Sharpen AI doesn't work for me

I’ve tried several photos in tiff and jpeg with Sharpen AI on my iMac Pro, but it doesn’t improve any image I’ve tried. Instead, it adds patterned noise to shadow areas, esp. on low-texture areas like skin.

Cpu looks different than Gpu, in that the patterned noise isn’t quite as obvious with Cpu. Neither mode actually sharpens the images, although the patterned noise introduces high frequencies that may fool the eye to perceive more sharpness. Unlike the portraits I tried, A landscape image I tried looked sharper when processed, but it appeared to be just patterned noise overlaid on the ground. It was much less obvious that was what it was when the original image had a rough texture.

The images I’m testing with were all shot with a Nikon D810 or Z7, so are quite large (4912x7360 to 5504x8256), if that matters.

It’s hard to tell why this isn’t working for me. The examples on the website don’t look this way.


Thanks for this comment , I thought I was alone with the patterns I was seeing in the final image!!! They are sharper yes, but, they show something odd specially when looking at skin.

Best wishes.

I tried Sharpen AI for the first time yesterday and can’t see that it helps. I’m using Win 8.1 and running Sharpen AI standalone. The photo was taken at an event called Dance Flurry in Saratoga Springs, NY in mid-February.

The first image is “before.” The second image is “after.” I used setting of 90 and 60 on the first two sliders.

Bob, I took your original picture (though the size is probably not original) and ran through Sharpen AI using the Stabilize function. You can see a dramatic sharpening here. I’m on a Windows 10 PC.

I can never ignore the possibility of operator error! I tried Sharpen AI on the original image (you are right, I reduced the resolution to 850 horizontal) and it’s far better. It took a long, long time to process (I didn’t time it), enough that I wouldn’t use it unless I really had to. But I’m very pleased that the program does work.

Thank you!!

Bob, do you mean 850 pixels wide? That’s rather small. I’ve been wondering if an 8K wide photo is just too big because even a small amount of perceived blur is quite a few pixels wide with that size photo. The doc says something about a 10-pixel limit for de-blurring.

I ran a test on an image that was originally 8K wide and shrunk to 2K wide in PhotoShop, then cropped. Here are the original and two sharpened versions, one with sharpen at 0.9 and also with denoise at 1.0. The two sharpened versions do look sharper, but strangely noisy. Enlarging them shows that sharpening added patterned noise to the skin texture. Perhaps that’s just how the AI works.

stoneyb, I reduced it to 850 pixels wide for uploading here. The original is 4054 pixels wide. And of course I used Sharpen AI on the full-resolution image.

I also noticed noise artifacts if I pushed the sharpening/stabilizing up too high. I found that I needed to be content with a setting of 50, otherwise smooth areas such as the walls got visible artifacts. To clarify, I was using the Stabilize feature.

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I initially used sharpening of 0.5, but it didn’t make enough difference to be worthwhile.

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I am uploading 1 cut of a photo, to check on the odd artifacts sharpen AI do to my photos. It was a TIFF file, Saved as Tiff and with Photoshop finally to jpg, so you can see it.

I don’t like these strange stuff… Opinions or ideas???

I didn’t for me either Stoneyb, I posted a small portion of one photograph down in this chat lines …