DOCBOOK: Image scaling (was Re: DocBook TC Meeting Minutes: 15 Jan2002)

[Norman Walsh <ndw at nwalsh dot com>]

/ Yann Dirson <ydirson@fr.alcove.com> was heard to say:
| What I think we should do is to rework this part of DocBook.
|
| Is it really necessary to add any of these informations ?  I can't
| think of any of those parameters that is not layout-oriented.  I guess
| that all of them should be handled by the stylesheet, at least as far
| as printed output is concerned.  For HTML output, I'm afraid that
| could cause some problems, but the complexity of the solution does not
| change the problem IMHO.

I think it breaks down like this. Imagine that "image.eps" is 6in wide
and 10in deep.

<imagedata fileref="image.eps" width="3in" depth="5in" scalefit="1"/>

Renders the image at a size of 3in by 5in. (I think specifying only the width
or depth should have the same effect; specifying width="3in" depth="3in" should
scale the figure anamorphically.)

<imagedata fileref="image.eps" width="3in" depth="5in"/>

Renders the 6in x 10in image in a 3in x 5in space (we don't have an
attribute to control whether the image would be cropped or
overprinted, so you'd get whatever the stylesheets say).

<imagedata fileref="image.eps" scale="120%">

Renders a 7.2in x 12in image.

<imagedata fileref="image.eps" width="100%" scalefit="1"/>

Renders an image scaled to a width (with properly scaled depth) of
100% of the available area. (What constitutes the available area
depends on the context, of course. In print, it would usually be the
column width.)

<imagedata fileref="image.eps" width="100%"/>

Renders the 6in x 10in image in space equal to the width of the
available area. (we don't have an attribute to control whether the
image would be cropped or overprinted, so you'd get whatever the
stylesheets say).

| Opinions ?

We have all the attributes we need, and we need all the attributes we
have. (That some of this is presentational and not strictly semantic
is something we have to live with, I think.)

                                        Be seeing you,
                                          norm

-- 
Norman Walsh <ndw@nwalsh.com>      | The First Amendment is often
http://www.oasis-open.org/docbook/ | inconvenient. But that is besides
Chair, DocBook Technical Committee | the point. Inconvenience does not
                                   | absolve the government of its
                                   | obligation to tolerate
                                   | speech.--Justice Anthony Kennedy,
                                   | in 91-155