[pdftex] Best bitmap image format?

[gnwiii at gmail.com]

On 2/25/06, Robin Fairbairns <Robin.Fairbairns at cl.cam.ac.uk> wrote:
> hans h writes:
>
> > Olivier Lefevre wrote:
> > > I must embed application snapshots in a document. Which format will
> > > work best as far as pdftex is concerned? The snapshot tool can save in
> > > all the usual bitmap formats (e.g., gif, png, jpeg) and also as eps
> > > and pdf but for a bitmap image that is not very natural.
> >
> > black and white bitmap : png
> > color bitmap           : jpg
> > vector                 : pdf
> > metapost               : mps
>
> why do you suggest a "colour bitmap" should be represented using jpeg?
> -- for screen shots it seems a really unfortunate choice.
>
> as martin did, i too would recommend png for this application; though
> i do regularly use jpeg for photos (which is what it was designed for,
> i believe).
>
> robin
>
> (aside: i worked on the standardisation of png -- not on the technical
> stuff, just the words going round it -- and we had a definite
> instruction that png is just as good for colour as b&w).

Color is a much harder problem than B&W.  AFAIK,  PNG supports a
single gamma value, but many programs, including pdftex, ignore that
or use an assumed value.

Olivier's sample PDF uses DeviceRGB.  This may be fine for documents
intended for screen viewing (people who view the documents with screen
shots probably use similar displays), but there can be color issues
getting to hardcopy that you wouldn't have
with PDF's created using tools that support color management.

The "size" problem in the sample image may be a result of the vendor
assuming a certain
"dots-per-inch" for the display.

--
George N. White III <aa056 at chebucto.ns.ca>
Head of St. Margarets Bay, Nova Scotia