IrfanView: DPI settings?

  • Thread starter Thread starter Terry Pinnell
  • Start date Start date
T

Terry Pinnell

I've got myself a bit confused here. I'm looking at an image in
IrfanView. (FWIW, it's from a site explaining why the DPI concept is
meaningless for screen purposes.) It has a resolution setting of 7
dpi, as claimed by its author and as seen by me in various image
editors' print setup dialogs. And IV's Info dialog also shows 7 dpi
(and conveniently lets me change it if I wished).

So can someone please explain why in IV's Print Preview window it's
shown as 360 DPI, not 7? (And that box is not editable.)
 
Terry said:
I've got myself a bit confused here. I'm looking at an image in
IrfanView. (FWIW, it's from a site explaining why the DPI concept is
meaningless for screen purposes.) It has a resolution setting of 7
dpi, as claimed by its author and as seen by me in various image
editors' print setup dialogs. And IV's Info dialog also shows 7 dpi
(and conveniently lets me change it if I wished).

So can someone please explain why in IV's Print Preview window it's
shown as 360 DPI, not 7? (And that box is not editable.)
Click to expand...

----------
There is a relation between resolution and size of your hard copy print.
This following link explains it very well. Although it's written for
scanners, it's relevant for printers as well. It also explains the multiple
meaning of dpi and why the changing of it doesn't make any difference on a
monitor. You'll never get a print wrong again :-)
http://www.scantips.com/basics01.html
Good luck
H.N.
 
Herbert Nagler said:
----------
There is a relation between resolution and size of your hard copy print.
This following link explains it very well. Although it's written for
scanners, it's relevant for printers as well. It also explains the multiple
meaning of dpi and why the changing of it doesn't make any difference on a
monitor. You'll never get a print wrong again :-)
http://www.scantips.com/basics01.html
Good luck
H.N.
Click to expand...

Thanks, Herbert - but that's the very site I meant! I don't think it
answers my specific query about IrfanView's inconsistency. Where does
the 360 come from? I can only think that it's some sort of print
default setting?
 
Thanks, Herbert - but that's the very site I meant! I don't think it
answers my specific query about IrfanView's inconsistency. Where does
the 360 come from? I can only think that it's some sort of print
default setting?
Click to expand...
 
I'm lost! Could you elaborate please?

First, my point was that *I* can't default or specify the DPI at all,
as that seems down to IV.

Second, why do you say the preview shows it will be very small? Here
in IV I read 28.2 x 20.4 cm (for Landscape), which is a full A4 page.

Here's the actual file
http://www.terrypin.dial.pipex.com/Images/72DPI-Myth-7.jpg
and here's a screenshot of the Print Preview
http://www.terrypin.dial.pipex.com/Images/IrfanViewPrint1.jpg

BTW, I'm also puzzled why the preview is distorted, when the option
for 'Original' is set?
 
Terry said:
I'm lost! Could you elaborate please?

First, my point was that *I* can't default or specify the DPI at all,
as that seems down to IV.

Second, why do you say the preview shows it will be very small? Here
in IV I read 28.2 x 20.4 cm (for Landscape), which is a full A4 page.

Here's the actual file
http://www.terrypin.dial.pipex.com/Images/72DPI-Myth-7.jpg
and here's a screenshot of the Print Preview
http://www.terrypin.dial.pipex.com/Images/IrfanViewPrint1.jpg

BTW, I'm also puzzled why the preview is distorted, when the option
for 'Original' is set?
Click to expand...

----------------------
Terri, Irfanview is not the best client to explain the printout relations.
(I'm using PSP btw). In fact, Irfanview's print review window is misleading
and wrong in parts. But you will find, that if you resize your picture to
360 dpi, your picture will be very small in the preview screen, compared to
the 7 dpi. (And it should print out with a size of 2.907 cm x 2.286 cm, but
with the best possible quality). You can resize the dpi in IV or any other
graphics program.
If you were to print the picture in 7 dpi, it would be 149 x 117 cm, but
would have a jagged, pixelised appearance.

Irfanview actually got it wrong, as far as the print review panel is
concerned. No wonder you're confused.
The top option in the print size panel (Original size from image dpi) is
wrong. It should show you a small picture, if you have resized your pic to
360 dpi. Instead it duplicates option 3 (stretch to page, no aspect ratio).
Even option 5 (scale 1:1 x and y ) doesn't give the right display results in
the top right corner. The picture should show even smaller.
All what Irfanview does, is attempt to make your picture fit to a page, but
it is not very professional about it.
I would suggest, you use a more upmarket graphics program to trial these
size relationships.

I can now understand your frustration.
HTHH
H.N
 
Herbert Nagler said:
----------------------
Terri, Irfanview is not the best client to explain the printout relations.
(I'm using PSP btw). In fact, Irfanview's print review window is misleading
and wrong in parts. But you will find, that if you resize your picture to
360 dpi, your picture will be very small in the preview screen, compared to
the 7 dpi. (And it should print out with a size of 2.907 cm x 2.286 cm, but
with the best possible quality). You can resize the dpi in IV or any other
graphics program.
If you were to print the picture in 7 dpi, it would be 149 x 117 cm, but
would have a jagged, pixelised appearance.

Irfanview actually got it wrong, as far as the print review panel is
concerned. No wonder you're confused.
The top option in the print size panel (Original size from image dpi) is
wrong. It should show you a small picture, if you have resized your pic to
360 dpi. Instead it duplicates option 3 (stretch to page, no aspect ratio).
Even option 5 (scale 1:1 x and y ) doesn't give the right display results in
the top right corner. The picture should show even smaller.
All what Irfanview does, is attempt to make your picture fit to a page, but
it is not very professional about it.
I would suggest, you use a more upmarket graphics program to trial these
size relationships.

I can now understand your frustration.
HTHH
H.N
Click to expand...

Thanks a lot, Herbert, it's now very much clearer to me. I'll try a
few more practical experiments to drive it home.

I too use 'PSP' - but that's PaintShop Pro in my case! I'm guessing
you use PhotoShop Pro?
 
Terry said:
Thanks a lot, Herbert, it's now very much clearer to me. I'll try a
few more practical experiments to drive it home.

I too use 'PSP' - but that's PaintShop Pro in my case! I'm guessing
you use PhotoShop Pro?
Click to expand...
--------------------------
Paint Shop Pro (7) as well :-)
I always use [File > Print multiple images] for my prints, even with single
images, so I can have a grid.
Irfanview is a very good and fast image viewer, and it's my default viewer
for its speed, but for printing it lacks the goods, unless one is happy with
a general "stretched" print.

cheers,
H.N.
 
KeithS said:
Thank you Herbert, for the first time I got it right first time
(IYSMIM) Thanks :)
KeithS
Click to expand...

---------------
Hello Keith :-)
Thanks for the feedback !
I'm still wondering, what IYSMIM might stand for ?

Cheers
H.N.
 
They left of the 'U' (IYSMIMU), If You See Me In My Underwear.
--
Wayne Boatwright *¿*
____________________________________________

Give me a smart idiot over a stupid genius any day.
Sam Goldwyn, 1882-1974


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Thanks, Herbert - but that's the very site I meant! I don't think it
answers my specific query about IrfanView's inconsistency. Where does
the 360 come from? I can only think that it's some sort of print
default setting?
Click to expand...

Correct. It will be the default setting for the printer.
 
On Wed, 06 Jul 2005 09:36:35 +0100, Terry Pinnell

[snip]
Thanks, Herbert - but that's the very site I meant! I don't think it
answers my specific query about IrfanView's inconsistency. Where does
the 360 come from? I can only think that it's some sort of print
default setting?
Click to expand...

It comes from the printer driver. If you have several diferent printer
drivers on your system, change the printer and the DPI will change.

On my old Canon 4310, it comes up as 360, while on my Canon Pixma IP4000
it coes up as zero, and on a pdf "printer" it comes up as 600.

Cheers, Allan
 
Allan Mikkelsen said:
On Wed, 06 Jul 2005 09:36:35 +0100, Terry Pinnell

[snip]
Thanks, Herbert - but that's the very site I meant! I don't think it
answers my specific query about IrfanView's inconsistency. Where does
the 360 come from? I can only think that it's some sort of print
default setting?
Click to expand...

It comes from the printer driver. If you have several diferent printer
drivers on your system, change the printer and the DPI will change.

On my old Canon 4310, it comes up as 360, while on my Canon Pixma IP4000
it coes up as zero, and on a pdf "printer" it comes up as 600.
Click to expand...
David, Allan: Thanks both.
 
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