View Full Version : Need help getting rid of noise/graininess redmaccat 07-12-2004, 08:16 PM Hello everyone.
I'm new to the retouching game and in need of some help. I've scaned some prints that were originally about 3x2 and enlarging them. With the enlargement I notice a lot of what looks like noise/pixelation/graininess. I've removed all the dust specs and such and now would just like to smooth it out. I've seen some tips for this using blur and noise filters in PS, but I can't seem to get it quite right. Any filter I apply seem to make it lose too much detail. I would really appreciate any help. I'm using PS7 and I've attached a small image of one I'm having the most trouble with.
Thanks much in advance. freelancer 07-12-2004, 10:05 PM Hi redmaccat,
What dpi did you scan at? You'll get the best results, particularly if you intend to retouch a photo, if you scan at at least 300 dpi at the intended printed size.
A 3x2 photo scanned at 300dpi will print a 3x2.
A 3x2 photo scanned at 600dpi will print a 6x4.
Add retouching to the equation and increased resolution might be an assist in getting the best results.
I took a look at your attachment and it does have a lot of artifacts which, if given the increased resolution, could be managed to provide a better result. 1STLITE 07-12-2004, 11:33 PM thank you thank you thank you, freelancer
I have struggled with that question of what to acan at. You have just given me the simplest and best explanation. THANK YOU!!!!!! Except (life is never too simple) that if you have an older scanner it may not "really" scan at the higher resolutions. My elderly flatbed scanner, for example, only really scans up to 300dpi. You can select higher dpi settings, but all that does is make the scanner software scale the picture up the same way (but with less control) as Photoshop would. So check your scanner documentation to see if that's the case for you. Vikki 07-13-2004, 05:14 AM To answer your question about Noise, try using Neat Image. It's a free download, and can do wonders on these grainy images.
I just wanted to add a couple of other tips:
It's always best to scan in full color. Many times you can reduce the noise by selecting one good channel and converting that to grayscale.
Looking at your image, it looks (and I may be wrong) like you'e used Dust & Scratches, or some other type of global filter on the image. If so, use these sparingly as they may help clean up some noise and dirt, but they have a tendency to lose the detail and soften the image. at the scanning set correctly the white point and the black point to get max. of details
i donno what kind of scanner u've but i think it knows kind of descreening>set it
do not sharpening at scanning
set the scanner maximum resolution
try to rotate the orig. in the scanner> try diff. degrees
set the scale 2x than u need at last
use softlight and hardlight layers to sharpening not filters even usm
if pict. lose details change mode to Lab> split chanels> take lightness file> copy background mode: multiply> adjust it by levels> merge layers> merge channels
good luck One way you can increase the size of your picture with minimal loss of detail is to increase it's size in 10% increments. You could also try using Noise: Median: Set to 1 or 2.
Cheers
Dave redmaccat 07-13-2004, 09:09 AM ummm...to answer all your questions:
I have an HP SJ 5370C.
I tried different settings, but wound up with telling the scanner to scan it at 5x7 size at 300 dpi at medium sharpening...oh and I deselected the "descreen" option. It is a fairly severe crop. The original has quite a bit of landscape in it (see attached).
I scanned it as color and used the calculations tool in PS7 to turn it greyscale.
No major filters were applied, I used the healing brush to remove the dust specks.
Looked at Neat Image, but it's for Windows only. Anyone know a version of Neat Image or something like it for Mac OS X? I'm willing to try just about anything at this point so keep those suggestions coming. :pleased:
Thanks. freelancer 07-13-2004, 02:44 PM Hi redmaccat,
If I understand this problem correctly, I think you still need to scan higher.
If the picture you've posted is the orginal full size, it measures 4.167" x 2.958", but the area that you want to crop out is approx. .611" x .847".
The cropped area is the area to base your size and dpi. The measurement of your original posted picture is 3.972" x 5.556".
The cropped area should be scanned at a minimum of 300dpi at 650% in order to get a file suitable for restoring and printing.
I'm not familiar with your scannner, but I wouldn't let the scanner do any sharpening for me. Scan in color and don't convert to greyscale until you have determined whether the color channels will assist you in your restoration. Save the file in .tif format to assure that compression isn't taking place.
Getting a good restoration on your photo is all in the pre-restoration, in my opinion.
Good luck :) redmaccat 07-13-2004, 05:22 PM Hi freelancer,
I'm sorry, I didn't mean to imply what I posted was the actual size of the scanned image. I have riduculusly slow dialup so anything I post at this point has to be pretty small. The actual size of the original (with landscape) scanned image is 8455x5998 pixels, giving me a 28x20 inch print at 300dpi. If I do a 7x5, it sets the dpi at about 1207. I told my scanner to scan to PS and in PS I saved it as a PS file instead of tiff or jpg. I didn't think a PS file would be compressed at all.
I have also scanned with no sharpening from the scanner and the result is the same. Maybe it's time for a new scanner? :idea:
Thanks for your help. freelancer 07-13-2004, 05:44 PM Oops, sorry! :)
You have a large file to work with, then you can start cleaning it up.
I did a quickie test with the cropped version you posted, First cleaned with neat image, then did levels and contrast, finally a high pass sharpen.
I think my test shows that with your proper scan you can get much better results.
PS: look at the individual channels, you might find that one is much cleaner than the others and can copy it and use it to start the restoration. redmaccat 07-14-2004, 06:00 AM Wow...there is hope! I think I'll be searching for a Mac version of Neat Image. Thanks for all your help. the Mac equivilant of Neat Image it NOISE NINJA
you can check it out here.
http://www.picturecode.com/
I've downloaded it but I've not yet taken the time to learn much about it.
BTW! it's nice to see another Mac user! I love my Mac! :pleased: redmaccat 07-15-2004, 12:59 AM That's great news! Thanks!
I had just been reading a review about Noise Ninja, but the Mac version wasn't out when the person reviewed it. This person really liked Noise Ninja out of a dozen other noise filters. I'll try it and let you know if it works for me...there goes my weekend! :grin: |