It should be quite a simple job to adjust the black point for a bitmap to make any shade of grey truly black. It you have a bitmap editor with a levels control, you can adjust the end points of the black-white range of image. At the extreme you can compress the entire brightness range into just black and white (no grey in between), but with a small range you can get a grey scale scan looking pretty black and white.
Footleg
Thanks for asking that question Michael
I have the same problem, but I had not bothered to think about changing the
linework colour.
I just tried a simpler approach (that leaves the header and grid coordinates
black). I will use this from now on.
symbol-colour group all [60] #makes everything grey
colour map-fg [97 86 38] #add some colour
And check out this code to make the grid grey
http://therion.speleo.sk/wiki/doku.php/metapost?s[]=change&s[]=grid&s[]=symb
ols#special_symbol_examples
Code to change grid symbols from cross hairs to continuous lines
Thanks
Bruce
(I don't know how to change the pen colours)
-----Original Message-----
From: therion-bounces@speleo.sk [mailto:therion-bounces@speleo.sk] On Behalf
Of Michael Wasmund
Sent: Tuesday, 19 May 2015 12:00 p.m.
To: therion@speleo.sk
Subject: [Therion] Redefining PENA...PEND to draw lighter
Hello,
Does someone have metapost code to redefine PENA...PEND to draw grey instead
of black?
Why I need this:
My survey consists of 80% scanned bitmaps and 20% drawn scraps.
The bitmaps are "grey", not black (can't make them better using image
processing).
The drawn scraps then stand out and look ugly compared to the bitmaps.
I know how to redefine individual symbols (walls etc.) to be grey instead of
black,
but rather than redefining a large symbol set I'd rather redefine the PENs -
if possible.
Regards,
Michael.
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