max_neivandt1 Posted March 8, 2005 Share Posted March 8, 2005 Hello everyone, attached is a crop from a picture of some star trails scanned from Velvia (using an Epson 4870). The film was quite dense so I have boosted it a lot with curves and as a result a horizontal noise pattern of lines has become just visible. I hope you can see this in the attached picture. I think this pattern of lines is an artifact from the scanning that occurs when I try to get a picture from a dense slide. I would like to find a way to get rid of it. What I would like to do is try to copy a vertical section of the picture, clone out the start trails etc so that I am left with just the structure of the noise lines, blur it a bit, then invert it and overlay it on the main picture as a sort of mask to cancel out the underlying pattern of lines. I have been trying to do this but with no luck. I cant figure out the right kind of overlay to apply, or the right opacity etc. Please Help!Max. Link to comment Share on other sites More sharing options...
sjmurray Posted March 8, 2005 Share Posted March 8, 2005 Max, I don't see the "horizontal noise pattern" in this jpg. Have you tried any of the noise reduction programs like Neat Image? I think you can download it for a trial period. Link to comment Share on other sites More sharing options...
max_neivandt1 Posted March 8, 2005 Author Share Posted March 8, 2005 The pattern I am talking about is a little hard to see. If you turn the brightness up it becomes more apparent. Also if you look at some of the star trails you see they are not consistent density along their length, and these inconsistencies extend through the width of the photo. I havent tried any of the noise removal program because the problem I have is more a 'structured' pattern, not a grain or random noise pattern. Link to comment Share on other sites More sharing options...
alexdi Posted March 8, 2005 Share Posted March 8, 2005 I question the calibration of your monitor. I have to drag the white point to that picture to below 170 before I see even a hint of pattern. That said, all three major noise reduction programs do an admirable job removing it. Neat Image offers a free demo fit for the purpose. DI Link to comment Share on other sites More sharing options...
jim_leonard Posted March 9, 2005 Share Posted March 9, 2005 A problem you're going to run into is that there are dozens of star trails right at the same level as the noise. This will seriously impair any noise removal. Link to comment Share on other sites More sharing options...
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