Re: [Gimp-developer] Tuning and choosing resampling methods in GEGL/GIMP

[Elle Stone <ellestone ninedegreesbelow com>]

On 10/23/2017 10:03 AM, Øyvind Kolås wrote:
> This is what an adaptively increasing the OFFSET0 constant for
> significant downscaling in the sources might achieve - do note that
> what is meant by significant downscaling here is when scaling down to
> below 1% of original size - even in such scenarios nohalo will already
> be doing a good job. 

OK, that sounds less scary than the commit message!

As an aside, with today's high-pixel-count cameras, we are already at 
the point where resizing an image for display on the web might get the 
downscaling somewhat close to 1%. Resizing a 6000px wide image to 600 
pixels - that's 10% for a 24 megapixel camera, and there are cameras 
with much larger sensors out there.

> I believe that even without further enhancement
> we should use nohalo as the default sampler.

Normally I only resize single-layer images, or at most images with a few 
layers, so the speed of nohalo hasn't been a concern, and I do have 
nohalo set as the default. But there are cases when users will want to 
operate on large layer stacks.

Is the revised version of nohalo fast enough to handle a large image 
size with a lot of layers, even for various transforms? There doesn't 
seem to be a cancel button for various transformations for cases where 
users might not have checked the default settings before setting in 
motion a tranform that will take a long time.

Best,
Elle