Phredreeke, on 18 January 2021 - 08:52 AM, said:
Keep in mind the sprite in Tea Monster's screenshot is of the upscale before it is downscaled to the final size. This is how it looks after downscaling/sharpening/palettisation (without the new gun)
Unfortunately downscaling/palettising does not entirely solve all the issues with AI upscales that we have.
Don't get me wrong, your result is very good. But with what ESRGAN can do at this moment, whatever resolution the upscale ends up at is still low on details compared to a hypothetical image that was created at the target resolution from the start (e.g. from a hi-res model). I think this might partially account for the slightly "blurry" look of the resulting sprites.
ESRGAN sharpens/brings out the details that are present in the source image, but can't add more than that. That was my point. The trick here is that when the source has enough detail the upscale might look "bland" but since the image is complete (e.g. you see the complete shapes of the Trooper's head, torso, limbs etc.), it is not as noticeable. But with the pistol, it was reduced to a handful of pixels in the original sprite so ESRGAN has trouble bringing up a coherent shape, hence it becomes apparent that the upscale is imperfect. But this imperfection is implicitly present in the entire image, not just where it stands out. But that's how I understand the entire problem, currently.