[YesProcrast]

My approach: import unsharpened image from Darktable, scale down with NoHalo (added in GIMP 2.10, along with LoHalo), sharpen final image with unsharp mask. When downscaling a clean image, try 1-pixel radius, strength 0.35, threshold 0.05 as a starting point.

"None" interpolation is occasionally useful as well, in image with really striking edges.

Agreed that the older downscaling algorithms aren't great. My impression is that they do a nice mathematical job of downscaling, but not a great perceptual one.

[nickjj]

But then compare that to Photoshop where you don't need to use any external tools or play with a bunch of settings.

You just scale the image down and it looks flawless and takes like 2 seconds. In over 10 years of using Photoshop I never once noticed a blurry downscaled image, but the first time I used Gimp to resize an image I immediately saw a poor result. I used every resize strategy too (including NoHalo and LoHalo -- they are both really bad compared to Photoshop).

It makes working with Gimp for any web style graphics a huge hassle because down scaling images is something you do all the time, and it's not just the final image too. It's every layer you're working with. Having to export every layer into a third party app and then re-place it is a huge time sink.