[Digikam-devel] Speed of new filters

[Gilles Caulier]

2010/2/13 Julien Narboux <jnarboux at narboux.fr>:
> Gilles,
>
> Did you notice the speed of the new threaded filters (hsl for instance)
> ? it seems to me that they are far slower than they used to be.
> Did the old implementation computed the preview on the downscaled
> version of the picture ?

yes, it is. This is relevant of imageguidewidget to imageregionwidget
port. If you fit to window preview with imageregionwidget as
imageguidewidget do, you compute on whole image.

Imageguidewidget use a downscaled version of preview, in fact the
screen size of widget. This is why it's very fast. But of course
zoom/pan is not possible here.

Note : with imageregionwidget, the computation is done on visible
preview area, not always on whole image. If you zoom down on, the
computation will be done on visible part of image. In this case it's
fast.

Gilles