Forum: Photoshop


Subject: Noise in Picture.

goido opened this issue on Dec 05, 2000 ยท 10 posts


goido posted Tue, 05 December 2000 at 10:08 AM

Everytime I scan a print into Photoshop I get noise in the shadow areas. Right now I can not afford a $1500 dls film scanner so I have to use a print and scan it on my flatbed. What I do is scan it at 300 dpi and then resample it to 150, I also sometimes convert the file to Lab and then aply the median filter to the most ofending channel and then I sharpen the lightness channel. I hope there is a better way to get rid of the scanner noise in a file in photoshop. Any suggestions?? Andres.


Jim Burton posted Tue, 05 December 2000 at 4:19 PM

goido- Best way is to not have any noise! You might try playing around with the contrast and brightness setting on the scanner to get more range in the darks, you can always reverse the adjustments in Photoshop. Part of the problem is most (all?) scanners use a lineal gamma curve, which makes the darks too close togeather, so they tend to block up. If you've got a old 24 bit scanner you might want to think about getting a new 32 or 36 bit scanner, the main advantage of the extra bits is more dark detail.


goido posted Thu, 07 December 2000 at 5:50 PM

Well right know I don't want to spend on a new scanner, I rather save for a film scanner. I was given this tip. Ric Kelly - 11:45pm Dec 6, 2000 Pacific (#1 of 3) One thing you can try is make the image RGB. Duplicate the image on a new layer so you have two copies of the photo in teo layers. on the top layer, apply the median filter and guassian blur to soften the image quite a bit. Set the blending mode to color. You can see how much it improves the image by looking at the individual channels and making the top layer hidden and visible. I find this not only cleans up noise, but also adds detail to the blue channel


apesnater posted Tue, 19 December 2000 at 2:56 AM

Did you try using a raster when scanning. You can buy them in a copy-shop. about $5. A very cheap solution and you nice and crisp scans.


apesnater posted Tue, 19 December 2000 at 2:57 AM

duhh, you GET...........;-)


Jim Burton posted Wed, 20 December 2000 at 1:02 PM

Hi apesnater!- Never hear of a raster, what is it?


apesnater posted Fri, 22 December 2000 at 3:17 AM

it's a film with a grid on it.


Jim Burton posted Sat, 23 December 2000 at 1:12 PM

Never heard of it, but I've only been working with scans since 1987 or so ;) I fail to see how any screen between the scanner and the scan can improve the quality, if the pitch didn't exactly match the scanner resolution you would get a moire pattern, just like when you scan a printet halftone image.


goido posted Sat, 23 December 2000 at 3:06 PM

I just downloaded a copy od Vuescan and guess what? No artifacts on my cheese HP 4p scanner. Is only $40 and it was highly recommended at Adobe Forums.


apesnater posted Wed, 03 January 2001 at 7:43 AM

It's a technique I used when there were no scanners, only copymachines. it really works!!!!!!! Check you local copyshop.