Is there a way to specify the resolution of the images created by
POV-RAY?  I have created a couple of molecular graphics which look great
on screen but when they are printed, they contain jaggies even though
they were antialiazed.

Furthermore, when I open the TGA file in xv (or any other graphics
program) it says the resolution is 72dpi.  I would like this to be at
least 600dpi.  Is there a way to specify this in POV-Ray?

Any help is appreciated.

Mike


--
*******************************
Michael DiDonato, PhD
The Scripps Research Institute
Department of Molecular Biology
Maildrop MB4
10550 North Torrey Pines Road
La Jolla, CA, 92037

Tel: (858) 784-9261
FAX: (858) 784-2277
*******************************

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Michael DiDonato wrote:
> 
> Is there a way to specify the resolution of the images created by POV-RAY?  I have
created a couple of molecular graphics
> which look great on screen but when they are printed, they contain jaggies even
though they were antialiazed.
> 
> Furthermore, when I open the TGA file in xv (or any other graphics program) it says
the resolution is 72dpi.  I would like
> this to be at least 600dpi.  Is there a way to specify this in POV-Ray?

To the best of my knowledge POV-Ray has no facilityfor specifying the
the dpi saved in the image. However I see no reason why you couldn't
open the image in your favorite graphics program and resave it at a
higher dpi level.

-- 
Ken Tyler - 1400+ POV-Ray, Graphics, 3D Rendering, and Raytracing Links:
http://home.pacbell.net/tylereng/index.html http://www.povray.org/links/

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Yes, all you must do is render at a very large number of pixels, and use an
image editor and resave it at a heigher res. If you do not have an editor
that can do this and you are using MacOS then I would recomend
GraphicsConverter, which you can get from www.macdownload.com.
______
David McCabe
dav### [at] maccom
http://homepage.mac.com/davidmccabe/index.htm
Jesus loves you! 


>> Is there a way to specify the resolution of the images created by POV-RAY?  I
>> have created a couple of molecular graphics
>> which look great on screen but when they are printed, they contain jaggies
>> even though they were antialiazed.
>> 
>> Furthermore, when I open the TGA file in xv (or any other graphics program)
>> it says the resolution is 72dpi.  I would like
>> this to be at least 600dpi.  Is there a way to specify this in POV-Ray?
> 
> To the best of my knowledge POV-Ray has no facilityfor specifying the
> the dpi saved in the image. However I see no reason why you couldn't
> open the image in your favorite graphics program and resave it at a
> higher dpi level.

Post a reply to this message

Ken wrote:
> 
> > Furthermore, when I open the TGA file in xv (or any other graphics program) it
says the resolution is 72dpi.  I would like
> > this to be at least 600dpi.  Is there a way to specify this in POV-Ray?
> 
> To the best of my knowledge POV-Ray has no facilityfor specifying the
> the dpi saved in the image. However I see no reason why you couldn't
> open the image in your favorite graphics program and resave it at a
> higher dpi level.
> 

AFAIK the TGA file header does not contain any dpi information.

Christoph

-- 
Christoph Hormann <chr### [at] gmxde>
Homepage: http://www.schunter.etc.tu-bs.de/~chris/

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In article <3A105C74.B558AA0F@scripps.edu>, "Michael DiDonato"
<did### [at] scrippsedu> wrote:
> Is there a way to specify the resolution of the images created by
> POV-RAY?  I have created a couple of molecular graphics which look great
> on screen but when they are printed, they contain jaggies even though
> they were antialiazed.

  I think the printer is more at fault then the image at that point..

> Furthermore, when I open the TGA file in xv (or any other graphics
> program) it says the resolution is 72dpi.  I would like this to be at
> least 600dpi.  Is there a way to specify this in POV-Ray?

  DPI is really a *bad* term.  You see, where is there a reference to an
'inch' in a digital image?  I'd imaging that xv is figuring out the size
of the image, compared to the size of your screen.  I mean think about
it..  Do my images magically have a higher DPI when displayed on a higher
resolution monitor?

> Any help is appreciated.

  What application are you using the print these images?  What printing
system are you going thru?  And best of all, what printer are you using?
Remember, just becouse a printer can print at 600 DPI doesn't mean the
application is giving it information at this level..

  DPI is simply the number of pixels in one inch.

Post a reply to this message

I know its the printing step that is the culprit, but I don't know how to fix
it.  I printed some images from xv and they look like crap compared to what I
see on the screen.  AFAIK screen resolution is always 72 dpi regardless of
how big the monitor is.

Mike


Thomas Charron wrote:

> In article <3A105C74.B558AA0F@scripps.edu>, "Michael DiDonato"
> <did### [at] scrippsedu> wrote:
> > Is there a way to specify the resolution of the images created by
> > POV-RAY?  I have created a couple of molecular graphics which look great
> > on screen but when they are printed, they contain jaggies even though
> > they were antialiazed.
>
>   I think the printer is more at fault then the image at that point..
>
> > Furthermore, when I open the TGA file in xv (or any other graphics
> > program) it says the resolution is 72dpi.  I would like this to be at
> > least 600dpi.  Is there a way to specify this in POV-Ray?
>
>   DPI is really a *bad* term.  You see, where is there a reference to an
> 'inch' in a digital image?  I'd imaging that xv is figuring out the size
> of the image, compared to the size of your screen.  I mean think about
> it..  Do my images magically have a higher DPI when displayed on a higher
> resolution monitor?
>
> > Any help is appreciated.
>
>   What application are you using the print these images?  What printing
> system are you going thru?  And best of all, what printer are you using?
> Remember, just becouse a printer can print at 600 DPI doesn't mean the
> application is giving it information at this level..
>
>   DPI is simply the number of pixels in one inch.

--
*******************************
Michael DiDonato, PhD
The Scripps Research Institute
Department of Molecular Biology
Maildrop MB4
10550 North Torrey Pines Road
La Jolla, CA, 92037

Tel: (858) 784-9261
FAX: (858) 784-2277
*******************************

Post a reply to this message

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My world is currently PC-based (Windows 98/NT) so this may not apply to
you...

If you generate an image that is 1000x1000 pixels and print it as a 2"x2"
square you will have 500dpi.

If you print the same image as a 4"x4" square you will have 250dpi... and it
will look worse.

Most screens average about 72dpi, but in Windows you can adjust your screen
resolution.  For example if you set your resolution to 1280x1024 and view
the image you will see a certain dpi, and if you subsequently change your
resolution to 800x600 you will see approximately 2/3 the dpi... and it will
look worse.

In general I think you want to print at 300 dpi or better to have a good
image.  Generate a big picture and print it in a small square to achieve
adequate resolution.

I use Paint Shop Pro for general graphics operations like this.  Sorry I
don't know of a comparable unix or mac program, but I'm sure they exist.

"Michael DiDonato" <did### [at] scrippsedu> wrote in message
news:3A107956.CA89EB0E@scripps.edu...
I know its the printing step that is the culprit, but I don't know how to
fix it.  I printed some images from xv and they look like crap compared to
what I see on the screen.  AFAIK screen resolution is always 72 dpi
regardless of how big the monitor is.
Mike

Post a reply to this message

I don't printout anything that is less than 3200x2400 res if I'm looking 
for quality prints. Printing in Linux is not the way to go as most 
printer drivers with advanced options are not written for Linux. I could 
not get my printer to print very well in Linux but in W98 it's just 
great (Epson Photo 1200). That is just what I have seen but your printer 
may differ. 
  Michael DiDonato wrote in message <3A105C74.B558AA0F@scripps.edu>...
  Is there a way to specify the resolution of the images created by 
POV-RAY?  I have created a couple of molecular graphics which look great 
on screen but when they are printed, they contain jaggies even though 
they were antialiazed. 
  Furthermore, when I open the TGA file in xv (or any other graphics 
program) it says the resolution is 72dpi.  I would like this to be at 
least 600dpi.  Is there a way to specify this in POV-Ray? 

  Any help is appreciated. 

  Mike 
    

-- 
*******************************
Michael DiDonato, PhD
The Scripps Research Institute
Department of Molecular Biology 
Maildrop MB4
10550 North Torrey Pines Road
La Jolla, CA, 92037

Tel: (858) 784-9261
FAX: (858) 784-2277
*******************************

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Michael DiDonato wrote:
> 
> Is there a way to specify the resolution of the images created by
> POV-RAY?  I have created a couple of molecular graphics which look
> great on screen but when they are printed, they contain jaggies even
> though they were antialiazed.

> Furthermore, when I open the TGA file in xv (or any other graphics
> program) it says the resolution is 72dpi.  I would like this to be at
> least 600dpi.  Is there a way to specify this in POV-Ray?

	You simply control the size of the POV image so you have 600 pixels to
print at that resolution. For example, create 800x600 for a 1.333x1 inch
image. 

	That last time I tried something like that was on a much slower machine
and it ate up most of the processing doing the size conversion for an HP
560C. 

-- 
Want to know how Palestinians feel? Imagine if Israel
had been declared in your country. 
	-- The Iron Webmaster, 275

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Thomas Charron wrote:

>   I think the printer is more at fault then the image at that point..

It's a sort of moire between the printer's diffusion and the image's
resolution, I think. I get it when I try to print normal size
(640x480~1600x1200) images blown up to one page.

--
David Fontaine  <dav### [at] faricynet>  ICQ 55354965
My raytracing gallery:  http://davidf.faricy.net/

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I don't understand this.
  AFAIK the dpi value in an image format (if the format supports it) is
just a value. It doesn't affect anything. The image will still have the same
amount of pixels and wouldn't care less about some value in its header
called "dpi".
  If you want to change that dpi value, then just open the file with a
paint program and change that dpi value. What's the problem? If that value
has some effect when printing then it may be relevant, but it's completely
irrelevant with respect to the image file itself.
  If you want more accuracy, render your image with more pixels.

-- 
main(i,_){for(_?--i,main(i+2,"FhhQHFIJD|FQTITFN]zRFHhhTBFHhhTBFysdB"[i]
):_;i&&_>1;printf("%s",_-70?_&1?"[]":" ":(_=0,"\n")),_/=2);} /*- Warp -*/

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I have been printing some images recently and can give you some direction.
First, the printer resolution is going to be much higher than your monitor.
For example my 19 inch monitor is actually about 14 inches side-to-side and
is currently at a resolution of 1024 across.  This works out to about 73
pixels per inch.  My printer on the other hand prints at 720 dots per inch.
If I print an image that is fine "screen wise" it will be quite pixelly
printed full page on the printer.  In order to get printable images you have
to increase the render size.  I have gotten some images printed that are 34
inches wide by 25 inches tall without ANY pixels being apparent.  (Not on my
printer though, I go to a printing service.) The image size to make that
happen though is 10240 by 7680 (not a typo) so it is an order of 100 times
larger to make a clean printout.  You might get away with half that size
depending on the final size of the printout.

Of course that also means it takes *FOREVER* to render...


"Michael DiDonato" <did### [at] scrippsedu> wrote in message
news:3A105C74.B558AA0F@scripps.edu...
Is there a way to specify the resolution of the images created by POV-RAY?
I have created a couple of molecular graphics which look great on screen but
when they are printed, they contain jaggies even though they were
antialiazed.
Furthermore, when I open the TGA file in xv (or any other graphics program)
it says the resolution is 72dpi.  I would like this to be at least 600dpi.
Is there a way to specify this in POV-Ray?
Any help is appreciated.
Mike

--
*******************************
Michael DiDonato, PhD
The Scripps Research Institute
Department of Molecular Biology
Maildrop MB4
10550 North Torrey Pines Road
La Jolla, CA, 92037

Tel: (858) 784-9261
FAX: (858) 784-2277
*******************************

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Often, HTML code is disliked in newsgroups.
______
David McCabe
dav### [at] maccom
http://homepage.mac.com/davidmccabe/index.htm
God is good!

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In article <B63828CB.2CC9%dav### [at] maccom>, David 
<dav### [at] maccom> wrote:

> Often, HTML code is disliked in newsgroups.

Especially on these groups, where many people don't use newsreaders 
which support HTML and where the posts are kept as long as possible(HTML 
posts take more space).
However, Warp's message didn't use HTML, neither did any of the other 
messages in this thread...so what made you post this?

-- 
Christopher James Huff
Personal: chr### [at] maccom, http://homepage.mac.com/chrishuff/
TAG: chr### [at] tagpovrayorg, http://tag.povray.org/

<><

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On Wed, 15 Nov 2000 15:37:24 -0500, Chris Huff wrote:
>However, Warp's message didn't use HTML, neither did any of the other 
>messages in this thread...so what made you post this?

Probably Warp's signature. :)

-- 
Ron Parker   http://www2.fwi.com/~parkerr/traces.html
My opinions.  Mine.  Not anyone else's.

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Mine was sorry guys.
Chris Huff wrote in message ...
>In article <B63828CB.2CC9%dav### [at] maccom>, David
><dav### [at] maccom> wrote:
>
>> Often, HTML code is disliked in newsgroups.
>
>Especially on these groups, where many people don't use newsreaders
>which support HTML and where the posts are kept as long as possible(HTML
>posts take more space).
>However, Warp's message didn't use HTML, neither did any of the other
>messages in this thread...so what made you post this?
>
>--
>Christopher James Huff
>Personal: chr### [at] maccom, http://homepage.mac.com/chrishuff/
>TAG: chr### [at] tagpovrayorg, http://tag.povray.org/
>
><><

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In povray.general Ron Parker <ron### [at] povrayorg> wrote:
: Probably Warp's signature. :)

  My signature called HTML?!!!
  That's the worst offence anyone has ever said to me!!!

  ;)

-- 
main(i,_){for(_?--i,main(i+2,"FhhQHFIJD|FQTITFN]zRFHhhTBFHhhTBFysdB"[i]
):_;i&&_>1;printf("%s",_-70?_&1?"[]":" ":(_=0,"\n")),_/=2);} /*- Warp -*/

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Warp wrote:
> 
> In povray.general Ron Parker <ron### [at] povrayorg> wrote:
> : Probably Warp's signature. :)
> 
>   My signature called HTML?!!!
>   That's the worst offence anyone has ever said to me!!!

Looks like binary code to me. It sure isn't human readable :)

-- 
Ken Tyler - 1400+ POV-Ray, Graphics, 3D Rendering, and Raytracing Links:
http://home.pacbell.net/tylereng/index.html http://www.povray.org/links/

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On Thu, 16 Nov 2000 03:41:11 -0800, Ken wrote...
> >   My signature called HTML?!!!
> >   That's the worst offence anyone has ever said to me!!!
> 
> Looks like binary code to me. It sure isn't human readable :)

So you'd have no trouble reading it then? ;)

Or don't you have the appropriate parser installed on your AI yet?

Bye for now,
     Jamie.

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Jamie Davison wrote:
> 
> On Thu, 16 Nov 2000 03:41:11 -0800, Ken wrote...
> > >   My signature called HTML?!!!
> > >   That's the worst offence anyone has ever said to me!!!
> >
> > Looks like binary code to me. It sure isn't human readable :)
> 
> So you'd have no trouble reading it then? ;)
> 
> Or don't you have the appropriate parser installed on your AI yet?

It does not compute!

-- 
Ken Tyler - 1400+ POV-Ray, Graphics, 3D Rendering, and Raytracing Links:
http://home.pacbell.net/tylereng/index.html http://www.povray.org/links/

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Michael DiDonato a écrit :
> 
> Is there a way to specify the resolution of the images created by
> POV-RAY?  I have created a couple of molecular graphics which look
> great on screen but when they are printed, they contain jaggies even
> though they were antialiazed.
> 
> Furthermore, when I open the TGA file in xv (or any other graphics
> program) it says the resolution is 72dpi.  I would like this to be at
> least 600dpi.  Is there a way to specify this in POV-Ray?
> 
> Any help is appreciated.
> 
> Mike

	I get nice results when I render with 1/3 the number of pixels compared
to the dots on the printer. Usually an image that looks good at 100
pixels per inch on the screen will be nice at 300 dpi on the printer and
about the same size. But of course you may like it better at 600 or even
1200 dpi : then it will be respectively twice and four times smaller. So
you'll need two or four times as many pixels to get the same size as it
was at 300 dpi.

	I use The Gimp to post-process my images : that's a lot to learn but it
beats the crap of anything else on Linux. Among other things you'll find
out how many pixels an inch you have right now, accounting for you
resolution and monitor size.

	Have fun.

	Jean M.

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> I know its the printing step that is the culprit, but I don't know how to fix it.  I
printed some images from xv and they look like crap compared to what I see on the
screen.  AFAIK screen
> resolution is always 72 dpi regardless of how big the monitor is.

	DON'T USE XV to print since it produces crapped ps files
when the image is big (from my experience, don't know why).
	Use The Gimp or other image manipulation system.


*** Nicolas Calimet
*** http://pov4grasp.free.fr

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Nicolas Calimet <pov### [at] freefr> writes:

> > I know its the printing step that is the culprit, but I don't know how 
> > to fix it.  I printed some images from xv and they look like crap 
> > compared to what I see on the screen.  AFAIK screen
> > resolution is always 72 dpi regardless of how big the monitor is.
> 
> 	DON'T USE XV to print since it produces crapped ps files
> when the image is big (from my experience, don't know why).

My interpretation of the behaviour of xv is that it resizes the image in
such a way that it fits on the screen. This limits the resolution (in terms
of pixels) to the resolution of the screen.

> 	Use The Gimp or other image manipulation system.

I second this.

Thomas

-- 
http://www.thomas.willhalm.de/ (includes pgp key)

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> >[Warp]
> >   My signature called HTML?!!!
> >   That's the worst offence anyone has ever said to me!!!
> 
> Looks like binary code to me. It sure isn't human readable :)

	You should compile his nice C source code and see the
result, which is expected from a signature code... I still have
trouble (after more than one year I first time saw Warp's msgs)
to understand how it works. Warp, did you participate to this kind
of "most infamous C code" contest or something like that ?


*** Nicolas Calimet
*** http://pov4grasp.free.fr

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Nicolas Calimet <pov### [at] freefr> wrote:
:> Looks like binary code to me. It sure isn't human readable :)

  Well, this is actually true. The string in the code is binary data
(basically a bitmap) with an offset so that the values are shifted to
printable characters (kind of same type of thing as uuencode or mimencode do,
but more simple).

: Warp, did you participate to this kind
: of "most infamous C code" contest or something like that ?

  I have participated in the IOCCC but have no big expectations (the results
are very late this year). The quality of the competition is too high for
me (much like in the IRTC).

-- 
main(i,_){for(_?--i,main(i+2,"FhhQHFIJD|FQTITFN]zRFHhhTBFHhhTBFysdB"[i]
):_;i&&_>1;printf("%s",_-70?_&1?"[]":" ":(_=0,"\n")),_/=2);} /*- Warp -*/

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On Tue, 14 Nov 2000 13:22:40 +0100, Nicolas Calimet wrote:
>
>> I know its the printing step that is the culprit, but I don't know
>> how to fix it. I printed some images from xv and they look like crap
>> compared to what I see on the screen. AFAIK screen resolution is
>> always 72 dpi regardless of how big the monitor is.
>
> DON'T USE XV to print since it produces crapped ps files when the
>image is big (from my experience, don't know why).

You have to check the "save at original size" box when saving to
postscript. Otherwise the image is saved at the same size as it is
displayed (which is limited by your screen size). I have successfully
converted 3200x2400 pixel pictures to postscript with xv (which
nicely fills an A4 page at 300 dpi).

	hp

-- 
   _  | Peter J. Holzer    | Perl ist der geglückte Versuch, einen
|_|_) | Sysadmin WSR       | braindump direkt ausführbar zu machen.
| |   | hjp### [at] wsracat      |    -- Lutz Donnerhacke in dasr.
__/   | http://www.hjp.at/ |

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