[Gimp-user] can't keep proportions

[Mattia <forums gimpusers com>]

thank you for the help, much appreciated.
this will cause the border to look uneven however, isn't there a work around to
this?
also, it's not clear to me why 400 x 200 and 420 x 220 is not keeping aspect
ratio? the vertical increases exactly the same amount of the horizontal....

> If you add the same number of pixels to both the width and the height
> the aspect ratio will change UNLESS the image is square (height =
> width) - this is a simple consequence of basic arithmetic.
>
> If you want the aspect ratio to be unaltered you will need to add more
> pixels on the shortest sides of the image than you do on the longest
> sides - how may more being determined by the aspect ratio of the
> original image.
>
> For example if the image was 400 x 200 pixels adding a 10 pixel border
> to all sides would give 420 x 220 - which alters the aspect ratio.
> Adding 10 pixels each side and 5 pixels top and bottom gives 420 x 210
> which preserves the aspect ratio.

-- 
Mattia (via www.gimpusers.com/forums)