Re: [Texmacs-dev] [TeXmacs] New experimental Pdf export facility

[Joris van der Hoeven]

Hi Max,

On Sun, Nov 10, 2013 at 02:15:24AM +0100, Massimiliano Gubinelli wrote:
> Handling of images is a problematic issue. To embed images in PDF we need to 
> convert them to PDF before, at the moment I use ImageMagik since it is an 
> easy way to do.  I would like to discuss more deeply the handling of images 
> in TeXmacs. We rely on various methods and it is quite confusing to me. I 
> think we should settle down to some standard way of doing, independent of 
> platform if possible. Our requirements are the following:

ImageMagick provides the richest set of conversion routines.
Yet, I am not sure that it handles everything.
For this reason, I designed our mechanism for easily
adding converters whenever certain conditions are met.
The downfall of this method is that conversion becomes
quite dependent on system installations, which makes
debugging harder.  We might try to include a small number of
most powerful tools to the standard distribution so as to
guarantee minimal correct behaviour.

> The graphic backend needs a bitmap for the image.
> The ps backend needs a eps file for the image.
> The pdf backend needs a pdf file for the image.
> 
> How to proceed to support the largest number of image format in reliable way? 
> For example if I have a jpg image I would like to retain the compression in 
> the pdf and in the eps. 
> 
> Can we rely on Qt?

I think that it does not support all possible formats.
There is also SVG, for instance.

> Should we ship ImageMagik and Ghostscript by default to support these 
> conversions?

It seems that Ghostscript is still needed for rendering Postscript.
But maybe Poppler will now be a better option; I don't know.
In any case, we still want to provide Postscript <-> Pdf converters.

> Should we try to convert the formats to EPS by hand and then use GS to 
> convert them to PDF?

We currently do so.

> I’m a bit lost.

I understand.  Maybe someone could investigate in detail and
send us an overview of supported formats and conversions for
various tools, taking quality (bitmap / vector graphics) into account.

Best wishes, --Joris