Hi,
thank you very much to all who provided comments to the topic. However,
I have to admit that I have some difficulties to figure out what they
mean for my proposal.
The current proposal is to state the following:
"Thumbnails *shall* be saved in the PNG format.
Note: Current desktops display thumbnail images within squares of up to
256 pixel width and height. While this specification does not define
upper or lower limits for thumbnail image sizes, implementations should
only use image sizes that are displayed with a reasonable quality if
scaled to fit into 256x256 pixel square."
So, is it suggested to add some wording for
- a 128x128 bit minimum size, and/or
- 24 bit per pixel, and/or
- alpha transparency?
And is it suggested to add them as normative requirements, or only as
informal guidelines (i.e. a note)?.
My opinion is that the minimum size and alpha transparency are
indirectly covered by my proposal, because it states that one "should
only use image sizes that are displayed with a reasonable quality if
scaled to fit into 256x256 pixel square."
That means that is clear that image sizes smaller than 128x128 won't be
a good choice, and that one for thumbnails that are not squares either
has to provide images that are not squares, or has to add transparent bits.
The 24 bit color item may be added.
I personally have a preference for stating these things in a
non-normative way in the future. Simple reason is that the "optimal"
image size and parameters depend on the platform, and may change in the
future. I further believe that implementors have an interest in storing
high quality thumbnail images anyway, and regardless whether we specify
minimum requirements.
I therefore propose to extend the note above as follows:
Note: Current desktops display thumbnail images within squares of up to
256 pixel width and height, and 24 bit per pixel. While this
specification does not define upper or lower limits for thumbnail image
sizes, implementations should only use image sizes that are displayed
with a reasonable quality if scaled to fit into 256x256 pixel square."
However, while I have a preference for that solution, I have no
objections to adding one or more of the requirements to the normative
text, if there is majority for this in the TC, and/or if no objections
are raised to this approach. It therefore would be good if those who
believe we should add normative minimum requirements could indicate
that, and those who have objections for adding them, too, so that I get
some guidance how to adapt the proposal, if required.
Thank you and best regards
Michael
Florian Reuter wrote:
> Dear TC
>
> I have some additional comments from our desktop team (Federico Mena Quintero