Printing greyscale line drawings
Harriet Bazley
scan them in and do some quite sophisticated processing on them to
heighten contrast, blur lines, etc. But the results seem to be quite
unusable if printed back onto paper again.
The reason why seems fairly obvious: shades of grey that give the
impression of soft lines on the screen are rendered by the (B&W laser)
printer as widely spaced dots, which is fine for reproducing shades in
photographs or solid masses of colour, but very unsatisfactory when
attempting to print line art. I can get better results by
manipulating the scanned sprite until almost all the lines are solid
black, but this inevitably emphasises smudges and errors as well, and
makes pencil sketches look like pen&ink work - also, the printed
version is always paler than what appears on the screen, which means
it's very much a hit and miss process trying to guess how much
overcorrection is needed to get it to show up. Black comes out as
black. Very dark greys seem to come out as pale greys.
Is there a simpler way round this? (where 'this' is the problem of
printing solid grey lines)
--
Harriet Bazley == Loyaulte me lie ==
Life, don't talk to me about life....
Michael Gilbert
I doubt such a beast exists. Assuming it did, though, there would need
to be the ability to specify pen colour as a grey tone and to use a
range of grey pens rather than colour ones.
To go further into the realms of technological fantasy, it might well
be possible to design a plotter which uses pencil and understands the
correlation between pressure and colour...
More seriously, though, laser printing works like etching or
lithography, and looking at the tricks those techniques use to moderate
shades may help. That and a higher resolution printer, of course.
Cheers
Mike
--
Michael Gilbert: in his own write
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http://www.lewisgilbert.co.uk/access for Acorn peer-to-peer tools
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David Buck
The only other thing which comes to mind would be to convert it to a vector
image and then it may be possible to improve the printout by giving the
lines more thickness.
> To go further into the realms of technological fantasy, it might well
> be possible to design a plotter which uses pencil and understands the
> correlation between pressure and colour...
>
And the ability to lower the pen gradually to account for the reduction in
nib length, and to resharpen automatically.....
--
David Buck
2D CAD for RISC OS at www.risccad.freeuk.com
Rob Davison
> I can make pencil sketches. Thanks to Computer Concepts I can even
> scan them in and do some quite sophisticated processing on them to
> heighten contrast, blur lines, etc. But the results seem to be quite
> unusable if printed back onto paper again.
>
> The reason why seems fairly obvious: shades of grey that give the
> impression of soft lines on the screen are rendered by the (B&W laser)
> printer as widely spaced dots, which is fine for reproducing shades in
> photographs or solid masses of colour, but very unsatisfactory when
> Is there a simpler way round this? (where 'this' is the problem of
> printing solid grey lines)
Tried a modern inkjet?
http://www.luminous-landscape.com/tutorials/digital_b-w.shtml
See also the recent review of the Epson 2200 on the same site.
No idea how you'd drive such a beast from RISC OS. GIMP-Print possibly?
Rob.
--
Maple Glen http://www.mapleglen.co.nz/
Images http://www.pbase.com/mapleglen/
Every sunrise is different.
Tim Powys-Lybbe
The first question is whether you can use your computer successfully as
a photocopier. You start with a drawing on paper. Most modern
photocopiers will now copy such very well. But will your computer
setup do so?
If you can get your setup to do a good photocopy, the problem may still
be with your setup and not the program. It could be that what you see
on the screen is NOT what you get on the printer. The printer is OK
(photocopying) so it indicates that the screen isn't.
Then there are two further things to consider. First you have to work
at high dots per inch to print successfully. I would not go for less
than 300 and might consider 600 dots per inch. Ensure your scanner is
set for this high level. It produces a very large file, of course.
Secondly you must not save the graphic in any lossy format such as JPEG
as this rapidly loses definition. As my graphic work is very limited,
being zero of an artist, I only use sprite files and never reduce the
definition of these.
Sorry if you know any (all?) of this already and apologies for any
teaching of grandmother to suck eggs!
--
Tim Powys-Lybbe t...@powys.org
For a miscellany of bygones: http://powys.org
John Cartmell
Have you tried using colour instead of black?
--
John Cartmell john@ followed by finnybank.com 0845 006 8822
Qercus magazine FAX +44 (0)8700-519-527 www.finnybank.com
Qercus - the best guide to RISC OS computing
alan.calder
Had some similar problems when reproducing a friend's pencil sketches for
wine labels.
My first thought was to scan at a higher resolution - at least 300 to 600
dpi. Seems to make a difference (if you aren't already doing so).
Next was to wonder at your comment "Thanks to Computer Concepts". When I
had a CC scanner long ago ISTR that it was good device but limited in the
range of greys it could produce. I think much scanning was done at 16
greys and that the 256 grey mode was 'pseudo' in some sense - actually
producing fewer greys but 'creating' them in some way. I think 300dpi was
its maximum resolution anyway.
Scanning in colour at 24bit can improve things also - don't know why -
maybe my scanner just works better like that or perhaps the outputs more
printer friendly!
Have you tried using an inkjet rather than the laser? I find that it often
produces better results with greys, perhaps due to slight spreading of the
droplets.
Cheers
Alan
--
Alan Calder, Milton Keynes, UK.
Tony Williams
> The reason why seems fairly obvious: shades of grey that give
> the impression of soft lines on the screen are rendered by the
> (B&W laser) printer as widely spaced dots, which is fine for
> reproducing shades in photographs or solid masses of colour, but
> very unsatisfactory when attempting to print line art.
[snip]
I've been having a similar (sort of) problem recently,
trying to print TIFF files. They were compressed to
CCIT4 fax images and the 90x90dpi original resolution
just does not sit well with the laserjet's 600x600.
Lines too thin and everything barely readable.
ITSTM that the problem is one of dot-size. When the
printer prints a 90x90dpi image it does it with it's
own 600x600dpi dot size.... which produces a similar
dotted effect to the one you are seeing.
What seems to be needed is a prog that takes a sprite
file, looks at it to see which pixels are ON, then
creates a second sprite file where surrounding pixels
have also been turned ON.
OO OOO
ie, from P to PO or even P to OPO
OOO
Something to increase the effective dot size, so that
it is compatible with the dpi of the original image.
--
Tony Williams.
Brian Carroll
Powys-Lybbe <t...@powys.org> wrote:
> In message of 31 Oct, Harriet Bazley
> <baz...@feathermail.co.uk> wrote:
[Snip]
> > Is there a simpler way round this? (where 'this' is the
> > problem of printing solid grey lines)
> The first question is whether you can use your computer
> successfully as a photocopier. You start with a drawing on
> paper. Most modern photocopiers will now copy such very well.
> But will your computer setup do so?
[Snip]
I agree with what Tim says about this. The best way I have found
to 'photocopy' is to use !ArcFax along with David Pilling's TWAIN
and a rather old Epson GT-7000 scanner. This provides plenty of
room for experimentation with resolution, contrast, etc, during
the scan (set to B+W or Greyscale). A very large TIFF file is
produced which I do not save. The file can be viewed and printed
with offset margins and at any scale from within ArcFax.
Brian.
--
______________________________________________________________
Brian Carroll, Ripon, North Yorkshire, UK bric at f2s dot com
______________________________________________________________
Mr John FO Evans
<to...@ledelec.demon.co.uk> wrote:
> What seems to be needed is a prog that takes a sprite
> file, looks at it to see which pixels are ON, then
> creates a second sprite file where surrounding pixels
> have also been turned ON.
>
> OO OOO
> ie, from P to PO or even P to OPO
> OOO
I..M..ter or rather DpingScan has a 'slight blur' setting which should do
just this.
John
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Mr John FO Evans
selection of pencil lines on paper.
I used my old HP scanner an HP laserjet in both Postscript and PCL modes
and a Tectronix Phasar printer in Postscript mode. Scanning was at both
300 and 600dpi.
No file modification was done.
By far the best result was when using the Tectronix printer in Postscript
mode but the HP in Postscript mode was a close second. By far the worst
result - clearly showing Hariet's problem was the HP printer in PCL mode.
There was a slight improvement when the original scan was done at 600dpi
and this was most apparent with the HP in PCL mode.
Ian Fitzgerald
Tony Williams <to...@ledelec.demon.co.uk> wrote:
Most of the issues are covered:
1. Tonal resolution
2. dpi
Scan in colour at high resolution
Print in colour - even on B and W laser - at high resolution
Ensure that the output of your image manipulation software does represent
want you see on-screen - check it in another image-display application
Consider changing scanning or printing hardware
--
Ian Fitzgerald
ianf at ozemail dot com dot au
Jack Evans
Try this. It's worked very well for me although my starting point has
been line drawings printed in books, some of the 'originals' being poor
photocopies eg of old Punch cartoons.
Scan the picture with DPingScan at 300dpi and Grey (8bpp). Save as a
sprite into Photodesk . Click on the 'Image processing with the air
brush' Photodesk tool icon and from the 'Image processing effects'
window that comes up click on the Equalise button. The graph displayed
shows the distribution of the 256 shades of grey in the image from black
to white.
Almost certainly there will be gaps at the extreme ends of the spectrum
indicating that the image lacks intense white and intense black, but in
any case experiment with dragging the vertical dotted lines towards the
centre, clicking each time on the eye icon which toggles, until you get
the optimum result and then save it. I then B&W laser print from OPro to
the appropriate image size dimensions.
I've done hundreds of pictures this way and once you've become familiar
with it it's a doddle. But of course you need Photodesk: this feature
alone has made it a worthwhile investment for me.
Regards
Jack
--
Jack Evans Bristol UK
mailto:ja...@notsoljsevans.co.uk Drop the 'notso' to reply
Peter van der Vos
> I can make pencil sketches. Thanks to Computer Concepts I can even
> scan them in and do some quite sophisticated processing on them to
> heighten contrast, blur lines, etc. But the results seem to be quite
> unusable if printed back onto paper again.
>
I use a little different solution. I scan the drawing in
about 300 dpi, pure black/white. I then load the image in
paint and remove the incorrect pixels with the brush. After
this I vectorise (?) the image using Tracer.
What I get is a draw file I can scale without problems of
pixelation and still a small filesize.
Good luck,
Peter
Harriet Bazley
Ian Fitzgerald wrote:
[snip]
> Consider changing scanning or printing hardware
>
I suspect the latter is probably the answer - although I've had the
same problems (or worse: I don't think she was doing any image
manipulation) when sending artwork for publication in commercial
fanzines. Of course, I don't know what software she was using....
(If anyone actually bought my B7 novel "Not to Know" you'll have seen
exactly what I mean - the illustrations practically disappeared in most
places!)
--
Harriet Bazley == Loyaulte me lie ==
Those of you who think you know everything are annoying those of us who do.
Harriet Bazley
> In article <da4fb4c24...@freeuk.com>,
> Harriet Bazley <baz...@feathermail.co.uk> wrote:
> > I can make pencil sketches. Thanks to Computer Concepts I can even
> > scan them in and do some quite sophisticated processing on them to
> > heighten contrast, blur lines, etc. But the results seem to be quite
> > unusable if printed back onto paper again.
>
> > The reason why seems fairly obvious: shades of grey that give the
> > impression of soft lines on the screen are rendered by the (B&W laser)
> > printer as widely spaced dots, which is fine for reproducing shades in
> > photographs or solid masses of colour, but very unsatisfactory when
> > attempting to print line art.
[snip]
> Have you tried using colour instead of black?
>
Might be tricky using a grey-level scanner and a black and white
printer. :-)
--
Harriet Bazley == Loyaulte me lie ==
Everyone is entitled to one really BIG mistake
Tim Hill
<alan....@argonet.co.uk> wrote:
> My first thought was to scan at a higher resolution - at least 300 to
> 600 dpi. Seems to make a difference (if you aren't already doing so).
Many have said this but just to add 2p:
My ancient HP 3-in-1 1150c is quite remarkable at scanning even at
fax-fine resolution and handwriting - with a pen - is reproduced clearly.
However, the relatively feint nature of pencil will challenge it even at
"1200 dpi" at whatever the color (sic) setting.
Harriet, have you considered inking over your illustrations before
scanning? After all, pencil sketches have never really been the norm in
books, have they?
--
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... "Sleep seldom visits sorrow; when it doth, it is a comforter" Tempest, Act ii, Sc.1
John Cartmell
Harriet Bazley <baz...@feathermail.co.uk> wrote:
> On 1 Nov 2005 as I do recall,
> John Cartmell wrote:
> > In article <da4fb4c24...@freeuk.com>,
> > Harriet Bazley <baz...@feathermail.co.uk> wrote:
> > > I can make pencil sketches. Thanks to Computer Concepts I can even
> > > scan them in and do some quite sophisticated processing on them to
> > > heighten contrast, blur lines, etc. But the results seem to be quite
> > > unusable if printed back onto paper again.
> >
> > > The reason why seems fairly obvious: shades of grey that give the
> > > impression of soft lines on the screen are rendered by the (B&W laser)
> > > printer as widely spaced dots, which is fine for reproducing shades in
> > > photographs or solid masses of colour, but very unsatisfactory when
> > > attempting to print line art.
> [snip]
> > Have you tried using colour instead of black?
> >
> Might be tricky using a grey-level scanner and a black and white
> printer. :-)
The first is no problem - add colour later - but I didn't click that you only
had a monochrome printer. ;-)
Which printer? It may still be worth trying on the right setting and may make
some difference.
Robert Seago
create a line drawing which could be printed in monochrome. If so does it
work on Iyonix?
--
Regards from Robert Seago : http://www.users.zetnet.co.uk/rjseago
John Cartmell
Robert Seago <rjs...@zetnet.co.uk> wrote:
> Does anyone remember a program which loaded a photo and did its best to
> create a line drawing which could be printed in monochrome. If so does it
> work on Iyonix?
If not take a look at Qercus 272 where David Cowell and Henk Huinen illustrate
how to produce the effect.
cfe...@freeremoveuk.com.invalid
Robert Seago <rjs...@zetnet.co.uk> wrote:
> Does anyone remember a program which loaded a photo and did its best
> to create a line drawing which could be printed in monochrome. If so
> does it work on Iyonix?
>
Three versions? -
D Pillings !Trace
www.davidpilling.net/
!Tracer
www.xat.nl/en/riscos/sw/tracer/
I think RComp sell one as well - don't remember the name.
--
Colin Ferris Cornwall UK
alan.calder
> D Pillings !Trace
> www.davidpilling.net/
> !Tracer
> www.xat.nl/en/riscos/sw/tracer/
!ImageOutliner. Originally from Iota.
Harriet Bazley
Tim Hill wrote:
> Harriet, have you considered inking over your illustrations before
> scanning? After all, pencil sketches have never really been the norm in
> books, have they?
>
Yes, and I've long since found myself going back over the lines I want
to emphasise with a very heavy pencil and attempting not to ruin the
picture in the process. :-(
Trouble is, outline drawing with a nib really is a completely different
technique, requiring a different style of shading via varying thickness
of line etc, and it isn't one I ever got the hang of. :-(
You need a very bold and confident line - think George du Maurier....
But yes, I have thought of it and have even tried, using a mapping pen.
One of the problems is that you need a quite different paper surface,
as paper that will pick up soft pencils will blodge ink horribly. :-(
But you can get a reasonable facsimile of pen-and-ink drawings by
photocopying with heightened contrast and then touching up the result
with a fine nib where necessary. (I once tried colour photocopying,
but that was much worse, as you get a yellow fringe around each line!)
The analogue process seems to be much more effective than the digital -
but modern photocopiers don't seem to do it as well, and the more
expensive one are worse than the cheaper for this purpose. (Maybe they
*are* digital!)
--
Harriet Bazley == Loyaulte me lie ==
But I don't like Spam!!!!
Harriet Bazley
John Cartmell wrote:
> In article <d12038c34...@freeuk.com>,
> Harriet Bazley <baz...@feathermail.co.uk> wrote:
> > On 1 Nov 2005 as I do recall,
> > John Cartmell wrote:
[snip]
> > > Have you tried using colour instead of black?
> > >
> > Might be tricky using a grey-level scanner and a black and white
> > printer. :-)
>
> The first is no problem - add colour later - but I didn't click that you only
> had a monochrome printer. ;-)
> Which printer? It may still be worth trying on the right setting and may make
> some difference.
>
A fairly recently-acquired LaserDirect printer; it's *supposed* to be
able to do the 'photocopying' thing mentioned earlier in the thread in
tandem with the Scanlight software, but doesn't seem to like it. It's
not a function I've ever needed (nipping down to the corner shop is far
easier) so I never worried about it too much....
--
Harriet Bazley == Loyaulte me lie ==
It is impossible to enjoy idling thoroughly unless one has plenty of work to do
Elaine Jones
posted on 3 Nov 2005 by Harriet Bazley
I would like to add:
> On 2 Nov 2005 as I do recall,
> Tim Hill wrote:
>
>> Harriet, have you considered inking over your illustrations before
>> scanning? After all, pencil sketches have never really been the norm in
>> books, have they?
>>
> Yes, and I've long since found myself going back over the lines I want
> to emphasise with a very heavy pencil and attempting not to ruin the
> picture in the process. :-(
>
> Trouble is, outline drawing with a nib really is a completely different
> technique, requiring a different style of shading via varying thickness
> of line etc, and it isn't one I ever got the hang of. :-(
> You need a very bold and confident line - think George du Maurier....
Hmm, have you tried a good sable brush - or a Chinese brush (long and
fine)? It would take some practice but the flexibility of the brush
may be the answer.
--
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.RISC PC. Corwen, North Wales; Steam Traction;CMMGB&Yukon Volunteers.
John Cartmell
> > In article <d12038c34...@freeuk.com>, Harriet Bazley
> > <baz...@feathermail.co.uk> wrote:
> > > On 1 Nov 2005 as I do recall, John Cartmell wrote:
> [snip]
> > > > Have you tried using colour instead of black?
> > > Might be tricky using a grey-level scanner and a black and white
> > > printer. :-)
> > The first is no problem - add colour later - but I didn't click that you
> > only had a monochrome printer. ;-) Which printer? It may still be worth
> > trying on the right setting and may make some difference.
> A fairly recently-acquired LaserDirect printer; it's *supposed* to be able
> to do the 'photocopying' thing mentioned earlier in the thread in tandem
> with the Scanlight software, but doesn't seem to like it. It's not a
> function I've ever needed (nipping down to the corner shop is far easier)
> so I never worried about it too much....
You need to get it to realise that it's not printing simple blacks. Have you
tried using colour? ie getting it to print shades of colour rather than shades
of black.
charles
John Cartmell <jo...@cartmell.demon.co.uk> wrote:
> In article <ff8bc7c34...@freeuk.com>, Harriet Bazley
> <baz...@feathermail.co.uk> wrote:
[Snip]
> > A fairly recently-acquired LaserDirect printer; it's *supposed* to be
> > able to do the 'photocopying' thing mentioned earlier in the thread in
> > tandem with the Scanlight software, but doesn't seem to like it. It's
> > not a function I've ever needed (nipping down to the corner shop is far
> > easier) so I never worried about it too much....
> You need to get it to realise that it's not printing simple blacks. Have
> you tried using colour? ie getting it to print shades of colour rather
> than shades of black.
John; Harriet said she was using a LaserDirect. That's a B&W laser - no
colour.
--
From KT24 - in "leafy" Surrey
Using a RISC OS5 computer
alan.calder
Harriet Bazley <baz...@feathermail.co.uk> wrote:
> On 2 Nov 2005 as I do recall,
> John Cartmell wrote:
> > In article <d12038c34...@freeuk.com>,
> > Harriet Bazley <baz...@feathermail.co.uk> wrote:
> > > On 1 Nov 2005 as I do recall,
> > > John Cartmell wrote:
> [snip]
> > > > Have you tried using colour instead of black?
> > > >
> > > Might be tricky using a grey-level scanner and a black and white
> > > printer. :-)
> >
> > The first is no problem - add colour later - but I didn't click that
> > you only had a monochrome printer. ;-) Which printer? It may still be
> > worth trying on the right setting and may make some difference.
> >
> A fairly recently-acquired LaserDirect printer; it's *supposed* to be
> able to do the 'photocopying' thing mentioned earlier in the thread in
> tandem with the Scanlight software, but doesn't seem to like it. It's
> not a function I've ever needed (nipping down to the corner shop is far
> easier) so I never worried about it too much....
Ahh - the good ol' Laserdirect. Loved mine much but eventually abandoned
it (after maybe 9 years of reliable use) when I got my Kyocera FS3750.
Much better printing of greys by the Kyocera. This might be down in part
to the higher printing resolution - it can do 1200dpi as against the LD's
300dpi but ISTR that the RISC OS Postscript drivers only work at 600dpi but
even this is a great improvement. Oddly the Kyocera's LCD display says
that it is printing at 1200dpi so maybe it is regardless!
Anyway, back to the photocopying thing. My memory of this with the
Scanlight software was that it basically just did a straight b/w scan and
this is what you printed. Your corner shop must be in the next room to
make it quicker to go there! I still do a lot of 'photocopying' with my
scanner/laser and that surely is all a real photocopier does - scans and
prints. Scanning in grey and printing gives results as good as most corner
shops and a lot cheaper!
Cheers
Alan
PS Somewhere I have an unused toner cartridge for a Laserdirect. If I
ever find it you can have it for the postage.
John Cartmell
> [Snip]
Yes. Does the monochrome printer reproduce monochrome graphics in the same way
as it reproduces colour graphics? If not the difference may help.
Harriet Bazley
cfe...@freeRemoveuk.com.invalid wrote:
> In message <4dc3a20e...@zetnet.co.uk>
> Robert Seago <rjs...@zetnet.co.uk> wrote:
>
> > Does anyone remember a program which loaded a photo and did its best
> > to create a line drawing which could be printed in monochrome. If so
> > does it work on Iyonix?
> >
> Three versions? -
>
> D Pillings !Trace
> www.davidpilling.net/
>
I bought a copy of Trace second hand at the Guildford Show: ten years
old but very impressive, at least for the monochrome scans which is all
I've needed it for....
--
Harriet Bazley == Loyaulte me lie ==
But I don't like Spam!!!!
Harriet Bazley
Elaine Jones wrote:
> Quoting from message <9b70c8c34...@freeuk.com>
> posted on 3 Nov 2005 by Harriet Bazley
> I would like to add:
>
> > On 2 Nov 2005 as I do recall,
> > Tim Hill wrote:
> >
> >> Harriet, have you considered inking over your illustrations before
> >> scanning? After all, pencil sketches have never really been the norm in
> >> books, have they?
> >>
> > Yes, and I've long since found myself going back over the lines I want
> > to emphasise with a very heavy pencil and attempting not to ruin the
> > picture in the process. :-(
> >
> > Trouble is, outline drawing with a nib really is a completely different
> > technique, requiring a different style of shading via varying thickness
> > of line etc, and it isn't one I ever got the hang of. :-(
> > You need a very bold and confident line - think George du Maurier....
>
> Hmm, have you tried a good sable brush - or a Chinese brush (long and
> fine)? It would take some practice but the flexibility of the brush
> may be the answer.
>
I'm just not a good enough artist; the idea of pure line scares me
silly. My (self-taught) technique consists of sketching in cautious
lines in approximately the right places, and then working over and over
to build up a more confident approximation of the form. I don't
actually rub things out, unless they go very wrong and I need to blank
out a section of the picture, but I do lean heavily on the ability of
the pencil to produce extremely vague initial suggestions! The result
is a sort of amassed combination of shade and shape with the outline
emerging more by consensus than anything else. I only have the one
style of semi-outline drawing: I can't really manage pastel-type
shading, and I greatly admire and envy those cartoonists and pavement
sketch-artists who can set down a single accurate line and catch a
likeness in one stroke.
But I *can* catch a reasonably good likeness in my messy way. Well,
mostly, anyway. Sometimes it just goes essentially wrong....
--
Harriet Bazley == Loyaulte me lie ==
An atheist is a man with no invisible means of support.
Harriet Bazley
John Cartmell wrote:
> > > > On 1 Nov 2005 as I do recall, John Cartmell wrote:
>
> > > > > Have you tried using colour instead of black?
>
[snip]
> >
>
> You need to get it to realise that it's not printing simple blacks. Have you
> tried using colour? ie getting it to print shades of colour rather than shades
> of black.
>
It occurred to me this morning that the question I was *actually*
trying to ask is "Isn't there a better way of printing grey than
printing black with holes in it?" :-) But short of a printer that
actually lays down thicker or thinner layers of ink according to the
hue (?intensity?) required, I suppose there isn't....
I imagine your suggestion here is an attempt to provoke just this
behaviour; sadly it's not possible even to test it via the LaserDirect
drivers. Whilst on my old inkjet it was possible to *request* colour
printout but only actually have a black cartridge present, the
LaserDirect drive, having the advantage of being written for specific
hardware, knows very well that it can only print one colour at a time
and won't let you select more than one ink from the 3-colour and
4-colour printout menus!
--
Harriet Bazley == Loyaulte me lie ==
There are two ways to write error-free programs; only the third one works.
Harriet Bazley
alan.calder wrote:
[snip]
> Anyway, back to the photocopying thing. My memory of this with the
> Scanlight software was that it basically just did a straight b/w scan and
> this is what you printed. Your corner shop must be in the next room to
> make it quicker to go there! I still do a lot of 'photocopying' with my
> scanner/laser and that surely is all a real photocopier does - scans and
> prints. Scanning in grey and printing gives results as good as most corner
> shops and a lot cheaper!
So it would be -- if it worked. "Internal error - abort on data
transfer". :-(
(Also, I'm using a CC Scanlight 256 hand scanner + podule - the
scanner's pretty useless, tending to go very dark at the edges, but the
podule software/hardware's very impressive - and the number of
applications for which a 2-3 inch strip of scan comes in handy is quite
limited!)
--
Harriet Bazley == Loyaulte me lie ==
Oregano: The ancient Italian art of pizza folding.
Harriet Bazley
alan.calder wrote:
[snip]
> My first thought was to scan at a higher resolution - at least 300 to 600
> dpi. Seems to make a difference (if you aren't already doing so).
The scanner defaults to 200dpi/256 colours (well, greys!) but goes up
to 400dpi. However, the only time I've ever used the 400dpi setting in
earnest is in order to enlarge some tiny photographs by scanning them at
400dpi and then viewing the results in Paint, which assumes that all
sprites are 90dpi - it was really a very effective way of picking up
detail that wasn't previously visible!
My observation is that for scan resolutions of 400dpi at 256 colours,
only approximately one-third to one-quarter of the width of the scanner
head is actually used, presumably due to memory constraints. This
limits you to very small pictures indeed - but as I'm mostly scanning
in logos and stuff this isn't actually so much of a problem as those
with A4 flatbed scanners probably assume....
I normally scan pencil artwork in 16 colours at 200 or 300 dpi;
especially if it's going to be printed, the aim is for an all-but-
monochrome output, and there's no point in introducing colours that are
just going to have to be approximated out again.
>
> Next was to wonder at your comment "Thanks to Computer Concepts". When I
> had a CC scanner long ago ISTR that it was good device but limited in the
> range of greys it could produce. I think much scanning was done at 16
> greys and that the 256 grey mode was 'pseudo' in some sense - actually
> producing fewer greys but 'creating' them in some way. I think 300dpi was
> its maximum resolution anyway.
I don't have the manual (which tells you a *lot* about the quality of
the software interface design! The one thing that had me frustrated at
the start was not realising that the dpi/colour switches on the scanner
itself have to be set up manually to match the software settings every
time you change the latter, otherwise you get seriously distorted
images), but so far as I can tell from the on-screen representation of
the results, when it claims to produce 256 greys it does so. In fact,
it does so to a degree of accuracy the machines of the era aren't
equipped to represent, due to not having a fully-programmable 256
colour palette.
It offers output in monochrome, 16, 176 and 256 greys, with the
palettes set appropriately. Unfortunately nothing else can actually
understand 176-grey-level sprites, so they come out weirdly
rainbow-coloured unless you load them into Impression and map them to
greys....
My main complaint about the scanner is that it always produces a grey
background staining in from the edges of the picture; this doesn't show
up much when scanning photos, but dark lines on a white background get a
spreading shadow near the edge, which basically reduces the usable
width of the scanner head.
>
> Scanning in colour at 24bit can improve things also - don't know why -
> maybe my scanner just works better like that or perhaps the outputs more
> printer friendly!
>
> Have you tried using an inkjet rather than the laser? I find that it often
> produces better results with greys, perhaps due to slight spreading of the
> droplets.
>
I got more or less the same results with the inkjet printer; if
anything, better results with cheaper paper, which I suspect
corresponds to your explanation of spreading of the droplets.
--
Harriet Bazley == Loyaulte me lie ==
Save energy: be apathetic.
Harriet Bazley
[snip]
> The first question is whether you can use your computer successfully as
> a photocopier. You start with a drawing on paper. Most modern
> photocopiers will now copy such very well. But will your computer
> setup do so?
No.
At least, the printer doesn't have a photocopier function, and the
photocopier function on the scanner doesn't work.
>
> If you can get your setup to do a good photocopy, the problem may still
> be with your setup and not the program. It could be that what you see
> on the screen is NOT what you get on the printer. The printer is OK
> (photocopying) so it indicates that the screen isn't.
>
> Then there are two further things to consider. First you have to work
> at high dots per inch to print successfully. I would not go for less
> than 300 and might consider 600 dots per inch. Ensure your scanner is
> set for this high level. It produces a very large file, of course.
Part of the problem is how to get the printer to output at anything
other than 90dpi, which is how the OS assumes it should render a
sprite. If I scan an image at 400dpi, what I get in any other
program (or if I reload an old scan into the scanning software) is in
effect a vastly magnified version of the image.
If I drop a sprite into a drawfile and scale it down to 50% of its
default size, does this print out at twice the dpi, or does it just
print out as a sprite scaled by the OS routines to 50%, i.e. degraded?
Sprites in Impression graphics frames display their dpi as part of the
graphics info, and here Impression claims that scaling pictures down
will improve their printing quality; in practice, I see no visible
difference between a sprite twice the size at half the scale and one at
'default' scale. I dare say this is because I'm not printing at high
enough resolution, but I'm sitting here looking at a set of sample
printouts, and I honestly can't see that the one supposedly displayed at
90dpi is any worse than the one supposedly displayed at 300dpi (and
printed using the LaserDirect's 600dpi setting, to give it the best
possible chance!) The only obvious difference is that the one sampled
down to half resolution and then printed at 90dpi (100% scale in
Impression) is larger than the original, while the one scanned at
300dpi and shrunk down after importing to 30% scale in Impression (thus
reporting itself as 300dpi in the graphic dialogue box) is the original
size.
But both sets of greys have got holes of about the same size. :-p
>
> Secondly you must not save the graphic in any lossy format such as JPEG
> as this rapidly loses definition. As my graphic work is very limited,
> being zero of an artist, I only use sprite files and never reduce the
> definition of these.
I always work on files as sprite files (as I don't have the tools to
manipulate any other format!) and only convert them if I want to send
them to PC users or put them on the Web.
--
Harriet Bazley == Loyaulte me lie ==
Confession is good for the soul, but bad for the career.
Harriet Bazley
spent an evening making some scanning/printing tests on the effects of
different resolutions. The results can't possibly be a realistic
representation, as I'm introducing errors and distorting the scale when
I re-scan the printout, but they do correspond more or less in degree to
what I'm seeing on the paper in front of me....
Here is an HTML page linking to the files discussed below:
http://www.bazley.freeuk.com/dpi/Scans.html
(Warning: these files are up to 400K each even as GIFs, and took
forever to upload from this end!)
First of all I took a quick drawing as an example. This is a study in
perspective - it's a picture of my right foot from almost directly
above. :-)
This is just stuck down on the back of some old dot-matrix printout,
and you can actually see the crease where it was folded at the bottom,
and a line of mirror-printing showing through from the other side of
the paper!
I scanned it in 16 colours at 300 dpi: image (1). (Of course, since
the OS assumes it's dealing with a screen-resolution sprite, the result
here is simply an enormous picture.)
Version (2) I processed via the Scanlight software as I would normally
do in order to clean up the 'noise' and emphasise the main lines of the
picture for printing: this reports that the output image is now
150dpi, since it has been sampled at a ratio of two pixels to one.
I printed the latter image as a graphic from Impression at three
different scales: '100%' (e.g. 90dpi), 150 dpi (reducing it back to
the size of the original drawing), and 300dpi (e.g. the normal printer
resolution). The "300dpi" version, in addition to being tiny,
actually looks the worst to me in terms of the relative proportion of
white space and dots where the original grey lines are concerned.
Reducing it has demonstrably sacrificed detail - you can't read the
mirror text any more - for no discernable gain of resolution in the
printout.
I scanned the "150 dpi" version back in (again, using the 300dpi
setting in 16 colours) as image (3). I got the edge of the scan
slightly wonky, which illustrates all too clearly the difference
between the fresh darkening of the background introduced here by the
scanner, and the large dots of the originally identical darkening from
the first scan - as rendered on paper by the printer!
I then took image (1), my 300dpi unprocessed scan, and printed this out
via Impression at a nominal 300dpi by scaling the image down as
before once imported. I repeated this exercise with the same document
after altering the printer settings to render the page at 600x600dpi -
ouch, that's slow! ;-)
You *can* definitely tell the difference between these two versions.
Ironically, however, the only thing that really shows up is that the
background 'noise' is of a finer resolution. I regret to say that the
actual artwork itself is almost identically dotty whether the printer
is set to 300 or 600 dpi - which is odd, because presumably the noise
and the lines were scanned at the same resolution?
Image (4) is a scan of the 600dpi printout - scanned back in at 300dpi,
admittedly, but it's pretty obvious that the resolution of the scan is
far higher than the effective resolution of the dot-screened printout!
If I compare image (3), which is what I'd normally have to settle for,
with image (4), using far more time and memory, two things seem obvious
to me. First of all, both are vastly reduced in quality from their
on-screen equivalents, images (1) and (2). Secondly, at least to my
eye, the gain in quality obtained by sampling and darkening the lines
so that the dots can run into each other actually outweighs the
theoretical gain of printing at twice the nominal resolution....
Image (2) renders best on screen and is the quality I'd normally use
for the Web. However, I don't have any way of equalling even that
supposedly low 90dpi quality on paper.
And just for interest: I 'cleaned' the latter sprite using
white filled triangle in Paint (my usual method!), reduced it to four
colours (having to take it off the Iyonix again to do so; for some
reason ChangeFSI under RISC OS 5 is capable of *displaying* 2bpp
sprites but refuses to create them!) and ran it through David Pilling's
Trace, having set the latter to a staggering error setting of 60 pixels
instead of the 0.84 default in order to get it to 'join the dots' with
such a ragged image. The result is... insanely complex, but just about
recognisable. It's not really vector graphics, in any meaningful
sense!
(Zipped, because it was gigantic and in the hopes of getting it out the
far end with the right filetype.)
For the record, and to avoid possible confusion: !Paint, hand-scanner,
printer and Creator software for GIF conversion were all running on the
A5000. Trace was running under Aemulor on the Iyonix (as I thought it
would take forever otherwise - I bought it for the A5000!) and ChangeFSI
was running on Martin's RPC 600.
--
Harriet Bazley == Loyaulte me lie ==
C++ - the language in which only friends can access your private members
Tim Hill
Harriet Bazley <baz...@feathermail.co.uk> wrote:
> If I drop a sprite into a drawfile and scale it down to 50% of its
> default size, does this print out at twice the dpi
Yes, this higher setting is then translated to the dpi setting of your
printer driver.
--
* Sick of BT? Leave them and reduce your phone bill by up to half.
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www.invalid.org.uk or email postmaster at invalid dot org dot uk
... "I hear, yet say not much, yet hear the more" Henry IV, Act iv, Sc.1
Tim Powys-Lybbe
> On 1 Nov 2005 as I do recall,
> Tim Powys-Lybbe wrote:
>
> [snip]
>
> > The first question is whether you can use your computer successfully as
> > a photocopier. You start with a drawing on paper. Most modern
> > photocopiers will now copy such very well. But will your computer
> > setup do so?
>
> No.
>
> At least, the printer doesn't have a photocopier function, and the
> photocopier function on the scanner doesn't work.
What I was meaning, was just scan the dtawin in, don't alter it and
then print it out. This is "photocopying". You should be able to get
a good image of your original printed out. If you can't then that has
to be sorted first.
<snip>
> If I drop a sprite into a drawfile and scale it down to 50% of its
> default size, does this print out at twice the dpi,
Yes, definition is not lost.
> or does it just print out as a sprite scaled by the OS routines to
> 50%, i.e. degraded?
No.
This is probably the greater part of an answer. You cannot print
successfully from Paint. You must put sprites into Draw which then
prints out at whatever size and resolution you have in Draw; there is no
degradation in Draw.
--
Tim Powys-Lybbe t...@powys.org
For a miscellany of bygones: http://powys.org
Tim Powys-Lybbe
(with fingers that obviously wandered off the frame and failed to
spell-check.)
> In message of 5 Nov, Harriet Bazley <baz...@feathermail.co.uk> wrote:
>
> > On 1 Nov 2005 as I do recall,
> > Tim Powys-Lybbe wrote:
> >
> > [snip]
> >
> > > The first question is whether you can use your computer successfully as
> > > a photocopier. You start with a drawing on paper. Most modern
> > > photocopiers will now copy such very well. But will your computer
> > > setup do so?
> >
> > No.
> >
> > At least, the printer doesn't have a photocopier function, and the
> > photocopier function on the scanner doesn't work.
>
> What I was meaning, was just scan the dtawin
^
drawing
druck
> It occurred to me this morning that the question I was *actually*
> trying to ask is "Isn't there a better way of printing grey than
> printing black with holes in it?" :-) But short of a printer that
> actually lays down thicker or thinner layers of ink according to the
> hue (?intensity?) required, I suppose there isn't....
Yes, a continuous tone printer, such as die sublimation will do this for
grey and colours, giving a photographic like result. However these are
speciallist printers which are only any good for graphics, and are too
slow and low resolution for anything else.
---druck
--
The ARM Club Free Software - http://www.armclub.org.uk/free/
The 32bit Conversions Page - http://www.quantumsoft.co.uk/druck/
Tony Williams
Harriet Bazley <baz...@feathermail.co.uk> wrote:
> Here is an HTML page linking to the files discussed below:
> http://www.bazley.freeuk.com/dpi/Scans.html
> (Warning: these files are up to 400K each even as GIFs, and took
> forever to upload from this end!)
The Windows Picture and Fax Editor, used in edit mode
and set to print as 'sized to 1x1 pages', printed Big
as a perfect grey-scaled A4 printout.
Printer = HP6P, running at 600dpi.
So what does the WPaFE do that !Paint doesn't do?
A 580kB DOS .prn file available for email, move the
attachment to the $ directory and just do an F12 and
then '*copy winprint printer:' from the command line.
Umm.... probably only compatible with Laserjets.
--
Tony Williams.
Mr John FO Evans
(postscript) set to photo quality and then rescanned at 300dpi. The
final image was a sprite of nearly 8Mbts!
The image on paper and the sprite were barely distinguishable from the
original gif. Using Impression made no significant difference.
I then cropped this sprite to a section of about 300Kbts and compared
it with a 75% jpeg of this section which was only 57Kbts - very little
difference.
This jpeg is a shade darker than the original and slightly lower contrast
but the graininess is only marginally greater than the original gif.
I am sure that the quality of the printout is because using postscript
makes the printer, rather than the driver, the generator of the printed
bitmap immage.
--
_ _________________________________________
/ \._._ |_ _ _ /' Orpheus Internet Services
\_/| |_)| |(/_|_|_> / 'Internet for Everyone'
_______ | ___________./ http://www.orpheusinternet.co.uk
alan.calder
Mr John FO Evans <mi...@orpheusmail.co.uk> wrote:
> I printed Harriets gif to A4 size using Ovation Pro on a Xerox Phaser
> (postscript) set to photo quality and then rescanned at 300dpi. The
> final image was a sprite of nearly 8Mbts!
[Snip]
> I am sure that the quality of the printout is because using postscript
> makes the printer, rather than the driver, the generator of the printed
> bitmap immage.
I have tried printing Harriet's original gif twice. First directly from
!Browse which produced two sheets of A4 from my Kyocera running in PS mode.
Actually about half the drawing was missing which I expect was because the
file was larger than the printer's memory could cope with. The output I
got however was fine tonallywith lots of greys finely shading off.
The next attempt was via Artworks with a much reduced, approx A6, image on
the page. Again finely delineated greys with no stepping effect.
I would guess, with John, that this is down to the printer being driven as
Postscript plus the effects of much more modern printer technology compared
to the Laserdirect.
Harriet's scanned examples show all the effects I remember from my
Laserdirect days of scanning the print of a previous scan. This can, done
repeatedly, produce quite artistic effects but the image inevitably
degrades remarkably. Nice to see the old Laserdirect printer software's
dot shape options in use again though!
Cheers
Alan
Chris Evans
<URL:mailto:baz...@feathermail.co.uk> wrote:
> On 1 Nov 2005 as I do recall,
> alan.calder wrote:
>
>
> [snip]
>
> > My first thought was to scan at a higher resolution - at least 300 to 600
> > dpi. Seems to make a difference (if you aren't already doing so).
>
> The scanner defaults to 200dpi/256 colours (well, greys!) but goes up
> to 400dpi. However, the only time I've ever used the 400dpi setting in
> earnest is in order to enlarge some tiny photographs by scanning them at
> 400dpi and then viewing the results in Paint, which assumes that all
> sprites are 90dpi - it was really a very effective way of picking up
> detail that wasn't previously visible!
>
> My observation is that for scan resolutions of 400dpi at 256 colours,
> only approximately one-third to one-quarter of the width of the scanner
> head is actually used, presumably due to memory constraints. This
> limits you to very small pictures indeed - but as I'm mostly scanning
> in logos and stuff this isn't actually so much of a problem as those
> with A4 flatbed scanners probably assume....
Scan in B&W ie. two colour that will:
1 Alow a much higher resolution
2 Give you no greys, therefore the printer will not have to dither
You may need to adjust the 'trigger' point for black if you source is not
very dark and you may need to touch it up in Paint.
Chris Evans
--
CJE Micro's / 4D 'RISC OS Specialists'
Telephone: 01903 523222 Fax: 01903 523679
ch...@cjemicros.co.uk http://www.cjemicros.co.uk/
78 Brighton Road, Worthing, West Sussex, BN11 2EN
The most beautiful thing anyone can wear, is a smile!
VinceH (real address)
[snips throughout]
> Here is an HTML page linking to the files discussed below:
> http://www.bazley.freeuk.com/dpi/Scans.html
> First of all I took a quick drawing as an example. This is a
> study in perspective - it's a picture of my right foot from almost
> directly above. :-)
Sheesh that's a hairy looking foot. Or were you wearing a
sock at the time? ;-)
> I scanned it in 16 colours at 300 dpi: image (1). (Of course,
> since the OS assumes it's dealing with a screen-resolution sprite,
> the result here is simply an enormous picture.)
I've printed this one out twice - once from RISC OS (via
Draw) and once from Windows (via Win Picture/Fax Viewer),
and both to the same printer - a HP Laserjet 4L[1].
The hatching on the Windows printout is much more
noticeable - it appears to have given an even spread of
dots, with the dot size varying according to how dark
the grey should be.
With the RISC OS printout, OTOH, the dots seem to have
been kept to the same size, and its the pattern/spacing
between them varies - more density for the darker greys
(obviously). To my eyes, this is the better printout of
the two.
I think you'll find this will also vary from printer to
printer - I have, at times, brought things home from one
place to print here, because the printer at that office
(a Samsung ML4600) produces noticeably worse results,
even though it's printing at the same resolution and
with the same (Windows) software.
[1] Which I've had since not long after the model was
first brought out, and it has proven to be an
excellent piece of kit. Other printers have joined
my setup and been sent packing, while this one has
looked smugly at them and said "you won't be here
long, upstart."
VinceH
--
http://www.softrock.co.uk http://www.webchange.co.uk http://www.vinceh.com
A bio with some actual bones for fido content:
http://www.vinceh.com/vinceh/
Never, under any circumstances, accept a blow job from a zombie.
Michael Harding
> spent an evening making some scanning/printing tests on the effects of
> different resolutions. The results can't possibly be a realistic
> representation, as I'm introducing errors and distorting the scale when
> I re-scan the printout, but they do correspond more or less in degree to
> what I'm seeing on the paper in front of me....
> This is just stuck down on the back of some old dot-matrix printout,
> and you can actually see the crease where it was folded at the bottom,
> and a line of mirror-printing showing through from the other side of
> the paper!
I can't recall where I picked up this tip, but I do know that if you
want to prevent black print showing through from the other side of the
paper, then place behind it a sheet of completely BLACK paper.
To obtain such a sheet, all you have to do is to open the top of a
photocopier and put nothing on the glass, and then photocopy nothing.
The result is a piece of black paper.
Can I say thank you for this thread? I've faced this problem of
copying pencil drawings and never knew how to tackle it.
Michael Harding
--
Rev. Preb. M. D. Harding mdha...@ormail.co.uk
Harriet Bazley
Chris Evans wrote:
[snip]
> Scan in B&W ie. two colour that will:
> 1 Alow a much higher resolution
> 2 Give you no greys, therefore the printer will not have to dither
>
> You may need to adjust the 'trigger' point for black if you source is not
> very dark and you may need to touch it up in Paint.
>
I have tried, in the past... and it just doesn't work. :-(
The results are always 'flat' and stencil-like, not to mention the fact
that areas of the lines are missing; it doesn't matter if I throw the
trigger point over to maximum, there are vital areas of a greyscale
picture that just don't register in monochrome. It's fine for true
black and white art, e.g. newspaper cartoons, but the results for
pencil pictures are as bad (and for much the same reason) as my B&W
printouts. They're recognisable, but they're a fractured parody of
the original.
http://www.bazley.freeuk.com/dpi/monoface.gif
http://www.bazley.freeuk.com/dpi/shadeface.gif
--
Harriet Bazley == Loyaulte me lie ==
Dawn: The time when men of reason go to bed.
Harriet Bazley
Tim Powys-Lybbe wrote:
> > On 1 Nov 2005 as I do recall,
> > Tim Powys-Lybbe wrote:
> >
> > > The first question is whether you can use your computer successfully as
> > > a photocopier. You start with a drawing on paper. Most modern
> > > photocopiers will now copy such very well. But will your computer
> > > setup do so?
[snip]
> What I was meaning, was just scan the drawing in, don't alter it and
> then print it out. This is "photocopying". You should be able to get
> a good image of your original printed out. If you can't then that has
> to be sorted first.
No, I can't - see sample sheets. :-(
The resemblance of the printout to the original can be increased by
over-correcting the scan, but a straight scan/print operation produces
a very inferior result.
[snip]
> You cannot print successfully from Paint. You must put sprites into
> Draw which then prints out at whatever size and resolution you have
> in Draw; there is no degradation in Draw.
>
Ah, that'll be why the scanner gives the option to 'save as Draw' (I
always assumed it was to preserve the displayed scale/rotation, if any).
Not much use if I'm trying to manipulate the output in bitmap packages,
though. :-(
(Given the small size of the scan head, I have, in the past, resorted
several times to scanning separate areas and pasting up a collage of
these snippets in Draw to reassemble them on a white 'canvas'!)
--
Harriet Bazley == Loyaulte me lie ==
You /really/ don't want to know.
Harriet Bazley
Michael Harding wrote:
> In article <a9c6d8c44...@freeuk.com>,
> Harriet Bazley <baz...@feathermail.co.uk> wrote:
> > This is just stuck down on the back of some old dot-matrix printout,
> > and you can actually see the crease where it was folded at the bottom,
> > and a line of mirror-printing showing through from the other side of
> > the paper!
>
> I can't recall where I picked up this tip, but I do know that if you
> want to prevent black print showing through from the other side of the
> paper, then place behind it a sheet of completely BLACK paper.
Oh, interesting - I never thought of that!
> Can I say thank you for this thread? I've faced this problem of
> copying pencil drawings and never knew how to tackle it.
>
Well, I'm not sure we're any further forward... other than in the need
to invest in top-end hardware.... :-)
--
Harriet Bazley == Loyaulte me lie ==
Do not underestimate the power of the Force.
Tony Williams
Harriet Bazley <baz...@feathermail.co.uk> wrote:
[snip]
> Well, I'm not sure we're any further forward... other than in the
What's top-end hardware?
Use Intergif to convert Big to a !Paint file.
1062KB, 1248W x 1743H, so it's a Portrait.
Drop it into Draw. Adjust Draw's page size until
the sprite is smaller than the page size. ie, Set
Draw to A2/Portrait.
A2/Portrait= 2x A4/P wide, by 2x A4/P high. So in
Draw, Select-All-->Transform-->Magnify-->0.5.
Bring up Draw's printer limits and pull the reduced
drawing into the printing frame.
Printer= HP6P.
600dpi, good printout, slightly better than the PC .prn.
300dpi, ok printout, slightly worse than the PC .prn.
150dpi, a touch too 'dotty'.
--
Tony Williams.
Martin Wuerthner
Harriet Bazley <baz...@feathermail.co.uk> wrote:
There is no need for top-end hardware, just do not use things that
belong in a museum. LaserDirect is definitely of the latter category.
The quality of greyscale drawings printed on a black & white printer
is mainly determined by the halftoning algorithm used. Halftoning is
the process of emulating a tonal range using purely colour dots (e.g.,
greyscales using purely black dots) distributed at the desired density
in more or less regular patterns on the page. Since this is the most
important thing as far as your problem is concerned, I am very
surprised you did not mention anything about which halftoning options
you used - each kind of printer driver gives you halftoning options,
some very few (standard drivers), some very complex settings
(TurboDrivers, and probably LaserDirect as well).
When I had a LaserJet 5 many years ago, the halftoning used by the
standard RISC OS drivers was reasonable, but not very good. The advent
of the TurboDrivers made a huge difference and gave stunning quality
in comparison - of course, you needed to set up the right kind of
halftoning. Did you really use a LaserDirect? If so, this puzzles me a
bit because the TurboDrivers were based on the LaserDirect software,
for which CC had written all their clever halftoning stuff, so I would
assume that the LaserDirect halftoning is far superior to that of the
standard drivers. Of course, there are lots of options and you can
easily get inappropriate rendering or poor quality by using the wrong
ones.
The halftoning used in the scanned printout looks very good to me - in
technical terms (which seems to confirm that it is from LaserDirect),
it is just the wrong kind of halftoning for that printer resolution
and for the kind of graphics you try to print. Which halftone options
did you use?
If you were to use the standard RISC OS drivers, you might want to try
error diffused printing for that kind of graphics.
Martin
--
---------------------------------------------------------------------
Martin Wuerthner MW Software http://www.mw-software.com/
ArtWorks 2 -- Designing stunning graphics has never been easier
spam...@mw-software.com [replace "spamtrap" by "info" to reply]
Martin Wuerthner
Harriet Bazley <baz...@feathermail.co.uk> wrote:
> The only obvious difference is that the one sampled
> down to half resolution and then printed at 90dpi (100% scale in
> Impression) is larger than the original, while the one scanned at
> 300dpi and shrunk down after importing to 30% scale in Impression (thus
> reporting itself as 300dpi in the graphic dialogue box) is the original
> size.
>
> But both sets of greys have got holes of about the same size. :-p
Yes because the "holes" you see are produced by the halftoning of the
printer driver, so they have nothing to do with the source data. If
you printed a solid grey rectangle from Draw you would get the same
"holes".
I suspect your lpi setting (lines per inch - the effective resolution
of the halftone as opposed to dpi which is the physical resolution in
terms of printer dot size) in the printer driver is too low.
Harriet Bazley
Martin Wuerthner wrote:
> In message <3950ccc54...@freeuk.com>
> Harriet Bazley <baz...@feathermail.co.uk> wrote:
>
> > On 6 Nov 2005 as I do recall,
> > Michael Harding wrote:
> >
> >> Can I say thank you for this thread? I've faced this problem of
> >> copying pencil drawings and never knew how to tackle it.
> >>
> > Well, I'm not sure we're any further forward... other than in the need
> > to invest in top-end hardware.... :-)
>
> There is no need for top-end hardware, just do not use things that
> belong in a museum. LaserDirect is definitely of the latter category.
But since it's contemporary with the software and hardware I'm using
for the scan and print process here (not to mention that they're all
Computer Concepts products - well, perhaps not the actual computer, but
the two podules probably count as hardware...) it's a definite
improvement on what I was using before. And as 99% of everything I
print for external consumption comes out of non-32-bit compatible
software, switching hard-copy output over to the Iyonix plus paying for
a new printer isn't exactly a priority; the system I have contains a
lot of highly sophisticated features for its age and works very well.
For everything else!
[snip]
> I am very surprised you did not mention anything about which halftoning
> options you used - each kind of printer driver gives you halftoning options,
> some very few (standard drivers), some very complex settings
> (TurboDrivers, and probably LaserDirect as well).
That just shows you how little I know about printer drivers.
I've never altered or even observed this setting; I believe I vaguely
remember discussion of halftone separations in the Impression manual....
Oh, here we are. "...only apply when outputting to a PostScript device
such as an [sic] typesetter... only change the screen angles if you are
experienced in producing half-tone separations." I think I can be
forgiven for writing it off and never looking at it again! But that's
all about colour, by the looks of it, so not the same as the
LaserDirect.
Hang on. Other manual....
This looks like it. Halftone patterns and lpi.
"Dot screen 1: Intermediate shades are represented by circular dots.
There is a linear progression between no ink and solid ink as the shade
darkens.
"Dot screen 2: This also uses circular dots but with an 'S'-shaped
progression towards solid colour. This gives improved contrast on
some illustrations.
"Dot screen 3: This is the inverse of dot screen 1. That is, shades
are represented by circular areas of no ink.
"Line: This uses continuous lines rather than dots for half-toning.
Line screens are useful for creating effects but have limited general
use.
"Crosshatch: This uses square dots and produces an effect similar to
traditional photographic methods.
"Quad dots: A version of dot screen 1 that uses an arrangement of 4
dots in each halftone cell, arranged 2x2. This gives the effect of a
closer dot spacing for a given resolution. For example, a 45 lpi quad
dot screen looks like a conventional 90 lpi screen."
"Resolution: Most printers print intermediate shades as regularly
spaced dots of differing sizes. Light shades are printed as small
dots; dark shades as larger dots. *Resolution* determines the
spacing of the dots; the lower the resolution the wider the spacing.
Wider spacings can show a greater range of intermediate shades but the
individual dots are more noticeable.
"Resolution is measured in lines-per-inch (/lpi/). lpi is a
traditional printer measurement, which basically describes the halftone
dot spacing; for example, 20 /lpi/ means 20 dots per inch.
Resolution
lpi 300x300 dpi 600x300 dpi
100 9 18
90 11 22
60 25 50
45 44 89
36 69 139
30 100 200
/number of intermediate shades/
"Because of the special techniques used to achieve 600dpi vertically,
the number of intermediate shades is the same as 600x300.
"You should note that when the resolution is changed in the configure
dialogue box... Laser Direct does not automatically change the /lpi/
shown in the halftone dialogue box [could this be the problem?]. By
default the resolution will be set to 37.5 /lpi/ at 300 by 300 dpi -
when this is changed to 600 by 300 or 600 by 600, we recommend a
setting of 53 /lpi/."
"Separation angles: ...It is often useful to change the angle when
using the Line screen."
I must confess that I don't actually understand most of this; so far
as I can make out, it looks as if increasing the lpi reduces the number
of shades available somehow but reduces the size of the dots? (In the
specific case of my drawings, 4 shades would probably be ample!)
> The halftoning used in the scanned printout looks very good to me - in
> technical terms (which seems to confirm that it is from LaserDirect),
> it is just the wrong kind of halftoning for that printer resolution
> and for the kind of graphics you try to print. Which halftone options
> did you use?
>
> If you were to use the standard RISC OS drivers, you might want to try
> error diffused printing for that kind of graphics.
>
I used the default halftone setting, which seems to be... quad dot
screen. :-(
What a pity - I was thinking that from the description that one sounded
the most hopeful for improvement....
Lpi currently states 37.5 as per the manual.
There's also a mystery option box (unticked) for 'error-diffused
sprites', which apparently post-dates the manual, as it isn't mentioned
and doesn't appear in the screenshots!
--
Harriet Bazley == Loyaulte me lie ==
An atheist is a man with no invisible means of support.
Martin Wuerthner
Harriet Bazley <baz...@feathermail.co.uk> wrote:
> On 7 Nov 2005 as I do recall,
> Martin Wuerthner wrote:
>> I am very surprised you did not mention anything about which halftoning
>> options you used - each kind of printer driver gives you halftoning options,
>> some very few (standard drivers), some very complex settings
>> (TurboDrivers, and probably LaserDirect as well).
>
> That just shows you how little I know about printer drivers.
> I've never altered or even observed this setting; I believe I vaguely
> remember discussion of halftone separations in the Impression manual....
>
> Oh, here we are. "...only apply when outputting to a PostScript device
> such as an [sic] typesetter... only change the screen angles if you are
> experienced in producing half-tone separations." I think I can be
> forgiven for writing it off and never looking at it again! But that's
> all about colour, by the looks of it, so not the same as the
> LaserDirect.
No, it is not necessarily for colour, but as it says, this option *in
Impression* is for PostScript only, so it is irrelevant in this
context. If you are interested in the technical background:
Practically all printer drivers except PostScript rasterize the
output, i.e., they transmit series of dots to the printer. The
halftoning has to be done as part of the rasterization process.
Therefore any halftoning option has to be in the printer driver and it
has to apply globally for the whole page to be printed. For
PostScript, each object to be printed (image, text line, shape) is
transmitted separately to the printer and the printer does the
halftoning itself, so you can choose a different halftoning option for
each image to be printed, but for that, the option cannot be in the
printer driver, it has to be in the application that does the
printing.
> I must confess that I don't actually understand most of this; so far
> as I can make out, it looks as if increasing the lpi reduces the number
> of shades available somehow but reduces the size of the dots?
Yes, precisely.
> (In the specific case of my drawings, 4 shades would probably be ample!)
4 shades is a bit too modest. Fortunately, the driver will do more
even at the highest lpi setting.
> I used the default halftone setting, which seems to be... quad dot
> screen. :-(
> What a pity - I was thinking that from the description that one sounded
> the most hopeful for improvement....
I recommend Quad dot screen, it is the best by a huge margin. This is
not your problem - your problem is the lpi setting.
> Lpi currently states 37.5 as per the manual.
Yes, and precisely that is the problem. This is too low for the kind
of effect you are trying to achieve. There is not a single screen
setting that is perfect for all types of graphics. Try a setting of 75
for a change and watch the difference! It cannot hurt to try 100 as
well.
> There's also a mystery option box (unticked) for 'error-diffused
> sprites', which apparently post-dates the manual, as it isn't mentioned
> and doesn't appear in the screenshots!
That is worth trying as well since it is directly relevant for your
situation. The technical details of this are probably not too
important. It is higher quality in many situations, in particular for
the kind of fuzzy drawing you have got but I doubt it will make a big
difference. Changing the lpi setting will have a greater impact.
Michael Harding
Harriet Bazley <baz...@feathermail.co.uk> wrote:
> On 7 Nov 2005 as I do recall,
> Martin Wuerthner wrote:
> > I am very surprised you did not mention anything about which
> > halftoning options you used - each kind of printer driver gives
> > you halftoning options, some very few (standard drivers), some
> > very complex settings (TurboDrivers, and probably LaserDirect as
> > well).
> This looks like it. Halftone patterns and lpi.
> "Line: This uses continuous lines rather than dots for
> half-toning. Line screens are useful for creating effects but have
> limited general use.
One of the "limited uses" I found was when I produced the parish
magazine. I used to use TurboDrivers with the setting "Line" to
produce photographs for publication via photocopier.
The result was superb - far superior to anything I've seen produced by
Windows machines - especially if I tweaked the contrast of photographs
in Publisher, to suit photocopier characteristics.
I think the reason for the advantage of Line screens with
photocopiers, is that when a photocopier scans the page before
printing it out, it's prone to miss some dots (a sort of moire
effect?): whereas with constant lines, of greater or lesser thickness,
the scanning is bound to register the lines.
That at least is my rationalisation. I can only add that it worked,
and no other variant was as good.
druck
> That just shows you how little I know about printer drivers.
> I've never altered or even observed this setting; I believe I vaguely
> remember discussion of halftone separations in the Impression manual....
> Dot screen 1:
> Dot screen 2:
> Dot screen 3:
> Line:
> Crosshatch:
> Quad dots:
Unfortumately its missing the one you really need, which is error diffused
dither - where single printer dots are deposited almost at random but in the
right proportion to create the correct shade but without any obvious halftone
pattern, which would be ideal for pencil line art. It was included in the
later Turbo Drivers and eventually Acorn's own drivers, but I don't know it
it made it in to any LaserDirect drivers.
Tim Powys-Lybbe
In message of 6 Nov, Harriet Bazley <baz...@feathermail.co.uk> wrote:
> On 5 Nov 2005 as I do recall,
> Tim Powys-Lybbe wrote:
>
> > > On 1 Nov 2005 as I do recall,
> > > Tim Powys-Lybbe wrote:
> > >
> > > > The first question is whether you can use your computer successfully as
> > > > a photocopier. You start with a drawing on paper. Most modern
> > > > photocopiers will now copy such very well. But will your computer
> > > > setup do so?
>
> No, I can't - see sample sheets. :-(
> The resemblance of the printout to the original can be increased by
> over-correcting the scan, but a straight scan/print operation produces
> a very inferior result.
Then nothing will work right if you can't do a quick print of the scan
and get a good picture of the original.
> [snip]
> > You cannot print successfully from Paint. You must put sprites into
> > Draw which then prints out at whatever size and resolution you have
> > in Draw; there is no degradation in Draw.
> >
>
> Ah, that'll be why the scanner gives the option to 'save as Draw' (I
> always assumed it was to preserve the displayed scale/rotation, if any).
> Not much use if I'm trying to manipulate the output in bitmap packages,
> though. :-(
Once you have manipulated it, save it as a sprite and put that in Draw.
art...@invalid.co.uk.invalid
druck <ne...@druck.freeuk.com> wrote:
> On 8 Nov 2005 Harriet Bazley <baz...@feathermail.co.uk> wrote:
>
>> That just shows you how little I know about printer drivers.
>> I've never altered or even observed this setting; I believe I vaguely
>> remember discussion of halftone separations in the Impression manual....
>
>> Dot screen 1:
>> Dot screen 2:
>> Dot screen 3:
>> Line:
>> Crosshatch:
>> Quad dots:
>
> Unfortumately its missing the one you really need, which is error diffused
> dither - where single printer dots are deposited almost at random but in the
> right proportion to create the correct shade but without any obvious halftone
> pattern, which would be ideal for pencil line art. It was included in the
> later Turbo Drivers and eventually Acorn's own drivers, but I don't know it
> it made it in to any LaserDirect drivers.
>
> ---druck
>
I may be wrong, but I seem to recall that it was possible to convert a
sprite to 1 bit per pixel in DPlingScan using FS dither and then to
load it into Impression and scale to 30% which gave 300dpi. Printing
this on the LaserDirect at 300 dpi matched dot for dot.
Arthur
--
Arthur Quinn
real-email arthur at bellacat dot com
druck
> In message <650ab4c6...@druck.freeuk.net>
> druck <ne...@druck.freeuk.com> wrote:
>
> > Unfortumately its missing the one you really need, which is error diffused
> > dither
>
> sprite to 1 bit per pixel in DPlingScan using FS dither and then to
> load it into Impression and scale to 30% which gave 300dpi. Printing
> this on the LaserDirect at 300 dpi matched dot for dot.
Certainly possible. For printing non sprites you might be able to use DP's
!SPrinter which I beleive supports 1bpp error diffused dither, although if it
doesn't you can always convert a higher depth down to this using DPlingScan
or ChangeFSI. Then print the resulting sprite as mentioned above.
Harriet Bazley
Michael Harding wrote:
> One of the "limited uses" I found was when I produced the parish
> magazine. I used to use TurboDrivers with the setting "Line" to
> produce photographs for publication via photocopier.
>
> The result was superb - far superior to anything I've seen produced by
> Windows machines - especially if I tweaked the contrast of photographs
> in Publisher, to suit photocopier characteristics.
Interesting effect on photographs. :-)
I suppose I'd have to try photocopying the image to get the full
impression...!
--
Harriet Bazley == Loyaulte me lie ==
Time is nature's way of making sure that everything doesn't happen at once.
Harriet Bazley
Martin Wuerthner wrote:
> In message <a0415cc64...@freeuk.com>
> Harriet Bazley <baz...@feathermail.co.uk> wrote:
[snip]
> > Lpi currently states 37.5 as per the manual.
>
> Yes, and precisely that is the problem. This is too low for the kind
> of effect you are trying to achieve. There is not a single screen
> setting that is perfect for all types of graphics. Try a setting of 75
> for a change and watch the difference! It cannot hurt to try 100 as
> well.
Oh, that definitely makes a marked result! It has the interesting
effect of increasing the contrast as well - presumably the reduced
number of shades mentioned in the manual - which is actually a good
thing in this context..
>
> > There's also a mystery option box (unticked) for 'error-diffused
> > sprites', which apparently post-dates the manual, as it isn't mentioned
> > and doesn't appear in the screenshots!
>
> That is worth trying as well since it is directly relevant for your
> situation. The technical details of this are probably not too
> important. It is higher quality in many situations, in particular for
> the kind of fuzzy drawing you have got but I doubt it will make a big
> difference. Changing the lpi setting will have a greater impact.
>
Actually, it makes quite a big difference after the lpi setting has been
changed; makes the whole thing look more 'charcoal-y' and less
'newspaper-y', if you see what I mean. The most noticeable effect is
on the flat background staining around the edges of the scan, but of
course in real life I'd have edited that out first. :-)
What it is to know properly how to use the equipment that one's got !
--
Harriet Bazley == Loyaulte me lie ==
I'm all for computer dating.... But I wouldn't want one to marry my sister.