[GRASSLIST:4483] Re: how to generate high resolution image?

[Glynn Clements]

Victor Wren wrote:

> > Xueming Wu wrote:
> > 
> > > I cann't find any tool that can run under unix/linux and
> > > convert ps to wmf through the web. I tried to use "gs".
> > > And the image is better. But the size of image is too
> > > large. 
> > > 
> > > Any idea or suggestion? 
> 
>  
> > Glynn Clements <glynn.clements at virgin.net>
> 
> > It may be possible to use a "chain" of converters, e.g. convert
> > PostScript to PDF, then PDF to WMF. [I only mention WMF because it's
> > one of Microsoft's own formats; I have no idea what PowerPoint
> > actually accepts.]
> 
> Powerpoint's support of vector formats is exceptionally poor. It
> does, at least as of Office '97, import EPS. As far as I'm aware,
> DXF is entirely unsupported. It does accept WPG (not very useful). 
> If there are any converters out there for PostScript to EPS (does
> Ghostscript do this?) then Powerpoint can import it.

Ghostscript includes a shell script, ps2epsi, which generates EPS
files.

> It will only display the preview image, but it will print out from
> the vector image.

1. Presumably that is only the case when using a PostScript printer? 
To do it for other printers would require a PostScript interpreter.

2. That doesn't help if he's using PowerPoint to drive a projector.

Do you know whether PowerPoint imports *any* vector formats? EPS
doesn't really count if it's only displaying the preview bitmap.

> Support for EPS is much better in the Mac version of Office
> (and always has been) but portability may suffer.

> I'm not sure what he's saying about the "size of the image" being
> too large. Is it creating too large a file, or is it too big for the
> page?

I presume that he meant file size.

> If the latter, it can just be dragged down to the correct size
> with no loss of detail (the whole advantage of a vector format). If
> the former, using EPS should help (WMF simulates curves via straight
> line segments -- boo hiss! -- which makes for much larger files, not
> to mention poor quality curves [EMF was supposed to fix this, but
> it's WORSE, supporting only circular curves, which is almost as
> useless as only supporting straight segments] -- though the presence
> of a bitmap preview in EPS will grow the filesize somewhat.)

That shouldn't be an issue here; GRASS vector maps don't use curves.

-- 
Glynn Clements <glynn.clements at virgin.net>