Grain, can I reduce it?

"Lunaray" wrote:

I’ve got some old slides that I scanned and everything about them is perfect except that the grain really shows, is there a way to lessen the grain without degrading the sharpness?

Thanks all,
Ray

I don’t deal with grain or noise to have more detailed trick to share, but I believe Photoshop CS2 (and probably CS3 as well) comes with some plug-ins to handle Noise, Freckle, Grain from scanned image etc..

I believe it may just add some BLUR to reduce the grain. The old trick I used years ago when I was still trying to repair some damaged, old low-rez image etc. by using multiple layers. You add BLUR to top layer then blend to the lower and similar.

"Lunaray" found these unused words:

I’ve got some old slides that I scanned and everything about them is perfect except that the grain really shows, is there a way to lessen the grain without degrading the sharpness?

Thanks all,
Ray

Perhaps Noise Ninja might reduce the grain enough to satisfy you.

Is the grain recorded on the slide or a result of your scan?

If you have done any sharpening of course you have sharpened the grain as well. Apply sharpening selectively and only sharpen the detail areas and avoid applying the sharpening filter to area of the image, such as the sky, where you do not need to sharpen.

Multi-sampling or over-sampling your scan can result in better, less noisy scans. Most scanner software designed to scan slides and negs have a setting for this. It takes allot longer to get your scan finished but it worth the wait.

If you still have noise/grain issues, There are plug-ins available to help… I use NIK’s Define. But still apply the filter selectively via layers so as not to loose detail in you image…

"Lunaray" wrote in message

I’ve got some old slides that I scanned and everything about them is perfect except that the grain really shows, is there a way to lessen the grain without degrading the sharpness?

Thanks all,
Ray

From: "Lunaray"

I’ve got some old slides that I scanned and everything about them is perfect except that the grain really shows, is there a way to lessen the grain without degrading the sharpness?

Hi Ray,

The answer is yes, you can reduce it. You can also retain image detail. Reading between the lines, my guess is that what you are seeing is not grain as such, but noise in the shadows. Slides, in particular, are prone to this, because consumer level scanners have trouble scanning the dense areas of slides. If you notice the problem especially with darker, underexposed slides, this is probably what you are seeing. Slides don’t really have a grain structure because the image is made up of dye deposits, not silver granules.

For general noise removal, there are at least two very good noise reduction plugins – Noise Ninja and NeatImage – that you may want to experiment with. Last time I checked, NeatImage (http://neatimage.com/) had a 100% functional stand alone version, and Noise Ninja (http://www.picturecode.com) probably offers something similar.

If you want to spend a an hour or two learning and experimenting you can get excellent results on your own, using a technique recently described by Dan Margulis in another forum. CS2 and CS3 have a noise reduction feature, called surface blur, which adds blur to flat areas (removing noise), and preserves edge detail. Dup your image to a new layer, apply surface blur, adjust the radius until you see the noise just go away, and the threshold until you just see edge detail preserved. Set the transparency down (to 75 percent or so) to eliminate the plastic look that surface blur is prone to.

Using a shadow mask (white for shadows) in conjunction with surface blur is an effective way to deal with nose in the shadows. One way to get a shadow mask is to dup the image, convert to CMYK, copy and paste the K channel to a layer mask (remember to alt click the layer mask after you create it), and invert it.

Margulis’s new method relies on a gamma calculation to redistibute color values out of the shadows, and does not require a mask. Type ctrl-shift-K access Color Settings, select Custom RGB as your RGB working space, set the gamma to 1.0, and save this as "RGB Gamma 1", adding it to the list of profiles available in Photoshop. Set your RGB working space back to normal (usually sRGB or Adobe RGB 1998), and convert your image to the RGB Gamma 1 space that you created. The result of this more numerical leverage in the shadows so that the results of surface blur will be more confined to the shadows.

If the above strikes you as a bit complex, you are not alone. At least now you know why NeatImage and Noise Ninja make their bucks, LOL. —
Mike Russell – www.curvemeister.com

Hi Ray,

The answer is yes, you can reduce it. You can also retain image detail. Reading between the lines, my guess is that what you are seeing is not grain as such, but noise in the shadows. Slides, in particular, are prone to this, because consumer level scanners have trouble scanning the dense areas of slides. If you notice the problem especially with darker, underexposed slides, this is probably what you are seeing. Slides don’t really have a grain structure because the image is made up of dye deposits, not silver granules.

Thanks Mike for your considerate and detailed reply to my post!

Maybe it is a bad scan, I haven’t examined the original slide under high magnification so I’m not sure, but it sure looks like actual emulsion grain to me. You can see the image I’m talking about here:
www.southforkmtnmusic.com/tmp/CP355-9.tif but be warned, it’s a big file (raw scan at max resolution), and it will probably take awhile to open depending on your connection speed.

Thanks again for your help.

Ray

Lunaray wrote:

I’ve got some old slides that I scanned and everything about them is perfect except that the grain really shows, is there a way to lessen the grain without degrading the sharpness?

Thanks all,
Ray

I seem to remember reading once about a package called Noise Ninja. That might be worth giving a try.

"Lunaray" wrote in message
[re noise in scanned image]

Thanks Mike for your considerate and detailed reply to my post!
Maybe it is a bad scan, I haven’t examined the original slide under high magnification so I’m not sure, but it sure looks like actual emulsion grain to me. You can see the image I’m talking about here: www.southforkmtnmusic.com/tmp/CP355-9.tif but be warned, it’s a big file (raw scan at max resolution), and it will probably take awhile to open depending on your connection speed.

Hi Ray,

You’d think I would have learned by now not to jump the gun, but I love shooting from the hip, LOL. I got home after being on the road and downloaded your image. Contrary to my first guess, the noise is *not* mainly in the shadows, but the reverse. It’s more noticeable in the brighter areas.

I got an improvement by duping the layer, running surface blur Radius 8 Threshold 16, and then dropping the transparency of the new layer to about 50 percent. The main defect was a sort of ragged look in areas of greater contrast, such as the edges of the mountain, presumably where the thresholding kicked in. These defects are probably small enough not to show on an 8×10 print.

Running the NeatImage standalone demo gave a better result – detail level was about the same, with less noise, and no ragged edges.. I suspect Noise Ninja, which is also highly regarded, would also be satisfactory, and if you plan to do many scans like this it might be worth the investment. —
Mike Russell – www.curvemeister.com

Lunaray wrote:

www.southforkmtnmusic.com/tmp/CP355-9.tif

That looks like it’s from the Asian Pacific Rim. Do I win a cookie?

Drew

"Drew" wrote in message

Lunaray wrote:

www.southforkmtnmusic.com/tmp/CP355-9.tif

That looks like it’s from the Asian Pacific Rim. Do I win a cookie?
Drew

Sorry, you lose, it’s of Mt. Hood in Oregon.

slide do have grain structure and i would say grain pattern from the silver grains just like color negative but its pattern is finer.

"Mike Russell" wrote in message

From: "Lunaray"

I’ve got some old slides that I scanned and everything about them is perfect except that the grain really shows, is there a way to lessen the grain without degrading the sharpness?

Hi Ray,

The answer is yes, you can reduce it. You can also retain image detail. Reading between the lines, my guess is that what you are seeing is not grain as such, but noise in the shadows. Slides, in particular, are prone to this, because consumer level scanners have trouble scanning the dense areas of slides. If you notice the problem especially with darker, underexposed slides, this is probably what you are seeing. Slides don’t really have a grain structure because the image is made up of dye deposits, not silver granules.

For general noise removal, there are at least two very good noise reduction plugins – Noise Ninja and NeatImage – that you may want to experiment with. Last time I checked, NeatImage (http://neatimage.com/) had a 100% functional stand alone version, and Noise Ninja (http://www.picturecode.com) probably offers something similar.
If you want to spend a an hour or two learning and experimenting you can get excellent results on your own, using a technique recently described by Dan Margulis in another forum. CS2 and CS3 have a noise reduction feature, called surface blur, which adds blur to flat areas (removing noise), and preserves edge detail. Dup your image to a new layer, apply surface blur, adjust the radius until you see the noise just go away, and the threshold until you just see edge detail preserved. Set the transparency down (to 75 percent or so) to eliminate the plastic look that surface blur is prone to.

Using a shadow mask (white for shadows) in conjunction with surface blur is an effective way to deal with nose in the shadows. One way to get a shadow mask is to dup the image, convert to CMYK, copy and paste the K channel to a layer mask (remember to alt click the layer mask after you create it), and invert it.

Margulis’s new method relies on a gamma calculation to redistibute color values out of the shadows, and does not require a mask. Type ctrl-shift-K access Color Settings, select Custom RGB as your RGB working space, set the gamma to 1.0, and save this as "RGB Gamma 1", adding it to the list of profiles available in Photoshop. Set your RGB working space back to normal (usually sRGB or Adobe RGB 1998), and convert your image to the RGB Gamma 1 space that you created. The result of this more numerical leverage in the shadows so that the results of surface blur will be more confined to the shadows.

If the above strikes you as a bit complex, you are not alone. At least now you know why NeatImage and Noise Ninja make their bucks, LOL. —
Mike Russell – www.curvemeister.com