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Author Topic: More Topaz AI Sharpen Banding!!  (Read 4410 times)

kers

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    • Pieter Kers
Re: More Topaz AI Sharpen Banding!!
« Reply #20 on: May 06, 2019, 06:53:33 am »

I think the product is not mature and it is not very helpful that you have too scrutinize the whole image to see if something is messed up after using Sharpen AI.
At most it can save an already bad image in some occasions.  That can be important of course, but for general purpose i would not like to use it.
With todays lenses and sensors, the sharpen- as well as the noise-problems are not so relevant anymore.
Most noise that you see 100% on screen almost completely disappears in print. On screen the 100% images is not used in 99% of the occasions, usually a 25% image and then noise is hardly an issue.
The artifacts and uneveness produced here i find much worse than a regular noise pattern.
« Last Edit: May 06, 2019, 10:08:39 am by kers »
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Pieter Kers
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bobfriedman

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Re: More Topaz AI Sharpen Banding!!
« Reply #21 on: May 06, 2019, 09:30:22 am »

Kind of grew tired of some discussions with kindergarten pupils imposing as wise old men ;).

Hmmm.. IMHO this level of arrogance is off topic.
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Bob Friedman
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bobfriedman

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Re: More Topaz AI Sharpen Banding!!
« Reply #22 on: May 06, 2019, 09:31:12 am »

I think the product is not mature and it is not very helpful that you have too scrutinize the whole image to see if something is messed up after using Sharpen AI.

Quite agree. I think this applies to the entire AI suite.
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Arlen

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Re: More Topaz AI Sharpen Banding!!
« Reply #23 on: May 06, 2019, 09:55:16 am »

I find all three of the AI programs that I have (disregarding JPEG to RAW AI, which I haven't tried) useful enough to be glad that I own them. But I will be glad when the bugs are worked out. Actually the bug that currently bothers me the most, and should be the easiest to fix, is that Sharpen AI totally messes up a PS Smart Object workflow. If you use any Topaz Studio adjustment/application on an SO, it comes back labeled as Sharpen AI. And if you click on that smart layer to edit it, it opens up as Sharpen AI, too. Even if you haven't used Sharpen AI at all. So the ability to edit Topaz Studio applications on a smart object is lost. This bug has been reported by many people for months. I think the popularity of these programs has overwhelmed Topaz, and they need some more staff.
« Last Edit: May 07, 2019, 10:21:15 am by Arlen »
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faberryman

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Re: More Topaz AI Sharpen Banding!!
« Reply #24 on: May 06, 2019, 11:17:42 am »

I think the popularity of these programs has overwhelmed Topaz, and they need some more staff.
Or perhaps they should wait until the bugs are worked out before releasing a new version. I have held off purchasing any of their products because of all the bugs reported here and elsewhere.
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JaapD

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Re: More Topaz AI Sharpen Banding!!
« Reply #25 on: May 07, 2019, 01:08:50 am »

I agree. I think it is however a pretty big achievement with these Topaz AI programs to perform better than the currently best in class programs such as Neat Image and Focus Magic. This is unfortunately on a case by case basis and the results are currently not reliable, certainly not in a batch workflow.

Recently I clearly saw good incremental achievements made, especially on AI Gigapixel, and as far as I can see the future looks promising but indeed the bugs need to be sorted out. Topaz needs to prove themselves that their audience is not the hobby kind of snappers but the pro photographers as well, in need for quality, reliability and reproducibility.

Regards,
Jaap.

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kirkt

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Re: More Topaz AI Sharpen Banding!!
« Reply #26 on: May 07, 2019, 10:29:08 am »

There's now also a thread on Topaz Sharpen AI on GetDPI on this: Topaz artefacts

Here's my post with some test results:


Further it was suggested in the thread that the raw converter can have an effect but the thread shows there is little difference between Lightroom and C1, and I can't imagine Topaz not training their AI models on these two quite popular and widely used raw converters.

It was further tested and the artifacts do not appear when exporting the file without downsizing and then running through Sharpen AI

However exporting a downsized tiff (8 bit and 16 bit) gave the same artifacts as running sharpen AI on a jpeg.

So it seems downsizing is the culprit leading to the artifacts in solid colour areas.

I have reported this issue to Topaz this is what I got back:
 I find the advice kind of lame, since final sharpening for output size is usually done as the last step and at output resolution (at least that's how I get the best results, YMMV) and not as a first step before making any adjustments. I find capture sharpening in Lightroom (and C1) more than adequate and don't need Topaz sharpen AI for that step.

I'd be interested in your experiences (similar or otherwise) or some suggestions how to avoid this issue on downsized raw converter exports.

It seems like the artifacts in your test image appear as a result of the algorithm struggling with the uniform area of sky next to the edge of the image.  I took your top image (LR output) into PS and extended the canvas from 1333 pixels tall to 1600 pixels tall, with the canvas extension applied to the top of the canvas.  I duplicated the original image and flipped it vertically, mirroring the sky pixels along the top edge and giving the extended border a healthy 250+ pixels of mirrored extension.  I ran Sharpen AI at default (Sharpen mode) on both the original, where I reproduced the artifacts that you demonstrate, and on the extended, mirrored version.  The artifacts appear on the extended, mirrored version, but at the edge of the image again, leaving a clean image at the original edge of the image, where the mirrored pixels are.  The artifacts areas appear regularly spaced along the boundary of the image and are arranged in similarly appearing clusters.

These artifacts are analogous to edge artifacts from FFT filtering or naive deconvolution or tone mapping a 360° x 180° equirectangular panorama without repeating edge pixels or having an edge-aware tone mapping algorithm.

See attached: red arrows indicate the mirror axis for the repeated edge pixels; yellow arrows indicate artifact clusters.

Kirk
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kirkt

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Re: More Topaz AI Sharpen Banding!!
« Reply #27 on: May 07, 2019, 10:46:02 am »

I also tried an experiment with your image where I used a vertical pixel offset (295 pixels downward) to make the cement wall wrap around the bottom of the image and appear at the top of the image.  This offset aligned the original top of the wall with the top edge of the image boundary, so that the image appears to have the cement wall hanging from the top of the image.  I ran Sharpen AI on the image, default Sharpen values, and no artifact appeared along the top edge of the offset image.  Upon applying a negative offset to reposition the image to its original appearance, the image is artifact-free, without having to mirror the broad, uniform sky area pixels to achieve the same output.

So, it would appear that the top edge of the image may be prone to artifact if it contains areas of broad, uniform tone/color, whereas it will be okay if it contains detail.

A kludge to experiment with and verify might be that if you are getting artifacts in images with broad, uniform areas of color or tone at the top of your images, offset the image so that detailed areas of the image are positioned along the top of the image and then run SharpenAI, then apply negative offset to return the image to its original position.

Kirk
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Arlen

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Re: More Topaz AI Sharpen Banding!!
« Reply #28 on: May 07, 2019, 10:51:26 am »

Thanks for those experiments, Kirk. Your results are consistent with what I've been seeing with not only Sharpen AI, but also Gigapixel AI.
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pegelli

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Re: More Topaz AI Sharpen Banding!!
« Reply #29 on: June 04, 2019, 01:37:16 pm »

The recent program update (about a week ago) fixed the issue for me.

I spotted no more artifacts in downsized LR or C1 exports when applying Sharpen AI.

Also the Denoise AI seems to work a lot better, mainly less artifacts in smooth areas close to highly detailed ones.

See here for the latest discussion on GetDPI on the Topaz AI programs.
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pieter, aka pegelli
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