Re: [Gimp-developer] Save/export, option to go back to old behaviour

[Graeme Gill <graeme2 argyllcms com>]

Simon Budig wrote:
> As soon as the User does some little tiny editing we no longer can
> discern reliably between invented bits and important bits.

You don't have to though - the lossy compression algorithm
does that for you.

> The whole point we're trying to make and which you refuse to understand
> is, that "they already agreed to and want" only applies for images they
> created themselves from scratch. It breaks down immediately when they're
> working with images from other sources, like the clueless marketing
> droid sending you a jpeg logo file.

I'm not following your logic at all. When all you've got
is lossily encoded image source, you can't get the bits
back again. You can choose to save back to the original
file format or not. Unless you add something that needs lower
compression or lossless storage and you know it, there is
no reason not to save back to the original format with
a similar compression ratio, since no visual information
will be lost compared to the original, and that's the nature
of what you are working with.

> Here the user does *not* do a concious descision towards a lossy file
> format. He did *not* agree to loose bits on saving even when he opened a
> JPEG. 

But low value information was missing from the start, and saving to
jpeg isn't going to visibly loose any further information - that's
the nature of the format, and the trade-off (given a certain quality
setting) that it implies. If as a user you are not aware of
the nature and side effects of lossy compression, then no making-it-hard
to-save-in-jpeg-by-default is going to solve the that, it's
just a meaningless obstacle that they will ignore.

> This whole "user indicates his intent by the file format he opens"
> just breaks down when working with images from other sources.

I don't follow you at all. The lossy format implies that images
are compressed. You can't get those bits back again. If you add
stuff that benefits from less compression, then you need to be aware
enough of it to change the compression ratio or save to a lossless file
format, _but there's nothing special about that_ - you have
to be aware enough to do that when creating something from scratch
in the first place and going through the process of saving it in
a portable file format.
99% of the time people opening jpegs will be adjusting and cropping
photo's, so assuming they are doing something out of the ordinary
and making it hard for them is simply bad UI IMHO.

Graeme Gill.