Re: DOCBOOK-APPS: Images & PDF output

["Kevin M. Dunn" <kevinmd@hsc.edu>]

Colin Paul Adams wrote:

>>>>> "Martin" == Martin Perina <martin.perina@ataco.cz> writes:

    >> > I use PNG images for HTML output, EPS images for PS
    >> output. But > what type of image format should I use for PDF
    >> output with > pdfjadetex?
    >>
    >> PDF format is best, actually, but PNG is second choice
    >>
    >> sebastian

    Martin> Ok, but when I have declared this:

    Martin> <mediaobject> <imageobject> <imagedata
    Martin> fileref="images/products.eps" format="EPS"
    Martin> align="center"/> </imageobject> <imageobject> <imagedata
    Martin> fileref="images/products.png" format="PNG"
    Martin> align="center"/> </imageobject> </mediaobject>

    Martin> pdfjadetex always takes EPS file even it shows error
    Martin> message:

    Martin>  ! LaTeX Error: Unknown graphics extension: .eps
    Martin> Is there some way to made jadetex use PNG file?
 

I use PNG for pdf output all the time. Your stylesheet will choose the
first "available" format, which is listed in the
preferred-mediaobject-extensions and acceptable-mediaobject-extensions
sections of your stylesheet driver. The trick is to leave EPS out of your
pdf stylesheet driver. I now use separate stylesheets for each output medium,
giving better control over each.

The way to think about this is that the stylesheet chooses the media format based on its own logic. It has no way of knowing what formats are recognized by TeX except for what you tell it in preferred-mediaobject-extensions, etc. If more than 1 format is acceptible, it will choose the first listed. In your case, your stylesheet includes EPS as an acceptible format and the stylesheet passes it on to let pdfjadetex deal with it.

Before changing your stylesheet, you could try just changing the order of your imagedata blocks, i.e.:
<mediaobject>
<imageobject>
<imagedata
 fileref="images/products.png" format="PNG"
 align="center"/>
</imageobject>
<imageobject>
<imagedata
 fileref="images/products.eps" format="EPS"
 align="center"/> </imageobject>
</mediaobject>

Of course, your DTD must support PNG graphics, which I assume it does if you are using it for html output. Docbook 3.1 and earlier does not support PNG graphics. I'm not sure about 4.0. I use the GDP variant of Docbook 3.1, which is identical to 3.1 except for the addition of PNG support.

Here is the pertinent section of a pdf stylesheet driver (for version 1.54) which successfully uses PNG graphics:

(define preferred-mediaobject-notations
  (list "TEX" "JPG" "JPEG" "PNG" "linespecific"))

(define preferred-mediaobject-extensions
  (list "tex" "jpg" "jpeg" "png"))

(define acceptable-mediaobject-extensions
  (list "gif" "bmp"))

(define acceptable-mediaobject-notations
  (list "GIF" "GIF87a" "GIF89a" "BMP"))

Note the absense of EPS as a notation. I would include EPS in my postscript stylesheet driver.
 

-- 
Kevin M. Dunn
kevinmd@hsc.edu
Department of Chemistry
Hampden-Sydney College
HSC, VA 23943
(804) 223-6181
(804) 223-6374 (Fax)