Scaling contest

[Michael Thaler]

On Thursday 30 June 2005 23:35, Casper Boemann wrote:

> Also my code handles selections on the fly. Clears the original and places
> the transformed image back. Your code would never be able to do that unless
> it too had to copy the images to a temporary paintdevice, and I have a
> strong feeling that this is where I'm loosing time.

OK, that definitely is an advantage. I just checked the GIMP. It scales the 
selection, too. If I understand correctly, a selection is just another layer, 
isn't it? So in prinicple I could just rescale the selection like I rescale 
an image?

By the way, the GIMP is quite a bit faster scaling images, I think.

> Well If I shifted by a whole pixel I could, but I don't, so I can't. The
> weights work on subpixel precision.

Maybe I don't understand, but I think you also can precalculate the weights if 
you do not shift by a whole pixels. You just need to calculate the weight for 
one pixel because you shift each pixel in a line by the same amount.

Greetings,
Michael