 |
|
|
|
|
|
| |
| |
|
|
|
|
| |
| |
|
|
I use Moray for Windows with POV-Ray 3.01 to do 3d prints. I was
wondering if there was a way to increase the dpi settings in the
renderer, to reflect the dpi of my printer? I've not been able to do
this.
Wayne Earl
wea### [at] jps net
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
| |
|
|
Wayne Earl wrote:
>
> I use Moray for Windows with POV-Ray 3.01 to do 3d prints. I was
> wondering if there was a way to increase the dpi settings in the
> renderer, to reflect the dpi of my printer? I've not been able to do
> this.
This is a bit odd question. As far as i know dpi is never saved in the
targa-file that povray gives as result of a rendering.
Although the confusion is understandable.
DPI means dots per inch. For a standard monitor the value is 75. If you
print a 800*600 image that takes a full screen it wil only take a few
inches on a 300dpi printer. It will only be smaller on paper than is on
the screen. but thats' all.
There is no need to set this value, just make a large enough image and
use a decent graphics-program to print this image. It will definitaly
look well.
--
Peter O
---------------------------------------------------------------
no-### [at] kotnetorg
You're nobody until somebody loves you. (James Dean)
---------------------------------------------------------------
http://www.gv.kotnet.org/~nbody
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
| |
|
|
Wayne Earl wrote:
>I use Moray for Windows with POV-Ray 3.01 to do 3d prints. I was
>wondering if there was a way to increase the dpi settings in the
>renderer, to reflect the dpi of my printer? I've not been able to do
>this.
There is no way to increase the resolution for rendering. But you can
increase it after its done. I've done a couple of images that have gone to
print which need a resolution of 304.8 pixels per inch or 120 pixels per cm.
The one thing you will need is a program such as Photoshop that can change
the resolution of images. So before you start your rendering you will need
to make a dummy file in Photoshop at the size and resolution you will want
it to be. Then you can change the resolution to 72 pixels per inch and your
image size will increase. He is an example, let's say I want a final image
with 304.8 pixels per inch and the size to be 4x5 inches. You will make this
file in Photoshop and then change the resolution to 72 pixels per inch and
the size then goes up to 16.931x21.167 or 1219 x 1524 pixels. Now you can
use that size 1219x1524 to render to and when your done bring it into
Photoshop or any other paint program that can work with resolution and take
it up to 304.8 pixels per inch and the size will drop to 4x5 inches. If any
one has any other ways of doing this it would be interesting to know. Hope
this helps.
Glen
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
| |
|
|
Glen Adomovicz wrote in message <6i78t7$a8m$1@oz.aussie.org>...
>
>He is an example, let's say I want a final image
>with 304.8 pixels per inch and the size to be 4x5 inches. You will make
this
>file in Photoshop and then change the resolution to 72 pixels per inch and
>the size then goes up to 16.931x21.167 or 1219 x 1524 pixels.
The question is, why use Photoshop for the simple calculation, that 304.8
pixels * 4 equals 1219 pixels and 304.8 pixels * 5 equals 1524 pixels? I
would say that a simple calculator does the job ;-)
No really, this question (or a similar one) pops up on this or other groups
frequently, but:
DPI is an output-device unit. Images (that is, pixel-rasters) don't have any
DPI size themselfs, they are just a bunch of colored squares arranged in a
checkerboard like fashion!
And even formats (like TIFF) that "support" DPI don't *really* support DPI:
A TIFF stores the "intended" or "preferred" DPI size of the image as a
convenience, so that when you load the image in some other program (for
example in Word, where you paste it into your text), you don't need to
specify how large you want the image to be.
So if you scan an image with a certain number of DPIs and save it as a TIFF,
the number of DPIs is stored with the image, _to your convenience_!. When
you then paste the image into a Word-doc (without resizing it) and print the
Word-doc, the image will have the same physical size as it had on the
original.
Very neat, but that doesn't give the bunch of pixels that actually compose
the image any DPI-releated property. The DPI related property was simply
stored at some other place in the file, where Word knew how to read it. Sort
of like a TGA (that does not store any DPI infos) saved to a floppy with a
Post-It sticker attached where you write down: "I scanned this image with
X.. DPI".
Even the often used 72 or 75 DPIs for monitors are actually rubbish: A 21''
monitor showing 640x400 pixels VGA would have (very roughly with pythagoras)
38 DPI, while a 15'' monitor showing 1024x768 pixels would have about 85.3
DPI.
It is quite simple:
If you have an image of 600x600 pixels and print it with 600dpi, then it
will be 1x1 inch large. If you print the same image with 300dpi you get a
2x2 inches image etc.
So you only need to know the final print-size (in DPI) and how large the
image is to be on the paper (in inches). Then you simply render an image
that has enough pixels to fullfill that: If your image is printed with
300dpi and is to cover an area of 5x4 inches on the paper, than you simply
render an image with (5x300) x (4x300) = 1500 x 1200 pixels.
Johannes.
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
| |
|
|
Johannes Hubert wrote:
>The question is, why use Photoshop for the simple calculation, that 304.8
>pixels * 4 equals 1219 pixels and 304.8 pixels * 5 equals 1524 pixels? I
>would say that a simple calculator does the job ;-)
Johannes,
Thanks for the input, I new there had to be a better way.
Glen
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
| |
|
|
Actually, all who replied had the entire thing all wrong. Sorry - but true!
I say this from more than 10 years of experience with computer programs & 16
years as a professional artist.
You don't need any more than half (at the max) of your printer resolution to
obtain a quality print. This is more than adequate to meet ANY printing
needs. Any more than that is overkill & only creates a file that uses up
uncessary file storage space.
Fore example - if you are printing to an inkjet printer with 720 dpi, you need
not go more than 360dpi output to obtain the best quality print that your
printer can produce. Even this is more than enough. You can even go as low
as 1/3 of your printer's output dpi and be safe that you are getting the best
possible output.
If you plan ahead & know your final printed image size - you can
mathematically figure out what your final image size should be. For example -
if your image needs to be 4" wide by 3" tall, you can set your render settings
to no more than 800x600. If your image needs to be printed at 8" wide by 10"
tall - you would set your render settings to 1600x2000.
You can verify this in any "Photoshop" How-To book at your local book store.
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
| |
|
|
Tony Vigil wrote in message <354AD5A1.4F0BBE00@gte.net>...
>Actually, all who replied had the entire thing all wrong. Sorry - but
true!
I always like these "You are all wrong!" replies :-)
>I say this from more than 10 years of experience with computer programs
What, only 10 years? You surely did start late, did you? (Help, don't flame
me, that was supposed to be a joke!)
Actually, everything you write in your mail after that is possibly very
correct and I am not going to dispute it, but:
Nothing what you write proves anything of my stuff wrong, so I don't
understand your first line "everything is wrong".
What you say is essentially, that you don't need to use the full DPI the
printer is capable of, to still get the fullest quality. Nothing against
that, it might be true. But the theory is still: If you want to print with X
DPI and your image is to be Y inces in size, then you need to create a
source-image with X*Y pixels. And it was that "theory" that I explained in
my post, because of the very common misconception about images "having" a
DPI value.
And to this you added the valuable advice that, while theory says you need
X*Y pixels, in real life (X*Y)/2 are still enough to get full quality.
Very well, only please don't say anything like "all who replied had the
entire thing all wrong" without backing that up - and you definitely didn't!
Johannes.
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
| |
|
|
Johannes,
I am sorry if I sounded a bit harsh. My bad!
I should have qualified which information was incorrect.
In one paragraph, you wrote:
"It is quite simple:
If you have an image of 600x600 pixels and print it with 600dpi, then it
will be 1x1 inch large. If you print the same image with 300dpi you get a
2x2 inches image etc."
This is sort of correct. Yes, you certainly could print the 600dpi image at
1"x1". You could also get the same or better quality print from the same 600dpi
image at 2"x2" or even 4"x4" on some inkjet printers. "Dots per inch" and
"pixels per inch" are two entirely different things. One has to do with
printing, and the other has to do with video display.
In your example - if the 600x600 image was saved as a tiff at 600 pixels per
inch in any commercial image editor (i.e. Photoshop or CorelPaint), The image
will most certainly be printed 1x1 inch from within that program. Unless of
course, your printer allows you to print at a different enlargment. If that
same image is placed in Illustrator or Freehand or someother graphic
application, you have the ability to change the size of the image. The number
of available pixels doesn't change, but the effective dpi does. The same 1"
square 600x600 image enlarged to 2"x2" will now have an effective dpi of 300.
One thing I did mention in my original response was this - all the information
that I provided can be found in any 3rd party book about Photoshop or Computer
Imaging for press.
Again, I am sorry if I bit down too hard.
Sincerely,
Tony Vigil
Carta.graffiti
Johannes Hubert wrote:
> Tony Vigil wrote in message <354AD5A1.4F0BBE00@gte.net>...
> >Actually, all who replied had the entire thing all wrong. Sorry - but
> true!
>
> I always like these "You are all wrong!" replies :-)
>
> >I say this from more than 10 years of experience with computer programs
>
> What, only 10 years? You surely did start late, did you? (Help, don't flame
> me, that was supposed to be a joke!)
>
> Actually, everything you write in your mail after that is possibly very
> correct and I am not going to dispute it, but:
> Nothing what you write proves anything of my stuff wrong, so I don't
> understand your first line "everything is wrong".
>
> What you say is essentially, that you don't need to use the full DPI the
> printer is capable of, to still get the fullest quality. Nothing against
> that, it might be true. But the theory is still: If you want to print with X
> DPI and your image is to be Y inces in size, then you need to create a
> source-image with X*Y pixels. And it was that "theory" that I explained in
> my post, because of the very common misconception about images "having" a
> DPI value.
>
> And to this you added the valuable advice that, while theory says you need
> X*Y pixels, in real life (X*Y)/2 are still enough to get full quality.
> Very well, only please don't say anything like "all who replied had the
> entire thing all wrong" without backing that up - and you definitely didn't!
>
> Johannes.
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
| |
|
|
Hi Tony,
I think we more or less say the same things with different words.
And while I tried to explain in an abstract way why images as such don't
have any DPI size (and why it is therefor futile to ask POV-Ray to render a
certain DPI size), I did not discuss anything concerning the quality of the
printed output. It is difficult enough to explain the very messed up concept
of screen-resoultion and printing-resolution in a simple news-group post so
I didn't want to start into explaining why a 600x600 pixel image looks
better when printed on a 2x2 inch area (300DPI) than on a 1x1 inc area
(600DPI). For that I would have to start explaining how color-printers work,
how they mix their colors etc.
In the light of the original post it was probably a good idea of you to add
the quality-concerned view of the problem.
Tony Vigil wrote in message <354CC40F.3F47F503@gte.net>...
>I am sorry if I sounded a bit harsh. My bad!
Apology accepted, though I didn't really feel the need to get one :-) I
wasn't that pissed... (you can always tell I'm not, when I litter my
postings with smileys... :-))
Johannes.
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
| |
|
|
On Mon, 4 May 1998 09:20:17 +0200, "Johannes Hubert"
<jhu### [at] algonetse> wrote:
>Hi Tony,
Hi Joh! You are all wrong! Please, don't beat me!
But I beat the drum, next TreeDesigner will have an L-system inbuilt!
That's amazing news!
>
>I think we more or less say the same things with different words.
>
>And while I tried to explain in an abstract way why images as such don't
>have any DPI size (and why it is therefor futile to ask POV-Ray to render a
>certain DPI size), I did not discuss anything concerning the quality of the
>printed output. It is difficult enough to explain the very messed up concept
>of screen-resoultion and printing-resolution in a simple news-group post so
>I didn't want to start into explaining why a 600x600 pixel image looks
>better when printed on a 2x2 inch area (300DPI) than on a 1x1 inc area
>(600DPI). For that I would have to start explaining how color-printers work,
>how they mix their colors etc.
Here we go! And there comes in the LPI, that's lines per inch, and
that's the value for the printer, how many colors he can actually mix
at the available dpi.
>
>In the light of the original post it was probably a good idea of you to add
>the quality-concerned view of the problem.
And that's what he meant there, correct me, if I am wrong, Tony.
On a bubblejet printer, the effect of the rasterized print is achieved
by smaller or bigger points of the color 'bubbled'. Now, if one would
print a 24bit color image delivered to the printer at its maximum
resolution, the space available between the dots would only allow
for no shading or, with a bad printer driver that does not care, a
waste of ink, as there would not be any distinguishable image, just a
sea of ink. So what the windows driver does, for instance, he
calculates down, I do not now to how many lpi the given bitmap as per
the user settings, contrast prefered, saturation prefered etc.
Some years ago a 360dpi bublejet at a setting of the maximum 100 lpi
could deliver 9 shades of one color. So that would make a realworld
3bit COLOR resolution print. At a setting of 60 lpi this increased to
25 shades, which made 4 and a half bits and so forth. Now, it is
clear, there can be different methods for a driver, to treat the given
input resolution to meet the given demand for quality. He could blow
up, lets say a 800x600pixel input bitmap to a 3200x2400 dots print and
has 3 of 4 dots as space for dot variation available, he really
overprints his dots then also, compared to a thin b/w print. He
divides his print resolution compared to the b/w print the same time
by for, this would be a 80 lpi print for a 360 dpi printer. For a 1440
dpi printer, it would be a 360 lpi color print, I don't think, they do
this, they will give more space, which will give a higher color
resolution.
So, I have not checked them really out, but take a 21" monitor
at a screen resolution of 1024x768, has ~60 pixels/inch. With the
modern 1440 dpi color printers, if they really do not call some
dithering method resolution, and as the color resolution roughly
quadruples with halfing the lpi resolution, a ~1 to 1 pixel/dot print,
would give (60 lpi) a color print of 225 shades of one color, 7 three
quarter bits, almost true color.
Don't ask me, how they call it, enlargement or whatever, but that's
what the driver and printer have to do to master color print.
I know other platforms, where ordinary printer drivers let set you lpi
directly, but that's another thread.
Of course, there are also different dithering methods involved,
even the raster angle, but that's to much now. And, of course, you
know it anyway, Johannes.
Just bounced into the thread last.
>Tony Vigil wrote in message <354CC40F.3F47F503@gte.net>...
>>I am sorry if I sounded a bit harsh. My bad!
>
>
>Apology accepted, though I didn't really feel the need to get one :-) I
>wasn't that pissed... (you can always tell I'm not, when I litter my
>postings with smileys... :-))
>
>Johannes.
>
>
Hei! Wanted to make my first smiley ever, now my Free Agent shows it
blue!
:-))
,
,:-)), aha!
steff
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
|
|
