Re: [Gimp-user] can't keep proportions

[Jay Smith <jay JaySmith com>]

Mattia,

You said:

> 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....

It sounds to me like the problem is that you are confusing "same amount" 
with "same proportion".  They are _not_ the same thing.

Increasing 200 to 220 is a proportional increase of 10%.

If you increase 400 by 10%, that becomes 440, _not_ 420!

Jay


On 12/19/2016 03:18 PM, Mattia wrote:
> 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.

--
Jay Smith

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