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Author Topic: raw conversion with AI Gigapixel  (Read 282 times)

bwana

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raw conversion with AI Gigapixel
« on: July 10, 2019, 09:34:36 pm »

I noticed that AI gigapixel tends to exaggerate processing artifacts so I thought I would use it earlier in my workflow. I was surprised to see that it can open .NEF and .RAF files. I assume it's doing a raw conversion using libraw or some other open source demosaicising algorithm. Does anyone know?
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Bart_van_der_Wolf

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Re: raw conversion with AI Gigapixel
« Reply #1 on: July 11, 2019, 04:17:32 am »

I noticed that AI gigapixel tends to exaggerate processing artifacts so I thought I would use it earlier in my workflow. I was surprised to see that it can open .NEF and .RAF files. I assume it's doing a raw conversion using libraw or some other open source demosaicising algorithm. Does anyone know?

Hi,

I don't know the details, but yes most Topaz standalone applications  are able to process most common Raw fileformats. I'm not a big fan of using it myself, because you don't have any control over the Raw conversion process. It's 100%% automatic.

It may be better to avoid artifacts in the first place, so Gigapixel AI won't use and scale them to a larger and more visible size.

I tend to Raw convert and Edit files with Layers, which makes it possible and easy to switch on/off the steps that might be detrimental to visual quality when blown up larger. Should I run into artifacts that are caused by the Gigapixel AI models, I try to have the folks at Topaz improve the model. But most of the AI detail that's being created is actually there in the source image.

As an example, my output from the Raw converter is not sharpened. I apply a sharpening layer that I can switch off before downsampling, or perhaps mask it on critical places in the image before upsamping or Gigapixel AI scaling.

Cheers,
Bart
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bwana

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Re: raw conversion with AI Gigapixel
« Reply #2 on: July 11, 2019, 09:31:40 am »

thank you for your reply. Since I am processing Fuji RAF files, I use capture one. I dont think it does layers well. So My workflow would have to be C1 pro for raw conversion cropping, culling, export to tiff in prophoto rgb-> adobe PS for capture sharpening and exposure adjustments-> AI clear then AI gigapixel for upscaling -> back to adobe PS for exposure, curves, clarity, temp adjustments, creative sharpening, etc -> export to final tiff.
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Bart_van_der_Wolf

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Re: raw conversion with AI Gigapixel
« Reply #3 on: July 11, 2019, 09:56:26 am »

thank you for your reply. Since I am processing Fuji RAF files, I use capture one. I dont think it does layers well.

Capture One offers Adjustment layers e.g. for Exposure, Clarity, White Balance, Color Balance, and what have you, but I'm not clear on what causes the artifacts you mentioned. If they are Sharpening related, you can use a TIFF Export recipe which has C1 sharpening disabled.

Quote
So My workflow would have to be C1 pro for raw conversion cropping, culling, export to tiff in prophoto rgb-> adobe PS for capture sharpening and exposure adjustments-> AI clear then AI gigapixel for upscaling -> back to adobe PS for exposure, curves, clarity, temp adjustments, creative sharpening, etc -> export to final tiff.

You can then try to either add Capture Sharpening on a layer in PS, and save that as the basis for Gigapixel AI, or you could even try to skip Capture Sharpening and see how for Gigapixel AI can take you as it adds more detail than is in the source file. Then you only need to see if the upscaled result can be further improved by some additional processing.

I have found that Gigapixel AI can add so much credible detail to a file, that one can wonder if the additional steps before upscaling really add much to the upscaled result. I know that when I'm very careful, I can improve the source file to be used by Gigapixel by tweaking the sharpening locally, but it may be hard to see the effect of that in the final printed output.

So, a sanity check won't hurt, because Gigapixel is a gamechanger as far as my workflow is concerned.

Cheers,
Bart
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Bart_van_der_Wolf

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Re: raw conversion with AI Gigapixel
« Reply #4 on: July 11, 2019, 12:45:13 pm »

One thing I've learned, is that one has to be very careful in avoiding sharpening halos.
When magnified, they will stick out like a sore thumb.

So, if I do want to do Capture Sharpening before upscaling with Gigapixel AI, I use a Luminosity Blend-if layer in Photoshop or Affinity Photo that avoids clipping near high contrast edges, and edge contrast over-shoots if tweaked.

Cheers,
Bart
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