanned it, preferably with Paint Shop Pro or Photoshop?

Nicolas Bourbillon
 
ckw
Posts: 4586
Joined: Fri Aug 27, 2010 12:26 am

RE: Grain Reduction

Tue Sep 19, 2000 1:40 am

Probably not without a trade-off in other respects - sometimes smoothing helps (particularly in sky areas) but this will reduce the apparent sharpeness of other areas.

The question is why are you getting problem grain in the first place? Even 400 ASA (with decent film!) - if properly exposed should not produce offensive grain. Grain is usually only a problem if the image is underexposed.

If you have an even slightly underexpsoed image and you try and compensate during scanning, you will increase the problem. Instead, try making the initial scan true to the original (ie. slightly underexposed) and then adjusting the scanned image using "tone curve" in photoshop.

Another trick which might work - scan the image at a high resolution (much higher than required) and then in photoshop resample the image down to the required size, followed by application of unsharp mask.

Cheers,

Colin
Colin K. Work, Pixstel
 
USAir_757
Posts: 949
Joined: Wed Jun 14, 2000 12:30 am

RE: Grain Reduction

Tue Sep 19, 2000 6:59 am

Hi

Paint Shop Pro 7 beta has a grain reduction feature.


Click for large version
Click here for full size photo!

Photo © C. Wassell




Regards
C. Wassell
-Cullen Wassell @ MLI | Pentax K5 + DA18-55WR + Sigma 70-300 DL Macro Super
 
FastGlass
Posts: 273
Joined: Thu Jan 10, 2002 1:01 pm

RE: Grain Reduction

Tue Sep 19, 2000 2:37 pm

If you have grain, I hope it is AFTER you have altered the scan (as in sharpening). IF you have grain after a RAW scan, you will have a tough time softening the scan without losing sharp details.
 
TomH
Posts: 950
Joined: Thu May 27, 1999 4:13 am

RE: Grain Reduction

Thu Sep 28, 2000 10:29 am

A few of my older B&W negs had objectionable grain, most noticeable in the sky portion of the photo. What works for me in reducing the grain is to manually draw a mask around the sky. I do this by zooming in and meticulously tracing around the subject aircraft and any other objects so they aren't affected by the next step. Then I apply a softening blur to the masked area. Be sure to experiment so the softening doesn't smooth out desirable objects in the sky-like clouds. Do this after your final sharpening/unsharpening.

You shouldn't have to do this often, so if you are constantly plagued by graininess, you need to find the root cause. Good luck.
 
chris28_17
Posts: 1372
Joined: Sun Jul 09, 2000 4:26 am

RE: Grain Reduction

Thu Sep 28, 2000 1:24 pm

hey tom! thats exactly how i fixed this picture... sorry i havent learned to actually post the picture but here is a link, check it out...

http://airliners.net/open.file?id=110503



CHRIS
 
TomH
Posts: 950
Joined: Thu May 27, 1999 4:13 am

RE: Grain Reduction

Fri Sep 29, 2000 7:51 am

Chris,
Dramatic sihouette effect you got there Chris. I sure don't see any grain anywhere, either. Nice job-almost as good as B&W !!!!!!

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