Re: [Gimp-user] Scaling and resolution

2009-09-15 Thread Jaime Seuma
Thank you all for the tips and links, I think this is enough info to
make me understand the whole thing, and to make me feel comfortable with it.

Best regards

Jaime

David Gowers wrote:

 In GIMP (and Photoshop, and some other editing software)
 it will make it display differently. If your display reports its size
 correctly and Dot for Dot is off, the image will display at the
 correct size, closely matching the original DPI (of course you do not
 get any more actual dots out of this -- it just means that the
 relative scale of things is correct).
 
 It's easy to see this if you halve the DPI for one dimension (eg. so
 DPI == 36x72) and then turn off Dot for Dot
 
 On a 300dpi device it will
 still display as 1 1/3 in, even if you set the resolution to 70dpi.
 
 This is true for most simple 'viewing' software, which doesn't scale
 the view to be accurate. Not for editors that try to be accurate, such
 as GIMP.
 
 David
 
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[Gimp-user] Scaling and resolution

2009-09-14 Thread Mark
Jaime Seuma wrote:


See if this helps:
http://www.scantips.com/basics01.html


Thank you for making this link available.

-- 
Mark (via www.gimpusers.com)
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Re: [Gimp-user] Scaling and resolution

2009-09-14 Thread Patrick Horgan




Jaime Seuma wrote:

  Hi

This is an interesting question also to me.

David Gowers wrote:

  
  
No, if you turn off View-Dot for dot then the DPI relative to your
display DPI is used to scale your view of the image.

  
  
That much I had already found; but still, when I open a file that has
been scaled only in resolution (for instance 300-700), still the
different imageviewers display the same image.
  

A 400 pixel wide image will always have exactly 400 pixels across, so
on any given display device it will show the same irregardless of the
resolution. On a 70dpi device it will be 5.71 inches wide, on a 90dpi
device it will be 4.44 inches wide, on a 300dpi device it will be 1 1/3
in.

If you set the dpi for the image to match the device you intend to show
it on, then if, for example you change units on the bottom of the
drawing window to inches, it will accurately report to you the sizes of
things as you expect to display them.

It won't make it display any differently though. On a 300dpi device it
will still display as 1 1/3 in, even if you set the resolution to
70dpi. Hope that helps.

Patrick



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Re: [Gimp-user] Scaling and resolution

2009-09-14 Thread David Gowers
On Tue, Sep 15, 2009 at 9:40 AM, Patrick Horgan phorg...@yahoo.com wrote:
 Jaime Seuma wrote:

 Hi

 This is an interesting question also to me.

 David Gowers wrote:



 No, if you turn off View-Dot for dot then the DPI relative to your
 display DPI is used to scale your view of the image.


 That much I had already found; but still, when I open a file that has
 been scaled only in resolution (for instance 300-700), still the
 different imageviewers display the same image.


 A 400 pixel wide image will always have exactly 400 pixels across, so on any
 given display device it will show the same irregardless of the resolution.
 On a 70dpi device it will be 5.71 inches wide, on a 90dpi device it will be
 4.44 inches wide, on a 300dpi device it will be 1 1/3 in.

 If you set the dpi for the image to match the device you intend to show it
 on, then if, for example you change units on the bottom of the drawing
 window to inches, it will accurately report to you the sizes of things as
 you expect to display them.

 It won't make it display any differently though.
In GIMP (and Photoshop, and some other editing software)
it will make it display differently. If your display reports its size
correctly and Dot for Dot is off, the image will display at the
correct size, closely matching the original DPI (of course you do not
get any more actual dots out of this -- it just means that the
relative scale of things is correct).

It's easy to see this if you halve the DPI for one dimension (eg. so
DPI == 36x72) and then turn off Dot for Dot

 On a 300dpi device it will
 still display as 1 1/3 in, even if you set the resolution to 70dpi.

This is true for most simple 'viewing' software, which doesn't scale
the view to be accurate. Not for editors that try to be accurate, such
as GIMP.

David
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[Gimp-user] Scaling and resolution

2009-09-12 Thread Michael J. M.
Hello all,

I experimented with the resolution settings in the gimp -- scale image
menu.

The resolution does not seem to have any effect on the rendering of the image
on a computer screen. 

It has no effect on file size either.

I checked this by scaling and saving the same image in 3 different
resolutions
(but no other changes):

72dpi, 300dpi, 600dpi.

When opening them again all were rendered at the same size on the screen.

I concluded that the dpi setting is only used by printers.
Is this correct?

-- 
Michael J. M. (via www.gimpusers.com)
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