[scribus] pdf compression

[Peter Nermander]

> Before the images went into Scribus, they were all cropped to the
> bone.  I'm puzzled by one thing (well, too many things to count, but
> only that that may be pertinent),  The Scribus image-info generally
> says original ppi 300, actual ppi 400+.  I scanned or Photoshopped
> everything to 300.  What does the 400+ mean?  I need 300. Do I have

The DPI of an image is a result of the resolution (number of pixels)
and the physical printing size.

If you have an image of 3000x3000 pixels in your computer it does not
have a DPI (because the physical dimensions are not known). A digital
image on your disk can never have a DPI, since it does not have any
physical dimensions. It only gets physical dimensions once you print
it or show it on screen. The DPI figure in an image file is only
information, not a property of the image.

If you print that image as 10x10 inches you will print it at 300 DPI.
If you print the same image at 8x8 inches you will print it at 375
DPI.

So, the question that pops up is: for what physical printing size did
you crop it to 300 DPI for?

I think Scribus honors the DPI information in the image by scaling the
image. If you scale the image to 100% I think it will print to the DPI
in the image information. But if you scale it to something else than
100% it will of course print in that size and DPI.

The best way to get an image to the right size is to start with the
printing size. You want to print the image 4x6 inches at 300 DPI? Then
the resolution shall be 1200x2400 (simple multiplication) and in
Scribus you set the image frame to 4x6 inches and fit the image to
frame.

/Peter