PDA

View Full Version : Reduce Noise or Despeckle?


waha
June 28th, 2011, 10:37 PM
Who can tell me the difference between "despeckle" and "reduce noise?"

I can clearly see the effect of noise reduction, but "despeckle seems to do nothing at all, even if I apply it five times in a row.

"Reduce noise" lets me control the strength etc., but "despeckle" seems to offer no controls whatever.

What am I doing wrong,
and
what would "despeckle" do that's different from "reduce noise?"

With thanks,
waha

David Penrod
June 28th, 2011, 11:48 PM
I believe despedkle is used to remove spots that may show up as white spots on a scanned Photo.

David

frank abramonte
June 28th, 2011, 11:54 PM
waha, a search of "difference between "despeckle" and "reduce noise" brings up a number of links that you may wish to browse.

http://search.yahoo.com/search;_ylt=ApWjVrjxb2vmXlqwAsPcOe2bvZx4?p=differe nce+between+%22despeckle%22+and+%22reduce+noise&toggle=1&cop=mss&ei=UTF-8&fr=yfp-t-701

Diana
June 29th, 2011, 12:01 AM
Hi Waha,

According to Adobe: The Despeckle filter is useful for dealing with mild-to-moderate luminance noise (as opposed to color noise).

From the Help file:

The Despeckle filter detects the edges in a layer (areas where significant color changes occur) and blurs all of the selection except those edges. This blurring removes noise while preserving detail. You can use this filter to remove banding or visual noise that often appears in scans of magazines or other printed materials.

The Reduce Noise filter reduces luminous noise and color noise, such as the noise introduced by photographing with insufficient light. Select the Remove JPEG Artifacts option to remove the blocky artifacts and halos that are caused by saving an image at a low JPEG quality setting.

Not much help, is it? I've found these filters aren't real effective. There are 3rd party plug-ins for Elements available that do a much better job. I use Imagenomic Noiseware Professional.

I haven't used these, but here are some free noise-reduction plug-ins:
http://www.softwhile.com/product_dn.html
http://www.colormancer.ca/free/download-filters/download.htm
http://www.digiretus.com/tippek/cikkiro.php?SORSZAM=222 (scroll down)

Diana