Loss of saturation after Topaz Denoise 6

[cortlander]

Recently I started scanning some very old slides, memories from long ago, with an Epson 850 and Silverfast 8 AI Studio, inspired by Mark Segal's excellent write ups. After scanning, I brought the TIFF files into capture one 10, and as a first step opened them into Topaz photoFxLab and from there to Topaz DeNoise 6. I used a light setting of about 0.10 in Luma, and it did a decent job of cleaning up the noise. The colors at this point looked fine too. However, when I saved them back to Capture One, the file from DeNoise seemed to have lost quite a bit of saturation.

I am attaching downscaled files (original scan was about 170 MB). I am new to Topaz DeNoise and any suggestions would be much appreciated.

Best,

[kirkt]

The before and after you posted looks a lot like an image that starts in a larger color space (like ProPhoto) and somewhere along the line gets *assigned* a smaller color space (like sRGB).  I wonder if there is something going on in your workflow that is altering the color interpretation.  If I just grab your sRGB "before" image, open it in PS and run it through DeNoise (via the PS plug in), there is no difference in color - but that may not be representative of the treatment of your original image file.

Can you post a link to download a reduced res version of the original scan?  What color profile tag is embedded in it?

kirk

[Bart_van_der_Wolf]

Recently I started scanning some very old slides, memories from long ago, with an Epson 850 and Silverfast 8 AI Studio, inspired by Mark Segal's excellent write ups. After scanning, I brought the TIFF files into capture one 10, and as a first step opened them into Topaz photoFxLab and from there to Topaz DeNoise 6. I used a light setting of about 0.10 in Luma, and it did a decent job of cleaning up the noise. The colors at this point looked fine too. However, when I saved them back to Capture One, the file from DeNoise seemed to have lost quite a bit of saturation.

Hi,

Just to make the analysis easier, you can skip the step through photoFXlab, because Denoise 6 is not only a plugin but also a stand-alone application. The fewer steps/applications involved, the easier it is to find out where the profiling gets it wrong, which is what I also expect to be the cause.

Cheers,
Bart

[cortlander]

Thanks Bart, that makes sense. I opened the file with De Noise and as you expected, it behaved as it should, and is definitely not where my problem is. The problem occurs in saving from photoFxLab. Fx to DeNoise and back is fine too, but Fx to saving it to the file system directly is where something gets messed up.

Hi,

Just to make the analysis easier, you can skip the step through photoFXlab, because Denoise 6 is not only a plugin but also a stand-alone application. The fewer steps/applications involved, the easier it is to find out where the profiling gets it wrong, which is what I also expect to be the cause.

Cheers,
Bart

[cortlander]

Thanks Kirk - you are right.  Somewhere my color space is getting screwed up. Topaz PhotoFx to DeNoise and back is fine, but Fx to saving it to the file system is where something gets messed up. The 'Save As..' option gives a choice of 4 color spaces - saving as sRGB is closest to the original, and then I see progressively less color going to Adobe RGB and Prophoto RGB.

I generally set my color space to prophoto RGB both as output from Silverfast scanner software, and in CO. Unfortunately, my smug mug site will not let me upload tiff file. I resized the original prophoto.tif and have attached it here, along with the prophoto.tif saved through photoFxLab without any further processing. There is quite a difference. I don't get it.

Best,
cortlander

PS - sorry, the attachments did not go through, a bit large. I need to figure a better way to show this.

The before and after you posted looks a lot like an image that starts in a larger color space (like ProPhoto) and somewhere along the line gets *assigned* a smaller color space (like sRGB).  I wonder if there is something going on in your workflow that is altering the color interpretation.  If I just grab your sRGB "before" image, open it in PS and run it through DeNoise (via the PS plug in), there is no difference in color - but that may not be representative of the treatment of your original image file.

Can you post a link to download a reduced res version of the original scan?  What color profile tag is embedded in it?

kirk

[cortlander]

Well...whatever the demons that had been lurking in my environment seemed to have disappeared. Checking the files in photoshop, the original appear correctly as "Prophoto RGB(16bpc)" through the Document Profile as one would expect. After loading the file into PhotoFxLab and saving it, and bringing it back into photoshop, it is labeled "Untagged RGB(16bpc)" but looks very similar to the original. The same was also true with a PrinterEvaluationImage_V002_Prophoto file.

Best,