[scribus] Reducing photo filesizes and dpi for PDFs

[Gregory Pittman]

On 01/09/2012 07:09 AM, Peter Nermander wrote:
>> That's strange because IF all photos are automagically reduced to the
>> 300 dpi set in the export dialog, they will make much less image surface
>> (and thus dots) than that single large map. There is also some text on
>> the page and gaps between the photos.
>
> If your images are JPEG the "file size" does not only depend on the
> number of pixels, but also the degree of compression.
>
> That is the reason that a JPEG with lower resolution might give a
> larger file size.
>
> In the same place where you set the maximum resolution you can also
> set the compression level.
>
> On of the hard things with JPEG is that you will usually have to test
> so see how much compression you can use without destroying the image.
> You can't say that one compression always looks ok and onother not,
> because it depends on the image content.
>

You might look at this wiki page for some guidance:

http://wiki.scribus.net/canvas/Image_DPI_and_Scaling,_and_Resultant_File_Sizes

where both external and internal compressions were done to show how file 
size and image quality change.

Greg