Adding preview windows for very low and ultra low frequency and increase their adjustable amount over +150?

suggest a way to improve Neat Image
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lansing
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Joined: Sat Apr 21, 2012 6:52 am

Adding preview windows for very low and ultra low frequency and increase their adjustable amount over +150?

Post by lansing »

I have found that the very low and ultra low frequency denoising very effective on cleaning out bleed through problem from scan, where things from the back of the page bleed to the front.

I would like to request the addition of preview windows for these two domains. Also the adjustable amount of +150 is not enough. On my scanned comic, I need over +150 on very low/ultra low frequency to remove the bleed through.

NITeam
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Re: Adding preview windows for very low and ultra low frequency and increase their adjustable amount over +150?

Post by NITeam »

Thank you for the suggestion regarding previews. We will consider possible options.

Regarding the adjustable noise levelif you need more it than +150%, then that may indicate that the noise profile is not accurate. It may be necessary to re-build the noise profile using a good sample of very low / ultra low frequency noise itself. This will more accurately measure that noise and you will not need to adjust it in the filter settings so much.

Vlad

lansing
Posts: 59
Joined: Sat Apr 21, 2012 6:52 am

Re: Adding preview windows for very low and ultra low frequency and increase their adjustable amount over +150?

Post by lansing »

Hi I tried building the auto profile using the the bleed through area, but it still doesn't covers it in the result.

Here's a sample image. Look at the soft curve line on the right.

I changed the image to grayscale in photoshop and feed it to Neat Image. In setting I maxed luminance noise reduction amount, mid/low/very low/ultra low frequency noise level, and turned off high frequency noise level. In the frequency windows I didn't see it but it was still there in the normal preview window, so it means it still lies somewhere in the very low and ultra low frequency domains.

NITeam
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Re: Adding preview windows for very low and ultra low frequency and increase their adjustable amount over +150?

Post by NITeam »

Please try these profile/preset to see if you get the same results with these as with your profile and filter settings.

Thank you,
Vlad

lansing
Posts: 59
Joined: Sat Apr 21, 2012 6:52 am

Re: Adding preview windows for very low and ultra low frequency and increase their adjustable amount over +150?

Post by lansing »

Hi your test profiles worked when running under RGB mode, with no soft bleed through left over. So is it the grayscale mode that I was using the cause of the problem?

If I'm to have my final output as grayscale, I should first run Neat Image->convert to grayscale instead of convert to grayscale->Neat Image?

NITeam
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Re: Adding preview windows for very low and ultra low frequency and increase their adjustable amount over +150?

Post by NITeam »

Probably that is not related to the RGB vs grayscale. I guess. Perhaps this is more about the profile and filter settings that I used. Notice that I increased the noise level in the filter settings. Also, I built the profile using a large area that included those bleeding lines. I think these two things together allowed to reduce those bleeding lines.

Vlad

lansing
Posts: 59
Joined: Sat Apr 21, 2012 6:52 am

Re: Adding preview windows for very low and ultra low frequency and increase their adjustable amount over +150?

Post by lansing »

Out of curiosity, I did a side by side comparison on the effect of denoising in rgb vs grayscale. I make the noise profiles both from sampling the curve line on the right of the image and then use the same noise filter setting from your zip. Then turned down the brightness of the preview window to the minimum to help easier spotting differences.

Image

From the comparison, looks like the RGB mode denoise the bleed through a little better.

NITeam
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Re: Adding preview windows for very low and ultra low frequency and increase their adjustable amount over +150?

Post by NITeam »

Perhaps a bit better in RGB but still quite noticeable.

It is not really noise after all, so it is not reduced just as well as the regular random noise.
As far as I can tell, tweaking the filter further will likely not give better results.

Vlad

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