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(pixle per inch) ppi is only 72 HELP



 
 
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  #1  
Old December 20th 04, 07:40 PM
Ian Hurst (Troyka)
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Default (pixle per inch) ppi is only 72 HELP


hi i use paint shop pro quite often and have recently noticed the
(pixel per inch) ppi is only 72 on every photo i have taken with my
a80. anyone know why? is it the software reducing ppi?

thanks


Ian

------------
My Photo album
http://public.fotki.com/hurst/
comments welcome
  #2  
Old December 20th 04, 08:05 PM
dylan
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The ppi (pixels per inch) is simply related to printing, it sets the size of
the print. It makes no difference to your image.

When you print just set the size you want in page setup.


"Ian Hurst (Troyka)" wrote in message
...

hi i use paint shop pro quite often and have recently noticed the
(pixel per inch) ppi is only 72 on every photo i have taken with my
a80. anyone know why? is it the software reducing ppi?

thanks


Ian

------------
My Photo album
http://public.fotki.com/hurst/
comments welcome



  #3  
Old December 20th 04, 08:05 PM
dylan
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Default

The ppi (pixels per inch) is simply related to printing, it sets the size of
the print. It makes no difference to your image.

When you print just set the size you want in page setup.


"Ian Hurst (Troyka)" wrote in message
...

hi i use paint shop pro quite often and have recently noticed the
(pixel per inch) ppi is only 72 on every photo i have taken with my
a80. anyone know why? is it the software reducing ppi?

thanks


Ian

------------
My Photo album
http://public.fotki.com/hurst/
comments welcome



  #4  
Old December 20th 04, 11:17 PM
Charles Schuler
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"Ian Hurst (Troyka)" wrote in message
...

hi i use paint shop pro quite often and have recently noticed the
(pixel per inch) ppi is only 72 on every photo i have taken with my
a80. anyone know why? is it the software reducing ppi?


72 ppi is a computer screen standard (I think it is based on an early
Macintosh). So, if you are sending pictures via email, 72 ppi is about all
one needs. Unfortunately, this default confuses us as some software assumes
it. Mostly, it can be ignored for other purposes such as printing,
archiving, etc.


  #5  
Old December 21st 04, 01:07 AM
RoseW
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hi i use paint shop pro quite often and have recently noticed the (pixel
per inch) ppi is only 72 on every photo i have taken with my a80. anyone
know why? is it the software reducing ppi?

------
On the forum at Jasc for Photography and Scrapbook this Resolution topic for
printing often occurs. The following is a response by a Jasc representative
Kris K. The person posting was asking about sizing his image in order to
take it to a printing service to get a 4 * 6 result.

RESOLUTION
If in PSP you do Image Resize and change the resolution ("Resample Using"
unchecked) the resolution value is changed the normal image data and also
in the EXIF header if present.

If you don't want the number of pixels in the image to change,please 'don't
check' - "Resample Using"- option. When this option is 'not checked' you
change only the' resolution'. As you change the resolution the size of the
image in physical units is modified to reflect the new resolution but the
size in pixels does not change.


When you open an image into PSP for editing it is not in 'any' format. The
image is a device independent bitmap. When you change the image and save it
you choose the format in which you wish it to be saved. If you choose a
lossless compression format such as PSP, TIFF or PNG there will be no JPEG
compression. If you choose the JPEG format the image will be compressed as
if it were being created for the first time. PSP has no way to know if the
image you are saving was, for instance, opened and then filled with
completely new data or opened and changed in a minor way.
Consequently all saving is done as if you were dealing with a newly created
image.

-----------

PaintShoPro.Photography newsgroup is available via server
userforums.jasc.com and digital images are accepted. This forum is available
at the jasc.com site also

Rose


  #6  
Old December 21st 04, 04:16 AM
Gary Eickmeier
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Jim Townsend wrote:

If you take this file, change it to say 10 inches wide @ 72dpi and make
sure you *resample*, then it will become a 72dpi x 10inches = 720 pixels
wide which will fit in most monitors.

It's not the fact that the file is 72dpi that makes it fit, it's the
fact it was resampled from 3535 to 720 pixels across..


This isn't very helpful info, Jim. He's trying to get his image greater
than 72 ppi, and doesn't know about resizing without resampling.

Gary Eickmeier
  #7  
Old December 21st 04, 05:24 AM
Crownfield
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Gary Eickmeier wrote:

Jim Townsend wrote:

If you take this file, change it to say 10 inches wide @ 72dpi and make
sure you *resample*, then it will become a 72dpi x 10inches = 720 pixels
wide which will fit in most monitors.

It's not the fact that the file is 72dpi that makes it fit, it's the
fact it was resampled from 3535 to 720 pixels across..


This isn't very helpful info, Jim. He's trying to get his image greater
than 72 ppi, and doesn't know about resizing without resampling.


or is he simply distracted by dpi,
when he does not need to pay any attention to that number?



Gary Eickmeier

  #8  
Old December 21st 04, 08:23 AM
Colin D
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hi i use paint shop pro quite often and have recently noticed the
(pixel per inch) ppi is only 72 on every photo i have taken with my
a80. anyone know why? is it the software reducing ppi?


The image from the camera does not have any 'ppi' at all. It is simply
a 2000 x 3000 or whatever pixel count the camera sensor delivers. It is
a dimensionless collection of pixels.

However, when the image is opened in a graphics program, in order to
display the image, the program will use a default ppi. It is the
graphics program which does this, and not a feature of the image
itself. If your graphics program has an image size function, you can
alter the ppi *without* resampling, whereupon the image size changes.
F'rinstance, if your program defaults to 72 ppi, and the image size is
2000 x 3000 pixels, the apparent size on the screen will 2000/72 x
3000/72 inches, that's 27 x 42 inches approx. Which is why you can't
see the whole picture at once. If you tell the program to display the
image at, say, 600 ppi, the image will then be about 3 x 5 inches *on
the screen*. The image itself hasn't been changed at all, only the
pixel display pitch has changed.

The same goes for printing. Specify a size for printing, and the image
delivered to the printer will be at such a ppi as will give the required
size.

NOTE none of the foregoing has resampled the image. If you want to
send a picture over the net, at a given size, say, 5 x 7, at 72 ppi,
then you will have to resample, that is, change the pixel count so that
the image at 72ppi will produce a 5 x 7 image on screen. Now, a 5 x 7
image at 72ppi will be 5*72 * 7*72 pixels, that is, 504 x 360 pixels,
which is an image of 181,440 pixels (far smaller than the 6 million
pixels in the original image. Inevitably, you lose information when you
do this, so don't do it to your original image!!), and a Jpeg file with
about a 10:1 compression will be about 18 kilobytes, a suitable size for
sending over the net.

Hope this helps,

Colin

  #9  
Old December 21st 04, 08:23 AM
Colin D
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Posts: n/a
Default

hi i use paint shop pro quite often and have recently noticed the
(pixel per inch) ppi is only 72 on every photo i have taken with my
a80. anyone know why? is it the software reducing ppi?


The image from the camera does not have any 'ppi' at all. It is simply
a 2000 x 3000 or whatever pixel count the camera sensor delivers. It is
a dimensionless collection of pixels.

However, when the image is opened in a graphics program, in order to
display the image, the program will use a default ppi. It is the
graphics program which does this, and not a feature of the image
itself. If your graphics program has an image size function, you can
alter the ppi *without* resampling, whereupon the image size changes.
F'rinstance, if your program defaults to 72 ppi, and the image size is
2000 x 3000 pixels, the apparent size on the screen will 2000/72 x
3000/72 inches, that's 27 x 42 inches approx. Which is why you can't
see the whole picture at once. If you tell the program to display the
image at, say, 600 ppi, the image will then be about 3 x 5 inches *on
the screen*. The image itself hasn't been changed at all, only the
pixel display pitch has changed.

The same goes for printing. Specify a size for printing, and the image
delivered to the printer will be at such a ppi as will give the required
size.

NOTE none of the foregoing has resampled the image. If you want to
send a picture over the net, at a given size, say, 5 x 7, at 72 ppi,
then you will have to resample, that is, change the pixel count so that
the image at 72ppi will produce a 5 x 7 image on screen. Now, a 5 x 7
image at 72ppi will be 5*72 * 7*72 pixels, that is, 504 x 360 pixels,
which is an image of 181,440 pixels (far smaller than the 6 million
pixels in the original image. Inevitably, you lose information when you
do this, so don't do it to your original image!!), and a Jpeg file with
about a 10:1 compression will be about 18 kilobytes, a suitable size for
sending over the net.

Hope this helps,

Colin

  #10  
Old December 21st 04, 02:34 PM
Gary Eickmeier
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Default



Crownfield wrote:

or is he simply distracted by dpi,
when he does not need to pay any attention to that number?


It's amazing how many of these posts we get per month. It was the first
subject I studied when I got into digital imaging, thanks to Wayne
Fulton (http://scantips.com/) and a few instruction manuals. We should
just have a stock answer or reference to a FAQ and let it go at that.

Gary Eickmeier
 




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