Try it in LAB mode

general questions about Neat Image
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rnwhalley
Posts: 5
Joined: Wed Dec 15, 2004 2:04 pm

Try it in LAB mode

Post by rnwhalley »

:D After a year of using the software I think its the best on the market. BUT I think results can be improved by working with it in LAB mode.

Open the image in Photoshop and convert the Mode to LAB. Make any adjustments then apply the Surface Blur filter to the a and b channels in turn. Next apply Neat Image to the Lightness channel. Many times I have the profile quality report as 100% (something I never managed in RGB) and the results appear to be better; at least to my eyes.
TheMightyZog
Posts: 5
Joined: Mon Jul 10, 2006 2:39 pm

Post by TheMightyZog »

Hi,
I am interested in what you say and I too am becoming a fan of Lab mode, but what do you mean about Surface blur.
I also do not see how you judge what level of sharpening to use, when there is no preview of the final colour photo.
Is it not better to start with NeatImage, rather than finish with it?
Chris
rnwhalley
Posts: 5
Joined: Wed Dec 15, 2004 2:04 pm

Post by rnwhalley »

Hi Chris,

The surface blur I am referring to is done in Photoshop before using Neat Image. Try the following:

Convert your image to Lab and then open the Photoshop channels window. When you convert to Lab the colour (sorry about the spelling if you are not from England) noise is separated from the luminance noise. Colour information, including noise ends up in the a and b channels whilst the luminance noise is in Lightness (L) channel. You can now virtually eliminate the colour noise by applying the surface blur filter to the a and b channels. I like to start with a setting of 5 for Radius and 5 for Threshold. This should be enough to hide the noise but you can apply the filter again if it is a particularly noisy image.

I have found that it’s hard to over this last step and the a and b channels can take a lot of manipulation before the results deteriorate.

You can now select the L channel in your channels window and apply the Neat Image filter. When in Neat Image you will need to use the YCrCb working colour space to create your profile. When you then switch to the Noise Filter Settings page you will see that you are only working on the noise in the Y channel. I tend to have my “Noise Levels” set at High = -5%, Mid = -15% and Low = -30% whilst the Y value is set at +20%.

For the noise reduction amount I set values of High = +100%, Mid = +90%, Low = +90% and Y = +50%. I also apply a little sharpening to each of the channels in the order of 30% for High and 15% for Mid and Low.

I find the above settings give me a good starting point the I can refine without much loss of detail. Whilst there is no preview of the final colour image I find I can judge sharpness much better in the greyscale image i.e. Lightness channel as the colour isn’t a distraction. At the end of the sharpness is an illusion caused by the level of contrast between two adjacent areas of different tone. The greater the contrast the greater the sharpness. Working in Greyscale allows you to judge this better to my mind.

I do start with Neat Image but I have a Photoshop action that runs to achieve the above steps up to applying Neat Image. Once I have applied the filter I convert back to RGB to apply contrast, tone, brightness and any colour correction. Finally if my work is going to be printed I apply a suitable sharpening method (which might involve a further conversion to Lab.

The above might appear lengthy but I have tried Neat Image in RGB, on the individual channels in RGB and on the individual channels in CMYK (although you can’t work on the CMYK composite channel). In all case I believe I get superior results with this method.

Good luck and drop me a line if you have any other questions.

Robin
TheMightyZog
Posts: 5
Joined: Mon Jul 10, 2006 2:39 pm

Post by TheMightyZog »

Hi Robin,

That is very interesting - I have just been using NeatImage in Standard mode and am very happy with the results.

However I followed your instructions with this photo
Image
with your settings as I am not experienced enough to know how to change them.
When I compared the results, standard NeatImage gave a cleaner image.

I wonder if you could spare the time to tell me what the advanced values should be and then I could see if I should attempt to learn how to do it properly.

I actually used this image as an example of NeatImage's power on my website http://broadhurst-family.co.uk/ in the Software page.

Thanks
Chris[/img]
rnwhalley
Posts: 5
Joined: Wed Dec 15, 2004 2:04 pm

Post by rnwhalley »

Hi Chris,

I took a download of the image from this page to experiment. The first thing is that my original suggestion won't give a good result as it was for dealing with a low noise ISO 100 image (something I forgot all about because I tend to do most of my digital work at that setting).

As this image is ISO 400 and has quite a lot of noise I had to run the surface blur twice on each channel using the radius and threshold set to 5 both times.

I then worked on the Lightness channel with NeatImage. The profile I created gave a 76% Profile Quality. Ordinarily I would have created a high quality profile from another image and then applied it to this image. But as I don't have access to any other images from this camera I can't do that.

The settings I used are as follows:
Noise Levels
High = -5%, Med = -15% and Low = -30% and Y = +30%

Noise Reduction
High = 100%, Med = 40%, Low = 40% and Y = 50%

Sharpening
High = 80%, Med = 20% and Low = 0%

The reason for these settings is that most of the noise appeared to be in the High frequency area. The other point is that if you try to take a lot of noise from the low frequency area you can lose the texture of the stone. This is a problem that I first encountered when trying to remove noise from snow or ice – glaciers look terrible on the standard settings. Ultimately I have tried to leave a little of the luminance noise in place as I think it adds to the stone texture and removing this gave it a “plastic” appearance. Ultimately it might be a matter of personal taste.

The other point is that viewing the image in a browser the difference doesn't appear as extreme as when I have the two images side by side in Photoshop.

Having created an image using the above approach I ran a test using the default settings on the image in RGB. This gave a profile quality of 75%; not a great deal difference. The big difference for me was in the final image. The stone texture was gone (compare the top left of the two images) and also some of the carving detail had been lost. These differences could have been down to the less aggressive settings used, it’s hard to say.

Have a look at the test images below. The top one is using my settings and the lower one uses the default.

Interested to know your thoughts.

Regards
Robin

PS I tried to look at your web site but couldn’t get through the entry page??? If you get chance take a look at my site http://www.lenscraft.co.uk

Image

Image
RichardRegal
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Joined: Sun Dec 14, 2008 4:48 am

Post by RichardRegal »

How were you able to get it to work in LAB? Whenever I try to use the filter in LAB mode in Photoshop I get an error box with the message "Could not comple the Reduce Noise command because the filter module does not work with Lab Color images".

I am using version 6.0 of NeatImage.
rnwhalley
Posts: 5
Joined: Wed Dec 15, 2004 2:04 pm

Post by rnwhalley »

Once you have converted your image to LAB mode you need to go to the channels window and select just the Lightness channel. Whilst the software says that it won't work in LAB mode, it will work on inidividual channels. Trying to use it on the A or B channel is however pointless but I find good results using it on the Lightness channel.
RichardRegal
Posts: 5
Joined: Sun Dec 14, 2008 4:48 am

Post by RichardRegal »

Thanks. That is exactly what I needed, as I much prefer to work in LAB. I wonder if we should be setting the YCrCb Symm colour space when doing this.
rnwhalley
Posts: 5
Joined: Wed Dec 15, 2004 2:04 pm

Post by rnwhalley »

Good question and I hadn't given it much thought. I already use the YCrCb Symm colour space as my default. I seem to remember a version of the manual recommending it a few years back for the highest quality results. Must admit I haven't read the manual for quite some time and taking a quick look at it, it seems to have changed substantially from the copy I read.

Anyway, what's your thought process for using this colour space and are you experiencing better profile builds?
RichardRegal
Posts: 5
Joined: Sun Dec 14, 2008 4:48 am

Post by RichardRegal »

I’ve not had the chance to take any picures yet, and my profile photos are based on the old (black and white) target.

I am looking forward to trying though.
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