guidelines for authors of cave surveys

[Lev Bishop]

On Fri, 25 Oct 2002, Wookey wrote:

> You mention EPS saying that import of it is 'dodgy'. I really do think that
> you need to be able to read postscript and eps diagrams.

I'm with wookey on this. _Anybody_ can produce postscript (any computer 
system that isn't capable of doing a print-to-file with a postscript 
printer selected is not going to be capable of doing any other aspects of 
survey preparation). You're probably going to be turning the magazine into 
postscript anyway when you submit it to the printers, right? I'm not too 
up on publishing software but surely they all can read postscript? (The 
stuff I played with years ago certainly could). Also, as wookey said:

> It is the father
> of all vector formats and anyone using anything unix-derived can always get
> postscript out of it, but may stuggle to get anything else you can read. It
> is also hand-editable (at least for reasonably simple diagrams), which
> means you can fix a problem without access to the producing application,
> which is something that is ture of almost no other format.

Plus, it's Turing-complete, also true of almost no other format ;-)

Disadvantages:  Not everyone can preview their postscript output to verify
that it worked (but ghostscript is a free download for most platforms, and
in the worst case they could always copy their file to a postscript
printer). Significant editing of the drawing will probably be trickier for
you since not many things (if any?) import postscript for general editing
(more than simple cropping, scaling, etc). (But this isgoing to be a
problem I think with all vector formats - I reckon your only chance to be
able to conveniently edit a vector file will be if both you and the author
share the same software (and use that software's native format). In my
(limited)  experience it's rarely easy to edit vector files between 
applications, sometimes even between versions of the same software 
(haven't used recent versions of coreldraw but had a lot of this kind of 
problem with the early versions)).

> For scanned cave surveys it's worth pointing out that they are _extremely_
> compressible. a PNG or GIF (boo, hiss) will be something like 5% of the
> size of the scanned bitmap. In our experience reducing them to 4-colour
> (2bit) greyscale (for B&W surveys) produces sharp images with black blacks
> that compress excellently.

Indeed, although a lot of software seems to try to keep the in-memory
image uncompressed (and maybe with more than 2 bits per pixel) so having
lots of large high-res images in a document can eat memory much faster
than you'd like or would be suggested by the file size.

Lev