[Digikam-devel] idea: "make digikam trustworthy" metabug

[Sebastian Röder]

> I would like to second Gilles.
>
> First a comment to rotation and JPG: Every better photoviewer supports the
> EXIF rotation flag. So if you use or can correct the rotation flag there is
> no need to have an active rotation or a special jpeg lossless rotation
> (that digiKam also supports, when it knows the filetype) at all.
>
> The only thing you have to know when working with digiKam is, that when you
> use the IE you work with raw picture data like in every other graphic
> editor (e.g. gimp, krita, cinepaint, photoshop) The problem is not a
> limitation of the IE - its the other way round. If the IE could only
> manipulate JPGs I would not use digiKam any longer.
>
> You use the wrong format - its simple as that. You have to understand that
> JPG is an im- & export format. Do not use it in a complex workflow if you
> have high quality demands. JPG as a lossy format is designed for transport
> - that why you can find it in every camera and every photo web service. Its
> minimize the level of storage and bandwidth. These are  expense factors for
> digicams and web services. But when it come to quality you will not find
> jpeg any longer, then RAW, Tiff and PNG rules.
>
> But you really see a visual difference when watching JPEGs written with 99%
> quality settings from the IE?
>
> I also think there is one limitation with JPEG and IE: The quality setting
> should be visible and adjustable in the "save as" dialog when using a lossy
> file format. The simple save comand is dangerous. I hear too often that
> people lose image details cause they used to use a 65%-75% default JPEG
> quality setting for web and slideshows.
>
> Bye
>
>   Thorsten

Sorry if my post was unclear - I did NOT want to change how digikam works 
internal and it is OK for me to accept that jpg image saving is lossy in IE 
due to the jpg file format.

What I want to improve is to give the user more feetback about it - with 
tooltips, improved dialogs and so on. The idea of the meta bug was to collect 
ideas in which areas this improvements can happen.

When I got the internals right, then in Album mode all manipulations even to 
jpg are lossless thanks to file format specific kipi plugins that incorporate 
jpeg lossless. So there must be NO exeption of this rule (I started this post 
as a reaction of the auto rotate not lossless bug report). I hope this is the 
only exeption and that it will be fixed soon. Stiil I see the need to tell 
the user in an clever way that Album mode is were he should do things like 
rotate images (cause if he does it in IE and saves to jpg it's lossy!).

Second area to improve is as already mention by you the save dialog in IE. 
Here one might e.g. preselect PNG as default format to save manupulations and 
drop a warning of the lossyness when the user changes it to jpg. This is what 
I mean by "trusworthyness" - giving the user more feetback about what digikam 
does with the images, thus making the internals more transparent to the user 
(or let me say the digikam design approach) without forcing the user to study 
the internals in (technical) detail.

I must admit I do not have the time to do this work in the next two weeks or 
so, I'd like e.g. to talk to the usability people about it. But I will work 
on it as soon as possible. As a preparation from my point of view collecting 
ideas on where this omprovements can tale place is  a good thing (TM).