: How to resize a small image in Photoshop to a large image with smooth gradients and without noise? I'm looking for software, namely a Photoshop plugin, or any other software that would integrate
I'm looking for software, namely a Photoshop plugin, or any other software that would integrate with Photoshop on macOS to quickly and easily upscale small low-res images to much larger images with the highest resulting quality, that is with maximally smooth gradients while preserving edges and avoiding visual noise.
One plugin capable of this that is only available on Windows is Redfield Perfectum, which is btw an extremely old piece of software. The third image below was made with Redfield Perfectum.
If there's absolutely no Photoshop software available for this on Mac, please let me know if it's possible to achieve this effect with standard Photoshop features.
What the op asked (or the result in his question) was made with Surface Blur in Photoshop.
Try ON1 Resizer, It keeps gradients smooth, but borders and curves stay sharp without getting jaggy or subjectively thicker. Photoshop plugin, Mac and Win versions are available, for Mac and Win. It tries to guess what is noise or JPG artefact and at least try to remove it.
I use it when a high resolution version of the image isn't available and the needed enlargening (say 400%) is too much for Photoshop's own scaling.
In the following screenshot there are 2 different upscalings to 400%. The leftmost is from ON1 Resizer and the rightmost is made with Photoshop's Bicubic resampling.
As you see, ON1 Resizer hasn't especially succesfully removed JPG artefacts. Specialized denoisers do it better.
No enlargening software is a substitute for high resolution original image. At their best they guess right curves, borders and gradients, but they cannot recreate the missing detail.
There is no way to do this without quality loss. The best alternative I've come across recently is a free web service that uses machine learning letsenhance.io/
Depending on your image, the results can be a lot better than what Photoshop and similar software can do. But as long as you are working with raster images and not vectors, it will not be perfect