Saving JPEG without changing resolution?

Saving JPEG without changing resolution?

Post by Robert Nichols » Wed, 22 Jan 2003 03:39:16



If I load a JPEG into Photoshop whenever I save it via "Save As" it will
always save it as a 72dpi JPEG.

How can I maintain the same resolution when saving this file?

I'm only trying to rotate it.

 
 
 

Saving JPEG without changing resolution?

Post by TATM » Wed, 22 Jan 2003 04:25:39


Wasn't the file you're modifying 72dpi?

As far as I'm concerned, when I save a jpeg, I keep the resolution. You can
check the resolution in Image Size.

However, how can you need to change the resolution for a jpeg?
I mean, pictures in jpeg are only to be lossy bitmaps (for the web...). If
you're trying to print, first using a jpeg is not the greatest, and then
printing a jpeg usualy takes the printer resolution in count (and so the
size in pixels).

Am I wrong?

TATMF

 
 
 

Saving JPEG without changing resolution?

Post by Taci » Wed, 22 Jan 2003 05:17:46


Quote:>If I load a JPEG into Photoshop whenever I save it via "Save As" it will
>always save it as a 72dpi JPEG.

>How can I maintain the same resolution when saving this file?

Opening a JPEG and re-saving it does not change the resolution. What makes you
think the resolution is changing?

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Saving JPEG without changing resolution?

Post by Brian » Wed, 22 Jan 2003 05:40:06


"Save as" preserves the resolution. "Save for Web" changes the resolution to
72 ppi.

Brian


Quote:> If I load a JPEG into Photoshop whenever I save it via "Save As" it will
> always save it as a 72dpi JPEG.

> How can I maintain the same resolution when saving this file?

> I'm only trying to rotate it.

 
 
 

Saving JPEG without changing resolution?

Post by S. S » Wed, 22 Jan 2003 08:04:10


Resolution makes sense only for printing, it doesn't matter what it
says when you save your picture. What matters is size in pixels. Still
you can always go to Image->Size, uncheck "resample" box and set
resolution to (almost) anything you want - you'll see that print size
will change accordingly, so that each print dimension (in inches)
multiplied by resolution equals to number of pixels in this dimension.
If you just want to rotate JPEG file try Irfanview software: it's free
and does lossless rotation. PS does lossless rotation as well but you
have to save the new, rotated, version of your image and every time
you save in JPEG there's a quality loss.
Sergey

oh - what I said is true only for 90 degree rotations, otherwise
rotation will reduce the quality!


> If I load a JPEG into Photoshop whenever I save it via "Save As" it will
> always save it as a 72dpi JPEG.

> How can I maintain the same resolution when saving this file?

> I'm only trying to rotate it.

 
 
 

Saving JPEG without changing resolution?

Post by Brian » Wed, 22 Jan 2003 14:30:50


Is rotation in Windows Explorer  lossless? (right click,rotate ...)

Brian


> Resolution makes sense only for printing, it doesn't matter what it
> says when you save your picture. What matters is size in pixels. Still
> you can always go to Image->Size, uncheck "resample" box and set
> resolution to (almost) anything you want - you'll see that print size
> will change accordingly, so that each print dimension (in inches)
> multiplied by resolution equals to number of pixels in this dimension.
> If you just want to rotate JPEG file try Irfanview software: it's free
> and does lossless rotation. PS does lossless rotation as well but you
> have to save the new, rotated, version of your image and every time
> you save in JPEG there's a quality loss.
> Sergey

> oh - what I said is true only for 90 degree rotations, otherwise
> rotation will reduce the quality!




- Show quoted text -

Quote:> > If I load a JPEG into Photoshop whenever I save it via "Save As" it will
> > always save it as a 72dpi JPEG.

> > How can I maintain the same resolution when saving this file?

> > I'm only trying to rotate it.

 
 
 

Saving JPEG without changing resolution?

Post by Robert Nichols » Wed, 22 Jan 2003 18:17:53


If I open a file that's


in the browser.

I then rotate it and then save it
saves a file that claims then to be


So I guess it's not changing the resolution just reporting
it a different way.

Why does it do that?


> >If I load a JPEG into Photoshop whenever I save it via "Save As" it will
> >always save it as a 72dpi JPEG.

> >How can I maintain the same resolution when saving this file?

> Opening a JPEG and re-saving it does not change the resolution. What makes you
> think the resolution is changing?

 
 
 

Saving JPEG without changing resolution?

Post by Dean Van Praot » Wed, 22 Jan 2003 23:59:24



>If I open a file that's


>in the browser.

>I then rotate it and then save it
>saves a file that claims then to be


>So I guess it's not changing the resolution just reporting
>it a different way.

>Why does it do that?

It's just Photoshop's way of defining image size.  
Useful when you need to send a particular image
resolution to the printer, odd when you're used
to other programs that might care only about the
raw pixel dimensions.
 
 
 

1. Saving JPGs without loss of resolution

Hello,

I would like to rotate a jpg picture by 90 degrees so that it is in the
correct position.  However, when I tryed it it saves it at a new
compression rate and it looses some of the resolution of the picture.
I would like to know how to rotate the picture without changing the
resolution.

Thank you very much,
  Claus

BTW.  I have access to PSP and LView.

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