Re: [docbook-apps] Images in PDF appear too large

["Chris Chiasson" <chris@chiasson.name>]

Assuming the matrix of pixels for an image is fixed, changing the dpi
of the picture is like telling the receiving application that the
image takes up different physical sizes:

example:
A 100 pixel by 100 pixel picture at 100 dpi (in both horizontal and
vertical directions) = 1 inch by 1 inch picture.

Supplying the same pixels and saying the picture is at 300 dpi will
give a 1/3 inch by 1/3 inch picture.

This doesn't happen in web browsers because they ignore picture dpi, AFAIK.

So, it makes sense that your 300 dpi picture is smaller if it has the
same pixel content as the other pictures.

I assume you already knew all of this and that the scaling attributes
of DocBook are confusing to you. In that case, can we start over? I am
lost.

On 4/27/07, T.G. Mutato <throw6617@gmail.com> wrote:
> Setting ignore.image.scaling to 1 definitely has an effect Chris --
> basically it gives the same result as if no size information was
> included at all.
>
> What I've come up with recently is that the best way to get a decent
> looking, non-scaled image using FOP 0.93 is to set the resolution of
> the image to 96dpi. If you look at the attached very short DocBook
> document, you'll see three inline images being included -- the only
> difference between these images is that the dpi is set differently
> (72, 96, and 300 dpi) -- all three images have the same pixel
> dimensions.
>
> In testimage2.pdf, you can see that the graphic that comes closest to
> being displayed at the correct size is the 96dpi version with no
> specification for width, depth, contentwidth, or contentdepth. As soon
> as any sizes are specified (even when the sizes are the actual sizes
> of the image), the images are displayed incorrectly.
>
> The testimage2a.pdf file uses the same xml source, but was created
> using the ignore.image.scaling that you suggested. In this file, the
> 96dpi version still looks the best, but it doesn't matter if specify
> dimensions or not; the ignore.image.scaling causes them to be changed
> to "auto" in the FOP output anyway.
>
> On 4/27/07, Chris Chiasson <chris@chiasson.name> wrote:
> > I think I was thinking of this (but I can never be too sure :-) ):
> > http://docbook.sourceforge.net/release/xsl/current/doc/fo/ignore.image.scaling.html
> >
> > On 4/27/07, T.G. Mutato <throw6617@gmail.com> wrote:
> > > Are you referring to scalefit="0" Chris? If so, It's already in there...
> > >
> > >
> > > On 4/27/07, Chris Chiasson <chris@chiasson.name> wrote:
> > > > there is an ignore scaling parameter
> > > >
> > > > On 4/27/07, T.G. Mutato <throw6617@gmail.com> wrote:
> > > > > If attachments work then you'll see an example of a short DocBook file
> > > > > with several image tests, both block and inline as well as the FO and
> > > > > PDF output. I couldn't find any combination (although I'm sure I
> > > > > missed a few) where the images were sized properly using FOP 0.93;
> > > > > they all looked too big. Using the XEP processor was a bit better,
> > > > > although not perfect either.
> > > > >
> > > > > Getting images to NOT scale turns out to be a lot tougher than I ever
> > > > > thought it would be.
> > > > >
> > > > > tgm
> > > > >
> > > > > On 4/26/07, T.G. Mutato <throw6617@gmail.com> wrote:
> > > > > > The example
> > > > > >
> > > > > > <imagedata fileref="images/image.png" format="PNG" scalefit="1"
> > > > > > width="100%" contentdepth="100%"/>
> > > > > >
> > > > > > was just one of the many I tried Bob. Even something very simple like
> > > > > >
> > > > > > <imagedata fileref="images/image.png" format="PNG"/> didn't work for
> > > > > > the inline image. I also tried specifying the actual width and height
> > > > > > of the graphic but that didn't work either; it still looked to big.
> > > > >
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> > > > >
> > > >
> > > >
> > > > --
> > > > http://chris.chiasson.name/
> > > >
> > >
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> > >
> >
> >
> > --
> > http://chris.chiasson.name/
> >
>
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